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Zhang XF, Li Z, Lin H, Cheng Y, Wang H, Jiang Z, Ji Z, Huang Z, Chen H, Wei T. A phytoplasma effector destabilizes chloroplastic glutamine synthetase inducing chlorotic leaves that attract leafhopper vectors. Proc Natl Acad Sci U S A 2024; 121:e2402911121. [PMID: 38776366 DOI: 10.1073/pnas.2402911121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Accepted: 04/22/2024] [Indexed: 05/25/2024] Open
Abstract
Leaf yellowing is a well-known phenotype that attracts phloem-feeding insects. However, it remains unclear how insect-vectored plant pathogens induce host leaf yellowing to facilitate their own transmission by insect vectors. Here, we report that an effector protein secreted by rice orange leaf phytoplasma (ROLP) inhibits chlorophyll biosynthesis and induces leaf yellowing to attract leafhopper vectors, thereby presumably promoting pathogen transmission. This effector, designated secreted ROLP protein 1 (SRP1), first secreted into rice phloem by ROLP, was subsequently translocated to chloroplasts by interacting with the chloroplastic glutamine synthetase (GS2). The direct interaction between SRP1 and GS2 disrupts the decamer formation of the GS2 holoenzyme, attenuating its enzymatic activity, thereby suppressing the synthesis of chlorophyll precursors glutamate and glutamine. Transgenic expression of SRP1 in rice plants decreased GS2 activity and chlorophyll precursor accumulation, finally inducing leaf yellowing. This process is correlated with the previous evidence that the knockout of GS2 expression in rice plants causes a similar yellow chlorosis phenotype. Consistently, these yellowing leaves attracted higher numbers of leafhopper vectors, caused the vectors to probe more frequently, and presumably facilitate more efficient phytoplasma transmission. Together, these results uncover the mechanism used by phytoplasmas to manipulate the leaf color of infected plants for the purpose of enhancing attractiveness to insect vectors.
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Affiliation(s)
- Xiao-Feng Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Zhanpeng Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Hanbin Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Yu Cheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Huanqin Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Zhoumian Jiang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Zhenxi Ji
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Zhejun Huang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Hongyan Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Taiyun Wei
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
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Liu CY, Cheng HP, Lin CP, Liao YT, Ko TP, Lin SJ, Lin SS, Wang HC. Structural insights into the molecular mechanism of phytoplasma immunodominant membrane protein. IUCRJ 2024; 11:384-394. [PMID: 38656311 PMCID: PMC11067747 DOI: 10.1107/s2052252524003075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 04/09/2024] [Indexed: 04/26/2024]
Abstract
Immunodominant membrane protein (IMP) is a prevalent membrane protein in phytoplasma and has been confirmed to be an F-actin-binding protein. However, the intricate molecular mechanisms that govern the function of IMP require further elucidation. In this study, the X-ray crystallographic structure of IMP was determined and insights into its interaction with plant actin are provided. A comparative analysis with other proteins demonstrates that IMP shares structural homology with talin rod domain-containing protein 1 (TLNRD1), which also functions as an F-actin-binding protein. Subsequent molecular-docking studies of IMP and F-actin reveal that they possess complementary surfaces, suggesting a stable interaction. The low potential energy and high confidence score of the IMP-F-actin binding model indicate stable binding. Additionally, by employing immunoprecipitation and mass spectrometry, it was discovered that IMP serves as an interaction partner for the phytoplasmal effector causing phyllody 1 (PHYL1). It was then shown that both IMP and PHYL1 are highly expressed in the S2 stage of peanut witches' broom phytoplasma-infected Catharanthus roseus. The association between IMP and PHYL1 is substantiated through in vivo immunoprecipitation, an in vitro cross-linking assay and molecular-docking analysis. Collectively, these findings expand the current understanding of IMP interactions and enhance the comprehension of the interaction of IMP with plant F-actin. They also unveil a novel interaction pathway that may influence phytoplasma pathogenicity and host plant responses related to PHYL1. This discovery could pave the way for the development of new strategies to overcome phytoplasma-related plant diseases.
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Affiliation(s)
- Chang-Yi Liu
- The PhD Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Han-Pin Cheng
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, Taiwan
| | - Chan-Pin Lin
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, Taiwan
| | - Yi-Ting Liao
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Tzu-Ping Ko
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Shin-Jen Lin
- International Center for the Scientific Development of Shrimp Aquaculture, National Cheng Kung University, Tainan, Taiwan
| | - Shih-Shun Lin
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
- Center of Biotechnology, National Taiwan University of Science and Technology, Taipei, Taiwan
| | - Hao-Ching Wang
- The PhD Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
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3
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Wang R, Bai B, Li D, Wang J, Huang W, Wu Y, Zhao L. Phytoplasma: A plant pathogen that cannot be ignored in agricultural production-Research progress and outlook. MOLECULAR PLANT PATHOLOGY 2024; 25:e13437. [PMID: 38393681 PMCID: PMC10887288 DOI: 10.1111/mpp.13437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 02/01/2024] [Accepted: 02/04/2024] [Indexed: 02/25/2024]
Abstract
Phytoplasmas are phloem-restricted plant-pathogenic bacteria transmitted by insects. They cause diseases in a wide range of host plants, resulting in significant economic and ecological losses worldwide. Research on phytoplasmas has a long history, with significant progress being made in the past 30 years. Notably, with the rapid development of phytoplasma research, scientists have identified the primary agents involved in phytoplasma transmission, established classification and detection systems for phytoplasmas, and 243 genomes have been sequenced and assembled completely or to draft quality. Multiple possible phytoplasma effectors have been investigated, elucidating the molecular mechanisms by which phytoplasmas manipulate their hosts. This review summarizes recent advances in phytoplasma research, including identification techniques, host range studies, whole- or draft-genome sequencing, effector pathogenesis and disease control methods. Additionally, future research directions in the field of phytoplasma research are discussed.
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Affiliation(s)
- Ruotong Wang
- State Key Laboratory for Crop Stress Resistance and High‐Efficiency ProductionNorthwest A&F UniversityYanglingShaanxiChina
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau, Ministry of Agriculture and Rural Affairs, College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
| | - Bixin Bai
- State Key Laboratory for Crop Stress Resistance and High‐Efficiency ProductionNorthwest A&F UniversityYanglingShaanxiChina
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau, Ministry of Agriculture and Rural Affairs, College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
| | - Danyang Li
- State Key Laboratory for Crop Stress Resistance and High‐Efficiency ProductionNorthwest A&F UniversityYanglingShaanxiChina
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau, Ministry of Agriculture and Rural Affairs, College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
| | - Jingke Wang
- State Key Laboratory for Crop Stress Resistance and High‐Efficiency ProductionNorthwest A&F UniversityYanglingShaanxiChina
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau, Ministry of Agriculture and Rural Affairs, College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
| | - Weijie Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghaiChina
| | - Yunfeng Wu
- State Key Laboratory for Crop Stress Resistance and High‐Efficiency ProductionNorthwest A&F UniversityYanglingShaanxiChina
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau, Ministry of Agriculture and Rural Affairs, College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
| | - Lei Zhao
- State Key Laboratory for Crop Stress Resistance and High‐Efficiency ProductionNorthwest A&F UniversityYanglingShaanxiChina
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau, Ministry of Agriculture and Rural Affairs, College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
- Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant ProtectionNorthwest A&F UniversityYanglingShaanxiChina
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Du P, Hu J, Du M, Gao X, Yang W, Zhang C, Zou X, Wang X, Li W. Interaction of a bacterial non-classically secreted RNase HⅠ with a citrus B-Box zinc finger protein delays flowering in Arabidopsis thaliana and suppresses the expression of FLOWERING LOCUS T. Microbiol Res 2024; 278:127541. [PMID: 37972521 DOI: 10.1016/j.micres.2023.127541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/21/2023] [Accepted: 10/31/2023] [Indexed: 11/19/2023]
Abstract
Ribonuclease HI (RNase HI) is well conserved across prokaryotes and eukaryotes, and has long been known to localize in the nucleic acid-containing cellular compartments for acting as an R-loop eraser but has never been determined to be a secreted protein. "Candidatus Liberibacter asiaticus" (CLas) is a fastidious α-proteobacterium that causes Huanglongbing (HLB), a devastating citrus disease often associated with flowering out of season. In this study, using the SecretomeP program coupled with an Escherichia coli-based alkaline phosphatase assay, we demonstrated that the CLas RNase HI (LasRNHⅠ) was a non-classically secreted protein. Further experiments identified that LasRNHⅠ could interact with a citrus B-box zinc finger protein CsBBX28 in the plant nucleolus. The in vitro assays indicated that CsBBX28 dramatically enhanced the R-loop-degrading activity of LasRNHⅠ. Remarkably, co-expression of CsBBX28 and LasRNHⅠ in Arabidopsis thaliana led to a much later flowering time than that of wild-type Arabidopsis, as well as that of the transgenic A. thaliana expressing only CsBBX28 or LasRNHⅠ, and lastingly and significantly repressed transcription of FLOWERING LOCUS T (FT), a floral pathway integrator. Similarly, ectopic expression of LasRNHⅠ in citrus greatly reduced the transcription level of FT. The data together disclosed the extracellular secretion of LasRNHⅠ, and that LasRNHⅠ physically interacted with CsBBX28 and served as a flowering repressor through suppressing the FT expression, suggesting a novel role of RNase HI in the bacteria interacting with the host plants.
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Affiliation(s)
- Peixiu Du
- Key Laboratory for Northern Urban Agriculture of Ministry of Agriculture and Rural Affairs, Beijing University of Agriculture, Beijing 102206, PR China; Innovative Institute of Chinese Medicine and Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan 250355, PR China; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Junxia Hu
- Department of Plant Protection, Beijing University of Agriculture, Beijing 102206, PR China
| | - Meixia Du
- Citrus Research Institute, Southwest University, Chongqing 400716, PR China
| | - Xiaoyu Gao
- Department of Plant Protection, Beijing University of Agriculture, Beijing 102206, PR China
| | - Wendi Yang
- Department of Plant Protection, Beijing University of Agriculture, Beijing 102206, PR China
| | - Chao Zhang
- College of Life Science, Hebei Agricultural University, Baoding 071001, PR China
| | - Xiuping Zou
- Citrus Research Institute, Southwest University, Chongqing 400716, PR China
| | - Xuefeng Wang
- Citrus Research Institute, Southwest University, Chongqing 400716, PR China
| | - Weimin Li
- Key Laboratory for Northern Urban Agriculture of Ministry of Agriculture and Rural Affairs, Beijing University of Agriculture, Beijing 102206, PR China; Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; Department of Plant Protection, Beijing University of Agriculture, Beijing 102206, PR China.
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5
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Suzuki M, Kitazawa Y, Iwabuchi N, Maejima K, Matsuyama J, Matsumoto O, Oshima K, Namba S, Yamaji Y. Target degradation specificity of phytoplasma effector phyllogen is regulated by the recruitment of host proteasome shuttle protein. MOLECULAR PLANT PATHOLOGY 2024; 25:e13410. [PMID: 38105442 PMCID: PMC10799209 DOI: 10.1111/mpp.13410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/16/2023] [Accepted: 11/17/2023] [Indexed: 12/19/2023]
Abstract
Phytoplasmas infect a wide variety of plants and can cause distinctive symptoms including the conversion of floral organs into leaf-like organs, known as phyllody. Phyllody is induced by an effector protein family called phyllogens, which interact with floral MADS-box transcription factors (MTFs) responsible for determining the identity of floral organs. The MTF/phyllogen complex then interacts with the proteasomal shuttle protein RADIATION SENSITIVE23 (RAD23), which facilitates delivery of the MTF/phyllogen complex to the host proteasome for MTF degradation. Previous studies have indicated that the MTF degradation specificity of phyllogens is determined by their ability to bind to MTFs. However, in the present study, we discovered a novel mechanism determining the degradation specificity through detailed functional analyses of a phyllogen homologue of rice yellow dwarf phytoplasma (PHYLRYD ). PHYLRYD degraded a narrower range of floral MTFs than other phyllody-inducing phyllogens, resulting in compromised phyllody phenotypes in plants. Interestingly, PHYLRYD was able to bind to some floral MTFs that PHYLRYD was unable to efficiently degrade. However, the complex of PHYLRYD and the non-degradable MTF could not interact with RAD23. These results indicate that the MTF degradation specificity of PHYLRYD is correlated with the ability to form the MTF/PHYLRYD /RAD23 ternary complex, rather than the ability to bind to MTF. This study elucidated that phyllogen target specificity is regulated by both the MTF-binding ability and RAD23 recruitment ability of the MTF/phyllogen complex.
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Affiliation(s)
- Masato Suzuki
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Yugo Kitazawa
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Nozomu Iwabuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Kensaku Maejima
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Juri Matsuyama
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Oki Matsumoto
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Kenro Oshima
- Faculty of Bioscience, Hosei UniversityTokyoJapan
| | - Shigetou Namba
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Yasuyuki Yamaji
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
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Chen P, Zhang Y, Li Y, Yang Q, Li Q, Chen L, Chen Y, Ye X, Tan B, Zheng X, Cheng J, Wang W, Li J, Feng J. Jujube Witches' Broom Phytoplasma Effector Zaofeng3, a Homologous Effector of SAP54, Induces Abnormal Floral Organ Development and Shoot Proliferation. PHYTOPATHOLOGY 2024; 114:200-210. [PMID: 37435950 DOI: 10.1094/phyto-10-21-0448-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/13/2023]
Abstract
Plant-pathogenic phytoplasmas secrete specific virulence proteins into a host plant to modulate plant function for their own benefit. Identification of phytoplasmal effectors is a key step toward clarifying the pathogenic mechanisms of phytoplasma. In this study, Zaofeng3, also known as secreted jujube witches' broom phytoplasma protein 3 (SJP3), was a homologous effector of SAP54 and induced a variety of abnormal phenotypes, such as phyllody, malformed floral organs, witches' broom, and dwarfism in Arabidopsis thaliana. Zaofeng3 can also induce small leaves, dwarfism, and witches' broom in Ziziphus jujuba. Further experiments showed that the three complete α-helix domains predicted in Zaofeng3 were essential for induction of disease symptoms in jujube. Yeast two-hybrid library screening showed that Zaofeng3 mainly interacts with proteins involved in flower morphogenesis and shoot proliferation. Bimolecular fluorescence complementation assays confirmed that Zaofeng3 interacted with these proteins in the whole cell. Overexpression of zaofeng3 in jujube shoot significantly altered the expression patterns of ZjMADS19, ZjMADS47, ZjMADS48, ZjMADS77, and ZjTCP7, suggesting that overexpressing zaofeng3 might induce floral organ malformation and witches' broom by altering the expression of the transcriptional factors involved in jujube morphogenesis.
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Affiliation(s)
- Peng Chen
- College of Landscape Architecture and Art, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Yu Zhang
- College of Forestry, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Yonghua Li
- College of Landscape Architecture and Art, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Qiqi Yang
- College of Forestry, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Qicheng Li
- College of Forestry, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Lichuan Chen
- College of Forestry, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Yun Chen
- College of Forestry, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Xia Ye
- College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Bin Tan
- College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Xianbo Zheng
- College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Jun Cheng
- College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Wei Wang
- College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Jidong Li
- College of Forestry, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
| | - Jiancan Feng
- College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Jinshui District, Zhengzhou 450002, China
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Tokuda R, Iwabuchi N, Kitazawa Y, Nijo T, Suzuki M, Maejima K, Oshima K, Namba S, Yamaji Y. Potential mobile units drive the horizontal transfer of phytoplasma effector phyllogen genes. Front Genet 2023; 14:1132432. [PMID: 37252660 PMCID: PMC10210161 DOI: 10.3389/fgene.2023.1132432] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 04/03/2023] [Indexed: 05/31/2023] Open
Abstract
Phytoplasmas are obligate intracellular plant pathogenic bacteria that can induce phyllody, which is a type of abnormal floral organ development. Phytoplasmas possess phyllogens, which are effector proteins that cause phyllody in plants. Phylogenetic comparisons of phyllogen and 16S rRNA genes have suggested that phyllogen genes undergo horizontal transfer between phytoplasma species and strains. However, the mechanisms and evolutionary implications of this horizontal gene transfer are unclear. Here, we analyzed synteny in phyllogen flanking genomic regions from 17 phytoplasma strains that were related to six 'Candidatus' species, including three strains newly sequenced in this study. Many of the phyllogens were flanked by multicopy genes within potential mobile units (PMUs), which are putative transposable elements found in phytoplasmas. The multicopy genes exhibited two distinct patterns of synteny that correlated with the linked phyllogens. The low level of sequence identities and partial truncations found among these phyllogen flanking genes indicate that the PMU sequences are deteriorating, whereas the highly conserved sequences and functions (e.g., inducing phyllody) of the phyllogens suggest that the latter are important for phytoplasma fitness. Furthermore, although their phyllogens were similar, PMUs in strains related to 'Ca. P. asteris' were often located in different regions of the genome. These findings strongly indicate that PMUs drive the horizontal transfer of phyllogens among phytoplasma species and strains. These insights improve our understanding of how symptom-determinant genes have been shared among phytoplasmas.
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Affiliation(s)
- Ryosuke Tokuda
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Nozomu Iwabuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yugo Kitazawa
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Takamichi Nijo
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Masato Suzuki
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kensaku Maejima
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kenro Oshima
- Faculty of Bioscience and Applied Chemistry, Hosei University, Tokyo, Japan
| | - Shigetou Namba
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yasuyuki Yamaji
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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Kitazawa Y, Iwabuchi N, Maejima K, Matsumoto O, Suzuki M, Matsuyama J, Koinuma H, Oshima K, Namba S, Yamaji Y. Random mutagenesis-based screening of the interface of phyllogen, a bacterial phyllody-inducing effector, for interaction with plant MADS-box proteins. FRONTIERS IN PLANT SCIENCE 2023; 14:1058059. [PMID: 37056494 PMCID: PMC10086140 DOI: 10.3389/fpls.2023.1058059] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 03/01/2023] [Indexed: 06/19/2023]
Abstract
To understand protein function deeply, it is important to identify how it interacts physically with its target. Phyllogen is a phyllody-inducing effector that interacts with the K domain of plant MADS-box transcription factors (MTFs), which is followed by proteasome-mediated degradation of the MTF. Although several amino acid residues of phyllogen have been identified as being responsible for the interaction, the exact interface of the interaction has not been elucidated. In this study, we comprehensively explored interface residues based on random mutagenesis using error-prone PCR. Two novel residues, at which mutations enhanced the affinity of phyllogen to MTF, were identified. These residues, and all other known interaction-involved residues, are clustered together at the surface of the protein structure of phyllogen, indicating that they constitute the interface of the interaction. Moreover, in silico structural prediction of the protein complex using ColabFold suggested that phyllogen interacts with the K domain of MTF via the putative interface. Our study facilitates an understanding of the interaction mechanisms between phyllogen and MTF.
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Affiliation(s)
- Yugo Kitazawa
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Nozomu Iwabuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kensaku Maejima
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Oki Matsumoto
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Masato Suzuki
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Juri Matsuyama
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Hiroaki Koinuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kenro Oshima
- Faculty of Bioscience and Applied Chemistry, Hosei University, Tokyo, Japan
| | - Shigetou Namba
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yasuyuki Yamaji
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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Bai B, Zhang G, Pei B, Song Q, Hao X, Zhao L, Wu Y. The function of the phytoplasma effector SWP12 depends on the properties of two key amino acids. J Biol Chem 2023; 299:103052. [PMID: 36813236 PMCID: PMC10040895 DOI: 10.1016/j.jbc.2023.103052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/23/2023] Open
Abstract
Phytoplasmas are insect-borne bacterial pathogens capable of secreting effectors into host cells and interfering with host plant defense response processes. Previous studies have found that the Candidatus Phytoplasma tritici effector SWP12 binds to and destabilizes the wheat transcription factor TaWRKY74, increasing wheat susceptibility to phytoplasmas. Here, we used a Nicotiana benthamiana transient expression system to identify two key functional sites of SWP12 and screened a series of truncated mutants and amino acid substitution mutants to determine whether they inhibit Bax-induced cell death. Using a subcellular localization assay and online structure analysis websites, we found that structure rather than intracellular localization probably affects the function of SWP12. D33A and P85H are two inactive substitution mutants, neither of which interacts with TaWRKY74, and P85H does not inhibit Bax-induced cell death, suppress flg22-triggered reactive oxygen species (ROS) bursts, degrade TaWRKY74, or promote phytoplasma accumulation. D33A can weakly suppress Bax-induced cell death and flg22-triggered ROS bursts and degrade a portion of TaWRKY74 and weakly promote phytoplasma accumulation. S53L, CPP, and EPWB are three SWP12 homolog proteins from other phytoplasmas. Sequence analysis revealed that D33 was conserved in these proteins, and they exhibited the same polarity at P85. Transient expression in N. benthamiana showed that these proteins could inhibit Bax-induced cell death and suppress ROS bursts. Our findings clarified that P85 and D33 of SWP12 play critical and minor roles, respectively, in suppressing the plant defense response and that they play a preliminary role in determining the functions of homologous proteins.
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Affiliation(s)
- Bixin Bai
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Guoding Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Baoyan Pei
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Qingting Song
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Xing'an Hao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Lei Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
| | - Yunfeng Wu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
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10
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Chiu YC, Liao PQ, Mejia HM, Lee YC, Chen YK, Yang JY. Detection, Identification and Molecular Characterization of the 16SrII-V Subgroup Phytoplasma Strain Associated with Pisum sativum and Parthenium hysterophorus L. PLANTS (BASEL, SWITZERLAND) 2023; 12:891. [PMID: 36840237 PMCID: PMC9962045 DOI: 10.3390/plants12040891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
Two unrelated plant species, green pea and parthenium weed, harboring typical phytoplasma symptoms, were discovered in Yunlin, Taiwan. Green pea (Pisum sativum.) and parthenium weed (Parthenium hysterophorus L.) are both herbaceous annual plants belonging to the Fabaceae and Asteraceae families, respectively. Displayed symptoms were witches' broom, phyllody and virescence, which are typical indications of phytoplasma infection. Pleomorphic phytoplasma-like bodies were observed under the transmission electron microscope in the sieve elements of symptomatic green pea and parthenium weed. The iPhyClassifier-based virtual RFLP study demonstrated that the phytoplasma associated with the diseased plants belongs to the 16SrII-V subgroup. The disease symptoms of both plants can be explained by the identification of PHYL1 and SAP11 effectors, identical to those of peanut witches' broom phytoplasma. The phytoplasma strains identified in this study present a very close phylogenetic relationship with other 16SrII-V subgroup phytoplasma strains discovered in Taiwan. These results not only convey the local status of the 16SrII-V subgroup phytoplasma strains but also encourage attention to be given to preventing the spread of this threat before it becomes pervasive.
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Affiliation(s)
- Yi-Ching Chiu
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
- PhD Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung 402, Taiwan
| | - Pei-Qing Liao
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Helen Mae Mejia
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Ya-Chien Lee
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Yuh-Kun Chen
- Department of Plant Pathology, National Chung Hsing University, Taichung 402, Taiwan
| | - Jun-Yi Yang
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
- PhD Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung 402, Taiwan
- Institute of Biotechnology, National Chung Hsing University, Taichung 402, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
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11
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Kong F, Yang L. Pathogen-triggered changes in plant development: Virulence strategies or host defense mechanism? Front Microbiol 2023; 14:1122947. [PMID: 36876088 PMCID: PMC9975269 DOI: 10.3389/fmicb.2023.1122947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 01/25/2023] [Indexed: 02/17/2023] Open
Abstract
Plants, as sessile organisms, are constantly exposed to pathogens in nature. Plants rely on physical barriers, constitutive chemical defenses, and sophisticated inducible immunity to fight against pathogens. The output of these defense strategies is highly associated with host development and morphology. Successful pathogens utilize various virulence strategies to colonize, retrieve nutrients, and cause disease. In addition to the overall defense-growth balance, the host-pathogen interactions often lead to changes in the development of specific tissues/organs. In this review, we focus on recent advances in understanding the molecular mechanisms of pathogen-induced changes in plants' development. We discuss that changes in host development could be a target of pathogen virulence strategies or an active defense strategy of plants. Current and ongoing research about how pathogens shape plant development to increase their virulence and causes diseases could give us novel views on plant disease control.
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Affiliation(s)
- Feng Kong
- Department of Plant Pathology, University of Georgia, Athens, GA, United States
| | - Li Yang
- Department of Plant Pathology, University of Georgia, Athens, GA, United States
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12
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Mejia HM, Liao PQ, Chen YK, Lee YC, Tan CM, Chiu YC, Yang JY. Detection, Identification, and Molecular Characterization of the 16SrII-V Subgroup Phytoplasma Strain Associated with Digera muricata in Taiwan. PLANT DISEASE 2022; 106:1788-1792. [PMID: 35072504 DOI: 10.1094/pdis-12-21-2647-sc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Digera muricata (L.) Mart. is a pantropical annual herb belonging to the Amaranthaceae family. In August 2021, D. muricata with indicative phytoplasma symptoms of phyllody, witches'-broom, and virescence was discovered adjacent to a peanut field in Mailiao, Yunlin, Taiwan. The causal agent of the observed symptoms was detected and identified by a series of molecular characterizations. Sieve elements of the phloem tissue were perused under the transmission electron microscope and revealed the presence of pleomorphic phytoplasma-like organisms. Nested PCR using phytoplasma universal primer pairs P1/P7 and R16F2n/R16R2 was able to amplify a 1.2-kb DNA fragment for the 16S rRNA gene only from the symptomatic D. muricata. The 16S rRNA-based phylogenetic analysis and the iPhyClassifier-based virtual RFLP further affirmed that the phytoplasma associated with the diseased D. muricata can be classified into the 16SrII-V subgroup. Moreover, displayed evident symptoms were explained by the concomitant detection of PHYL1 and SAP11, the virulence genes responsible for the development of leaf-like flowers and shoot proliferation, respectively. Although phytoplasma infection on the noncrop species does not have a direct economic impact, its role in disease spread and perpetuation is indubitable.
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Affiliation(s)
- Helen Mae Mejia
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Pei-Qing Liao
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Yuh-Kun Chen
- Department of Plant Pathology, National Chung Hsing University, Taichung 402, Taiwan
| | - Ya-Chien Lee
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Choon Meng Tan
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Yi-Ching Chiu
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
- Doctoral Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung 402, Taiwan
| | - Jun-Yi Yang
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
- Doctoral Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung 402, Taiwan
- Institute of Biotechnology, National Chung Hsing University, Taichung 402, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
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13
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Bertaccini A. Plants and Phytoplasmas: When Bacteria Modify Plants. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11111425. [PMID: 35684198 PMCID: PMC9182842 DOI: 10.3390/plants11111425] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 05/18/2022] [Accepted: 05/24/2022] [Indexed: 05/14/2023]
Abstract
Plant pathogen presence is very dangerous for agricultural ecosystems and causes huge economic losses. Phytoplasmas are insect-transmitted wall-less bacteria living in plants, only in the phloem tissues and in the emolymph of their insect vectors. They are able to manipulate several metabolic pathways of their hosts, very often without impairing their life. The molecular diversity described (49 'Candidatus Phytoplasma' species and about 300 ribosomal subgroups) is only in some cases related to their associated symptomatology. As for the other plant pathogens, it is necessary to verify their identity and recognize the symptoms associated with their presence to appropriately manage the diseases. However, the never-ending mechanism of patho-adaptation and the copresence of other pathogens makes this management difficult. Reducing the huge impact of phytoplasma-associated diseases in all the main crops and wild species is, however, relevant, in order to reduce their effects that are jeopardizing plant biodiversity.
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Affiliation(s)
- Assunta Bertaccini
- Department of Agricultural and Food Sciences, Alma Mater Studiorum-University of Bologna, 40127 Bologna, Italy
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14
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Kitazawa Y, Iwabuchi N, Maejima K, Sasano M, Matsumoto O, Koinuma H, Tokuda R, Suzuki M, Oshima K, Namba S, Yamaji Y. A phytoplasma effector acts as a ubiquitin-like mediator between floral MADS-box proteins and proteasome shuttle proteins. THE PLANT CELL 2022; 34:1709-1723. [PMID: 35234248 PMCID: PMC9048881 DOI: 10.1093/plcell/koac062] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/14/2022] [Indexed: 06/01/2023]
Abstract
Plant pathogenic bacteria have developed effectors to manipulate host cell functions to facilitate infection. A certain number of effectors use the conserved ubiquitin-proteasome system in eukaryotic to proteolyze targets. The proteasome utilization mechanism is mainly mediated by ubiquitin interaction with target proteins destined for degradation. Phyllogens are a family of protein effectors produced by pathogenic phytoplasmas that transform flowers into leaves in diverse plants. Here, we present a noncanonical mechanism for phyllogen action that involves the proteasome and is ubiquitin-independent. Phyllogens induce proteasomal degradation of floral MADS-box transcription factors (MTFs) in the presence of RADIATION-SENSITIVE23 (RAD23) shuttle proteins, which recruit ubiquitinated proteins to the proteasome. Intracellular localization analysis revealed that phyllogen induced colocalization of MTF with RAD23. The MTF/phyllogen/RAD23 ternary protein complex was detected not only in planta but also in vitro in the absence of ubiquitin, showing that phyllogen directly mediates interaction between MTF and RAD23. A Lys-less nonubiquitinated phyllogen mutant induced degradation of MTF or a Lys-less mutant of MTF. Furthermore, the method of sequential formation of the MTF/phyllogen/RAD23 protein complex was elucidated, first by MTF/phyllogen interaction and then RAD23 recruitment. Phyllogen recognized both the evolutionarily conserved tetramerization region of MTF and the ubiquitin-associated domain of RAD23. Our findings indicate that phyllogen functionally mimics ubiquitin as a mediator between MTF and RAD23.
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Affiliation(s)
- Yugo Kitazawa
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Nozomu Iwabuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | | | - Momoka Sasano
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Oki Matsumoto
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Hiroaki Koinuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Ryosuke Tokuda
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Masato Suzuki
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Kenro Oshima
- Faculty of Bioscience and Applied Chemistry, Hosei University, Tokyo 184-8584, Japan
| | - Shigetou Namba
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Yasuyuki Yamaji
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
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15
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Liao PQ, Chen YK, Mejia HM, Chien YY, Lee YC, Tan CM, Chiu YC, Yang JY. Detection, Identification, and Molecular Characterization of a 16SrII-V Subgroup Phytoplasma Associated with Nicotiana plumbaginifolia. PLANT DISEASE 2022; 106:805-809. [PMID: 34763517 DOI: 10.1094/pdis-09-21-1968-sc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Nicotiana plumbaginifolia Viviani, commonly known as curl-leaved tobacco, is an annual herbaceous plant belonging to Solanaceae family. This plant is native to Mexico, South America, and parts of the Caribbean and has been reported to be present in Taiwan since 2006. In March 2021, N. plumbaginifolia Viviani, found in Yunlin County, Taiwan, was observed to have phyllody, virescence, and witches'-broom, which is consistent with the disease symptoms caused by phytoplasma infection. Samples of the healthy and symptomatic plants were collected for analysis of the causal agent associated with the diseased N. plumbaginifolia Viviani. Under transmission electron microscopy, the phytoplasma-like pleomorphic bodies were found in the sieve tubes of the diseased plants. The 16S ribosomal RNA (rRNA)-based phylogenetic analysis and the iPhyClassifier-based virtual restriction fragment length polymorphism study demonstrated that the phytoplasma identified in this study can be classified into the 16SrII-V subgroup, which is similar to the peanut witches'-broom phytoplasma, a 'Candidatus phytoplasma aurantifolia'-related strain. Further identification of SAP54/PHYL1 and SAP11 homologs in the phytoplasma explain the disease symptoms of phyllody, virescence, and witches'-broom observed in diseased N. plumbaginifolia Viviani. The discovery of new phytoplasma plant hosts has gained scientific importance in light of the attempt to unravel an efficient strategy to fight the rapid spread of this disease, which poses a threat to the agricultural sector and food security in Taiwan.
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Affiliation(s)
- Pei-Qing Liao
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Yuh-Kun Chen
- Department of Plant Pathology, National Chung Hsing University, Taichung 402, Taiwan
| | - Helen Mae Mejia
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Yuan-Yu Chien
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Ya-Chien Lee
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Choon-Meng Tan
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Yi-Ching Chiu
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
- Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung 402, Taiwan
| | - Jun-Yi Yang
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
- Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung 402, Taiwan
- Institute of Biotechnology, National Chung Hsing University, Taichung 402, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
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16
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Huang CT, Cho ST, Lin YC, Tan CM, Chiu YC, Yang JY, Kuo CH. Comparative Genome Analysis of ‘Candidatus Phytoplasma luffae’ Reveals the Influential Roles of Potential Mobile Units in Phytoplasma Evolution. Front Microbiol 2022; 13:773608. [PMID: 35300489 PMCID: PMC8923039 DOI: 10.3389/fmicb.2022.773608] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 02/07/2022] [Indexed: 12/23/2022] Open
Abstract
Phytoplasmas are insect-transmitted plant pathogens that cause substantial losses in agriculture. In addition to economic impact, phytoplasmas induce distinct disease symptoms in infected plants, thus attracting attention for research on molecular plant-microbe interactions and plant developmental processes. Due to the difficulty of establishing an axenic culture of these bacteria, culture-independent genome characterization is a crucial tool for phytoplasma research. However, phytoplasma genomes have strong nucleotide composition biases and are repetitive, which make it challenging to produce complete assemblies. In this study, we utilized Illumina and Oxford Nanopore sequencing technologies to obtain the complete genome sequence of ‘Candidatus Phytoplasma luffae’ strain NCHU2019 that is associated with witches’ broom disease of loofah (Luffa aegyptiaca) in Taiwan. The fully assembled circular chromosome is 769 kb in size and is the first representative genome sequence of group 16SrVIII phytoplasmas. Comparative analysis with other phytoplasmas revealed that NCHU2019 has a remarkably repetitive genome, possessing a pair of 75 kb repeats and at least 13 potential mobile units (PMUs) that account for ∼25% of its chromosome. This level of genome repetitiveness is exceptional for bacteria, particularly among obligate pathogens with reduced genomes. Our genus-level analysis of PMUs demonstrated that these phytoplasma-specific mobile genetic elements can be classified into three major types that differ in gene organization and phylogenetic distribution. Notably, PMU abundance explains nearly 80% of the variance in phytoplasma genome sizes, a finding that provides a quantitative estimate for the importance of PMUs in phytoplasma genome variability. Finally, our investigation found that in addition to horizontal gene transfer, PMUs also contribute to intra-genomic duplications of effector genes, which may provide redundancy for subfunctionalization or neofunctionalization. Taken together, this work improves the taxon sampling for phytoplasma genome research and provides novel information regarding the roles of mobile genetic elements in phytoplasma evolution.
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Affiliation(s)
- Ching-Ting Huang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Shu-Ting Cho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Yu-Chen Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Choon-Meng Tan
- Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Ching Chiu
- Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan
- Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung, Taiwan
| | - Jun-Yi Yang
- Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan
- Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung, Taiwan
- Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
- *Correspondence: Jun-Yi Yang,
| | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
- Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung-Hsing University and Academia Sinica, Taipei, Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
- Chih-Horng Kuo,
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17
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Chen P, Chen L, Ye X, Tan B, Zheng X, Cheng J, Wang W, Yang Q, Zhang Y, Li J, Feng J. Phytoplasma effector Zaofeng6 induces shoot proliferation by decreasing the expression of ZjTCP7 in Ziziphus jujuba. HORTICULTURE RESEARCH 2022; 9:6510945. [PMID: 35043187 PMCID: PMC8769037 DOI: 10.1093/hr/uhab032] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 10/10/2021] [Accepted: 10/15/2021] [Indexed: 05/02/2023]
Abstract
The jujube witches' broom (JWB) phytoplasma is associated with witches' broom, dwarfism, and smaller leaves in jujube, resulting in yield losses. In this study, eight putative JWB effector proteins were identified from potential mobile units of the JWB genome. Among them, Zaofeng6 induced witches' broom symptoms in Arabidopsis and jujube. Zaofeng6-overexpressing Arabidopsis and unrooted jujube transformants displayed witches' broom-like shoot proliferation. Transient expression of Zaofeng6 induced hypersensitive response like cell death and expression of hypersensitive response marker genes, like harpin-induced gene 1 (H1N1), and the pathogenesis-related genes PR1, PR2, and PR3 in transformed Nicotiana benthamiana leaves, suggesting that Zaofeng6 could be a virulence effector. Yeast two-hybrid library screening and bimolecular fluorescence complementation confirmed that Zaofeng6 interacts with ZjTCP7 through its first two α-helix domains in the cell nuclei. ZjTCP7 mRNA and protein abundance decreased in Zaofeng6 transgenic jujube seedlings. The expression of some genes in the strigolactone signaling pathway (ZjCCD7, ZjCCD8, and CYP711A1) were down-regulated in jujube shoots overexpressing Zaofeng6 and in zjtcp7 CRISPR/Cas9 mutants. Zaofeng6 induces shoot proliferation through decreased expression of ZjTCP7 at the transcriptional and translational levels.
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Affiliation(s)
- Peng Chen
- College of Forestry, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
| | - Lichuan Chen
- College of Forestry, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
| | - Xia Ye
- College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
| | - Bin Tan
- College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
| | - Xianbo Zheng
- College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
| | - Jun Cheng
- College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
| | - Wei Wang
- College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
| | - Qiqi Yang
- College of Forestry, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
| | - Yu Zhang
- College of Forestry, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
| | - Jidong Li
- College of Forestry, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
- Corresponding author. E-mail: ;
| | - Jiancan Feng
- College of Horticulture, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
- College of Forestry, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, China
- Corresponding author. E-mail: ;
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18
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Omenge KM, Rümpler F, Kathalingam SS, Furch ACU, Theißen G. Studying the Function of Phytoplasma Effector Proteins Using a Chemical-Inducible Expression System in Transgenic Plants. Int J Mol Sci 2021; 22:ijms222413582. [PMID: 34948378 PMCID: PMC8703313 DOI: 10.3390/ijms222413582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 11/17/2022] Open
Abstract
Phytoplasmas are bacterial pathogens that live mainly in the phloem of their plant hosts. They dramatically manipulate plant development by secreting effector proteins that target developmental proteins of their hosts. Traditionally, the effects of individual effector proteins have been studied by ectopic overexpression using strong, ubiquitously active promoters in transgenic model plants. However, the impact of phytoplasma infection on the host plants depends on the intensity and timing of infection with respect to the developmental stage of the host. To facilitate investigations addressing the timing of effector protein activity, we have established chemical-inducible expression systems for the three most well-characterized phytoplasma effector proteins, SECRETED ASTER YELLOWS WITCHES’ BROOM PROTEIN 11 (SAP11), SAP54 and TENGU in transgenic Arabidopsis thaliana. We induced gene expression either continuously, or at germination stage, seedling stage, or flowering stage. mRNA expression was determined by quantitative reverse transcription PCR, protein accumulation by confocal laser scanning microscopy of GFP fusion proteins. Our data reveal tight regulation of effector gene expression and strong upregulation after induction. Phenotypic analyses showed differences in disease phenotypes depending on the timing of induction. Comparative phenotype analysis revealed so far unreported similarities in disease phenotypes, with all three effector proteins interfering with flower development and shoot branching, indicating a surprising functional redundancy of SAP54, SAP11 and TENGU. However, subtle but mechanistically important differences were also observed, especially affecting the branching pattern of the plants.
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Affiliation(s)
- Keziah M. Omenge
- Department of Genetics, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University Jena, Philosophenweg 12, 07743 Jena, Germany; (K.M.O.); (F.R.); (S.S.K.)
| | - Florian Rümpler
- Department of Genetics, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University Jena, Philosophenweg 12, 07743 Jena, Germany; (K.M.O.); (F.R.); (S.S.K.)
| | - Subha Suvetha Kathalingam
- Department of Genetics, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University Jena, Philosophenweg 12, 07743 Jena, Germany; (K.M.O.); (F.R.); (S.S.K.)
| | - Alexandra C. U. Furch
- Department of Plant Physiology, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University Jena, Dornburger Str. 159, 07743 Jena, Germany;
| | - Günter Theißen
- Department of Genetics, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University Jena, Philosophenweg 12, 07743 Jena, Germany; (K.M.O.); (F.R.); (S.S.K.)
- Correspondence:
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19
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Tan CM, Lin YC, Li JR, Chien YY, Wang CJ, Chou L, Wang CW, Chiu YC, Kuo CH, Yang JY. Accelerating Complete Phytoplasma Genome Assembly by Immunoprecipitation-Based Enrichment and MinION-Based DNA Sequencing for Comparative Analyses. Front Microbiol 2021; 12:766221. [PMID: 34858377 PMCID: PMC8632452 DOI: 10.3389/fmicb.2021.766221] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 10/11/2021] [Indexed: 11/13/2022] Open
Abstract
Phytoplasmas are uncultivated plant-pathogenic bacteria with agricultural importance. Those belonging to the 16SrII group, represented by 'Candidatus P. aurantifolia', have a wide range of plant hosts and cause significant yield losses in valuable crops, such as pear, sweet potato, peanut, and soybean. In this study, a method that combines immunoprecipitation-based enrichment and MinION long-read DNA sequencing was developed to solve the challenge of phytoplasma genome studies. This approach produced long reads with high mapping rates and high genomic coverage that can be combined with Illumina reads to produce complete genome assemblies with high accuracy. We applied this method to strain NCHU2014 and determined its complete genome sequence, which consists of one circular chromosome with 635,584 bp and one plasmid with 4,224 bp. Although 'Ca. P. aurantifolia' NCHU2014 has a small chromosome with only 471 protein-coding genes, it contains 33 transporter genes and 27 putative effector genes, which may contribute to obtaining nutrients from hosts and manipulating host developments for their survival and multiplication. Two effectors, the homologs of SAP11 and SAP54/PHYL1 identified in 'Ca. P. aurantifolia' NCHU2014, have the biochemical activities in destabilizing host transcription factors, which can explain the disease symptoms observed in infected plants. Taken together, this study provides the first complete genome available for the 16SrII phytoplasmas and contributes to the understanding of phytoplasma pathogenicity.
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Affiliation(s)
- Choon Meng Tan
- Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan
| | - Yu-Chen Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Jian-Rong Li
- Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung, Taiwan
| | - Yuan-Yu Chien
- Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan
| | - Chien-Jui Wang
- Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan
| | - Lin Chou
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Cheng-Wei Wang
- Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Ching Chiu
- Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan.,Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung, Taiwan
| | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.,Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung, Taiwan.,Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
| | - Jun-Yi Yang
- Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan.,Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung, Taiwan.,Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan.,Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
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20
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Furch ACU, Theißen G, Zimmermann MR. New phytoplasma effector: 50 shades of green. Cell Host Microbe 2021; 29:1601-1603. [PMID: 34762824 DOI: 10.1016/j.chom.2021.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Phytoplasmas are pathogenic bacteria that manipulate their plant hosts in dramatic ways. In issue 20 Vol. 184 of Cell, Huang and colleagues report on a phytoplasma effector protein that brings about manifold effects by a surprising mechanism. Are resistant plants on the horizon now?
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Affiliation(s)
- Alexandra C U Furch
- Plant Physiology, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Faculty of Biological Science, Friedrich Schiller University Jena, Jena, Germany.
| | - Günter Theißen
- Genetics, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Faculty of Biological Science, Friedrich Schiller University Jena, Jena, Germany
| | - Matthias R Zimmermann
- Plant Physiology, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Faculty of Biological Science, Friedrich Schiller University Jena, Jena, Germany
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21
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Huang W, MacLean AM, Sugio A, Maqbool A, Busscher M, Cho ST, Kamoun S, Kuo CH, Immink RGH, Hogenhout SA. Parasitic modulation of host development by ubiquitin-independent protein degradation. Cell 2021; 184:5201-5214.e12. [PMID: 34536345 DOI: 10.1016/j.cell.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/14/2021] [Accepted: 08/24/2021] [Indexed: 05/27/2023]
Abstract
Certain obligate parasites induce complex and substantial phenotypic changes in their hosts in ways that favor their transmission to other trophic levels. However, the mechanisms underlying these changes remain largely unknown. Here we demonstrate how SAP05 protein effectors from insect-vectored plant pathogenic phytoplasmas take control of several plant developmental processes. These effectors simultaneously prolong the host lifespan and induce witches' broom-like proliferations of leaf and sterile shoots, organs colonized by phytoplasmas and vectors. SAP05 acts by mediating the concurrent degradation of SPL and GATA developmental regulators via a process that relies on hijacking the plant ubiquitin receptor RPN10 independent of substrate ubiquitination. RPN10 is highly conserved among eukaryotes, but SAP05 does not bind insect vector RPN10. A two-amino-acid substitution within plant RPN10 generates a functional variant that is resistant to SAP05 activities. Therefore, one effector protein enables obligate parasitic phytoplasmas to induce a plethora of developmental phenotypes in their hosts.
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Affiliation(s)
- Weijie Huang
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Allyson M MacLean
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Akiko Sugio
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Abbas Maqbool
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Marco Busscher
- Laboratory of Molecular Biology, Wageningen University and Research, Wageningen 6708 PB, the Netherlands; Plant Developmental Systems, Bioscience, Wageningen University and Research, Wageningen 6708 PB, the Netherlands
| | - Shu-Ting Cho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Richard G H Immink
- Laboratory of Molecular Biology, Wageningen University and Research, Wageningen 6708 PB, the Netherlands; Plant Developmental Systems, Bioscience, Wageningen University and Research, Wageningen 6708 PB, the Netherlands
| | - Saskia A Hogenhout
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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22
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Huang W, MacLean AM, Sugio A, Maqbool A, Busscher M, Cho ST, Kamoun S, Kuo CH, Immink RGH, Hogenhout SA. Parasitic modulation of host development by ubiquitin-independent protein degradation. Cell 2021; 184:5201-5214.e12. [PMID: 34536345 PMCID: PMC8525514 DOI: 10.1016/j.cell.2021.08.029] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/14/2021] [Accepted: 08/24/2021] [Indexed: 01/08/2023]
Abstract
Certain obligate parasites induce complex and substantial phenotypic changes in their hosts in ways that favor their transmission to other trophic levels. However, the mechanisms underlying these changes remain largely unknown. Here we demonstrate how SAP05 protein effectors from insect-vectored plant pathogenic phytoplasmas take control of several plant developmental processes. These effectors simultaneously prolong the host lifespan and induce witches' broom-like proliferations of leaf and sterile shoots, organs colonized by phytoplasmas and vectors. SAP05 acts by mediating the concurrent degradation of SPL and GATA developmental regulators via a process that relies on hijacking the plant ubiquitin receptor RPN10 independent of substrate ubiquitination. RPN10 is highly conserved among eukaryotes, but SAP05 does not bind insect vector RPN10. A two-amino-acid substitution within plant RPN10 generates a functional variant that is resistant to SAP05 activities. Therefore, one effector protein enables obligate parasitic phytoplasmas to induce a plethora of developmental phenotypes in their hosts.
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Affiliation(s)
- Weijie Huang
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Allyson M MacLean
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Akiko Sugio
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Abbas Maqbool
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Marco Busscher
- Laboratory of Molecular Biology, Wageningen University and Research, Wageningen 6708 PB, the Netherlands; Plant Developmental Systems, Bioscience, Wageningen University and Research, Wageningen 6708 PB, the Netherlands
| | - Shu-Ting Cho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Richard G H Immink
- Laboratory of Molecular Biology, Wageningen University and Research, Wageningen 6708 PB, the Netherlands; Plant Developmental Systems, Bioscience, Wageningen University and Research, Wageningen 6708 PB, the Netherlands
| | - Saskia A Hogenhout
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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23
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Al-Subhi AM, Al-Sadi AM, Al-Yahyai RA, Chen Y, Mathers T, Orlovskis Z, Moro G, Mugford S, Al-Hashmi KS, Hogenhout SA. Witches' Broom Disease of Lime Contributes to Phytoplasma Epidemics and Attracts Insect Vectors. PLANT DISEASE 2021; 105:2637-2648. [PMID: 33349007 DOI: 10.1094/pdis-10-20-2112-re] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
An insect-transmitted phytoplasma causing Witches' Broom Disease of Lime (WBDL) is responsible for the drastic decline in lime production in several countries. However, it is unclear how WBDL phytoplasma (WBDLp) induces witches' broom symptoms and if these symptoms contribute to the spread of phytoplasma. Here we show that the gene encoding SAP11 of WBDLp (SAP11WBDL) is present in all WBDLp isolates collected from diseased trees. SAP11WBDL interacts with acid lime (Citrus aurantifolia) TCP transcription factors, specifically members of the TB1/CYC class that have a role in suppressing axillary branching in plants. Sampling of WBDLp-infected lime trees revealed that WBDLp titers and SAP11WBDL expression levels were higher in symptomatic leaves compared with asymptomatic sections of the same trees. Moreover, the witches' brooms were found to attract the vector leafhopper. Defense genes that have a role in plant defense responses to bacteria and insects are more downregulated in witches' brooms compared with asymptomatic sections of trees. These findings suggest that witches' broom-affected parts of the trees contribute to WBDL epidemics by supporting higher phytoplasma titers and attracting insect vectors.
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Affiliation(s)
- A M Al-Subhi
- Department of Plant Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, Al Khod 123, Oman
| | - A M Al-Sadi
- Department of Plant Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, Al Khod 123, Oman
| | - R A Al-Yahyai
- Department of Plant Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, Al Khod 123, Oman
| | - Y Chen
- John Innes Centre, Department of Crop Genetics, Norwich NR4 7UH, United Kingdom
| | - T Mathers
- John Innes Centre, Department of Crop Genetics, Norwich NR4 7UH, United Kingdom
| | - Z Orlovskis
- John Innes Centre, Department of Crop Genetics, Norwich NR4 7UH, United Kingdom
| | - G Moro
- John Innes Centre, Department of Crop Genetics, Norwich NR4 7UH, United Kingdom
| | - S Mugford
- John Innes Centre, Department of Crop Genetics, Norwich NR4 7UH, United Kingdom
| | - K S Al-Hashmi
- Department of Plant Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, Al Khod 123, Oman
| | - S A Hogenhout
- John Innes Centre, Department of Crop Genetics, Norwich NR4 7UH, United Kingdom
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24
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Wei H, Cheng Y, Sun Y, Zhang X, He H, Liu J. Genome-Wide Identification of the ARF Gene Family and ARF3 Target Genes Regulating Ovary Initiation in Hazel via ChIP Sequencing. FRONTIERS IN PLANT SCIENCE 2021; 12:715820. [PMID: 34447403 PMCID: PMC8382943 DOI: 10.3389/fpls.2021.715820] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Abstract
Hazel (Corylus spp.) is an economically important nut species with a unique biological characteristic of ovary differentiation and development initiating from the ovary primordium after pollination. Auxin participates in ovary initiation and has an essential impact on hazel fruit yield and quality. The regulation of auxin in ovary development is thought to be related to auxin response factors (ARFs); however, its detailed regulatory mechanism remains unclear. The spatiotemporal expression pattern of C. heterophylla ARF3 (ChARF3) was accessed via ARF gene family member identification and expression abundance analysis as well as immunohistochemistry. ChARF3 target genes were identified via chromatin immunoprecipitation followed by next-generation sequencing (ChIP-Seq). In total, 14 ChARF members containing at least B3 and Auxin_resp domains were found to be distributed on 9 of 11 chromosomes, and the protein molecular weights were predicted to range from 70.93-139.22 kD. Among eight differentially expressed ChARFs, ChARF3 showed the most significant differences over four ovary developmental stages. Immunohistochemical analysis revealed that ChARF3 was expressed in the ovary primordium and funiculus, integument, endosperm, radicle, and cotyledon indicating its potential regulatory roles in ovary differentiation and development. In total, 3,167 ChARF3 target genes were identified through ChIP-Seq in four ovary developmental stages and were significantly enriched in the biosynthesis of secondary metabolites (ko01110), phenylpropanoid biosynthesis (ko00940), and phytohormone signal transduction (ko04075). ChARF3 was hypothesized to be involved in the regulation of auxin-induced genes and the transcription factors MADS, AP2/ERF, TCP, FT, and LFY. These results suggest that ChARF3 may regulate ovary initiation and ovule development by mediating genes related to auxin biosynthesis and transport, cell division and proliferation, and flower and fruit development. This study provides new insights into the molecular mechanism of hazel yield formation.
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Affiliation(s)
| | | | | | | | | | - Jianfeng Liu
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping, China
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25
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Garcion C, Béven L, Foissac X. Comparison of Current Methods for Signal Peptide Prediction in Phytoplasmas. Front Microbiol 2021; 12:661524. [PMID: 33841387 PMCID: PMC8026896 DOI: 10.3389/fmicb.2021.661524] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/02/2021] [Indexed: 11/13/2022] Open
Abstract
Although phytoplasma studies are still hampered by the lack of axenic cultivation methods, the availability of genome sequences allowed dramatic advances in the characterization of the virulence mechanisms deployed by phytoplasmas, and highlighted the detection of signal peptides as a crucial step to identify effectors secreted by phytoplasmas. However, various signal peptide prediction methods have been used to mine phytoplasma genomes, and no general evaluation of these methods is available so far for phytoplasma sequences. In this work, we compared the prediction performance of SignalP versions 3.0, 4.0, 4.1, 5.0 and Phobius on several sequence datasets originating from all deposited phytoplasma sequences. SignalP 4.1 with specific parameters showed the most exhaustive and consistent prediction ability. However, the configuration of SignalP 4.1 for increased sensitivity induced a much higher rate of false positives on transmembrane domains located at N-terminus. Moreover, sensitive signal peptide predictions could similarly be achieved by the transmembrane domain prediction ability of TMHMM and Phobius, due to the relatedness between signal peptides and transmembrane regions. Beyond the results presented herein, the datasets assembled in this study form a valuable benchmark to compare and evaluate signal peptide predictors in a field where experimental evidence of secretion is scarce. Additionally, this study illustrates the utility of comparative genomics to strengthen confidence in bioinformatic predictions.
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Affiliation(s)
- Christophe Garcion
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Villenave d'Ornon, France
| | - Laure Béven
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Villenave d'Ornon, France
| | - Xavier Foissac
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Villenave d'Ornon, France
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26
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Xue C, Liu Z, Wang L, Li H, Gao W, Liu M, Zhao Z, Zhao J. The antioxidant defense system in Chinese jujube is triggered to cope with phytoplasma invasion. TREE PHYSIOLOGY 2020; 40:1437-1449. [PMID: 32483619 DOI: 10.1093/treephys/tpaa067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 04/18/2020] [Accepted: 05/27/2020] [Indexed: 05/27/2023]
Abstract
Reactive oxygen species (ROS) in plants increase dramatically under pathogen attack, and the antioxidant defense system is then triggered to protect the plant against the ROS. Jujube witches' broom disease (JWB), caused by phytoplasma, is a destructive disease of Chinese jujube. The results of fluorescence-based measurement revealed that ROS were overproduced within jujube leaves after phytoplasma invasion. Furthermore, analysis based on mRNA and metabolite levels revealed that ascorbic acid (AsA) metabolism was strengthened under phytoplasma stress. The high expression of genes involved in the AsA/glutathione (GSH) cycle and thioredoxin (Trx) synthesis in diseased leaves indicated that GSH and Trx actively respond to phytoplasma infection. Moreover, higher activities of enzymatic antioxidants and the upregulated expression of related genes were confirmed in diseased tissues. Both nonenzymatic and enzymatic antioxidants in the host jujube were strongly stimulated to cope with ROS caused by phytoplasma stress. Compared with that in the susceptible variety, the activities of glutathione S-transferase and peroxidase in the resistant variety at the earlier infection stage were higher, indicating that enzymes might be involved in the resistance to phytoplasma. These results highlight the roles of the antioxidant defense system of the host plant in the tolerance to phytoplasma invasion.
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Affiliation(s)
- Chaoling Xue
- College of Life Science, Hebei Agricultural University, Baoding 071000, China
- Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, Hebei Agricultural University, Baoding 071000, China
| | - Zhiguo Liu
- Research Center of Chinese Jujube, Hebei Agricultural University, Baoding 071000, China
| | - Lihu Wang
- College of Landscape and Ecological Engineering, Hebei University of Engineering, Handan 056038, China
| | - Hongtai Li
- College of Life Science, Hebei Agricultural University, Baoding 071000, China
- Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, Hebei Agricultural University, Baoding 071000, China
| | - Weilin Gao
- College of Life Science, Hebei Agricultural University, Baoding 071000, China
- Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, Hebei Agricultural University, Baoding 071000, China
| | - Mengjun Liu
- Research Center of Chinese Jujube, Hebei Agricultural University, Baoding 071000, China
| | - Zhihui Zhao
- Research Center of Chinese Jujube, Hebei Agricultural University, Baoding 071000, China
| | - Jin Zhao
- College of Life Science, Hebei Agricultural University, Baoding 071000, China
- Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, Hebei Agricultural University, Baoding 071000, China
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27
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Huang W, Reyes-Caldas P, Mann M, Seifbarghi S, Kahn A, Almeida RPP, Béven L, Heck M, Hogenhout SA, Coaker G. Bacterial Vector-Borne Plant Diseases: Unanswered Questions and Future Directions. MOLECULAR PLANT 2020; 13:1379-1393. [PMID: 32835885 PMCID: PMC7769051 DOI: 10.1016/j.molp.2020.08.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/18/2020] [Accepted: 08/18/2020] [Indexed: 06/01/2023]
Abstract
Vector-borne plant diseases have significant ecological and economic impacts, affecting farm profitability and forest composition throughout the world. Bacterial vector-borne pathogens have evolved sophisticated strategies to interact with their hemipteran insect vectors and plant hosts. These pathogens reside in plant vascular tissue, and their study represents an excellent opportunity to uncover novel biological mechanisms regulating intracellular pathogenesis and to contribute to the control of some of the world's most invasive emerging diseases. In this perspective, we highlight recent advances and major unanswered questions in the realm of bacterial vector-borne disease, focusing on liberibacters, phytoplasmas, spiroplasmas, and Xylella fastidiosa.
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Affiliation(s)
- Weijie Huang
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Paola Reyes-Caldas
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA
| | - Marina Mann
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853, USA
| | - Shirin Seifbarghi
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA
| | - Alexandra Kahn
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720, USA
| | - Rodrigo P P Almeida
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720, USA
| | - Laure Béven
- UMR 1332 Biologie du Fruit et Pathologie, Univ. Bordeaux, INRAE, Villenave d'Ornon 33882 France
| | - Michelle Heck
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853, USA; Boyce Thompson Institute, Ithaca, NY 14853, USA; Emerging Pests and Pathogens Research Unit, Robert W. Holley Center, USDA ARS, Ithaca, NY 14853, USA
| | - Saskia A Hogenhout
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK; School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Gitta Coaker
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA.
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28
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Iwabuchi N, Kitazawa Y, Maejima K, Koinuma H, Miyazaki A, Matsumoto O, Suzuki T, Nijo T, Oshima K, Namba S, Yamaji Y. Functional variation in phyllogen, a phyllody-inducing phytoplasma effector family, attributable to a single amino acid polymorphism. MOLECULAR PLANT PATHOLOGY 2020; 21:1322-1336. [PMID: 32813310 PMCID: PMC7488466 DOI: 10.1111/mpp.12981] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/25/2020] [Accepted: 07/05/2020] [Indexed: 05/08/2023]
Abstract
Flower malformation represented by phyllody is a common symptom of phytoplasma infection induced by a novel family of phytoplasma effectors called phyllogens. Despite the accumulation of functional and structural phyllogen information, the molecular mechanisms of phyllody have not yet been integrated with their evolutionary aspects due to the limited data on their homologs across diverse phytoplasma lineages. Here, we developed a novel universal PCR-based approach to identify 25 phytoplasma phyllogens related to nine "Candidatus Phytoplasma" species, including four species whose phyllogens have not yet been identified. Phylogenetic analyses showed that the phyllogen family consists of four groups (phyl-A, -B, -C, and -D) and that the evolutionary relationships of phyllogens were significantly distinct from those of phytoplasmas, suggesting that phyllogens were transferred horizontally among phytoplasma strains and species. Although phyllogens belonging to the phyl-A, -C, and -D groups induced phyllody, the phyl-B group lacked the ability to induce phyllody. Comparative functional analyses of phyllogens revealed that a single amino acid polymorphism in phyl-B group phyllogens prevented interactions between phyllogens and A- and E-class MADS domain transcription factors (MTFs), resulting in the inability to degrade several MTFs and induce phyllody. Our finding of natural variation in the function of phytoplasma effectors provides new insights into molecular mechanisms underlying the aetiology of phytoplasma diseases.
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Affiliation(s)
- Nozomu Iwabuchi
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Yugo Kitazawa
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Kensaku Maejima
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Hiroaki Koinuma
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Akio Miyazaki
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Ouki Matsumoto
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Takumi Suzuki
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Takamichi Nijo
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | | | - Shigetou Namba
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
| | - Yasuyuki Yamaji
- Department of Agricultural and Environmental BiologyGraduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
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29
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Aurin MB, Haupt M, Görlach M, Rümpler F, Theißen G. Structural Requirements of the Phytoplasma Effector Protein SAP54 for Causing Homeotic Transformation of Floral Organs. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:1129-1141. [PMID: 32689871 DOI: 10.1094/mpmi-02-20-0028-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Phytoplasmas are intracellular bacterial plant pathogens that cause devastating diseases in crops and ornamental plants by the secretion of effector proteins. One of these effector proteins, termed SECRETED ASTER YELLOWS WITCHES' BROOM PROTEIN 54 (SAP54), leads to the degradation of a specific subset of floral homeotic proteins of the MIKC-type MADS-domain family via the ubiquitin-proteasome pathway. In consequence, the developing flowers show the homeotic transformation of floral organs into vegetative leaf-like structures. The molecular mechanism of SAP54 action involves binding to the keratin-like domain of MIKC-type proteins and to some RAD23 proteins, which translocate ubiquitylated substrates to the proteasome. The structural requirements and specificity of SAP54 function are poorly understood, however. Here, we report, based on biophysical and molecular biological analyses, that SAP54 folds into an α-helical structure. Insertion of helix-breaking mutations disrupts correct folding of SAP54 and compromises SAP54 binding to its target proteins and, concomitantly, its ability to evoke disease phenotypes in vivo. Interestingly, dynamic light scattering data together with electrophoretic mobility shift assays suggest that SAP54 preferentially binds to multimeric complexes of MIKC-type proteins rather than to dimers or monomers of these proteins. Together with data from literature, this finding suggests that MIKC-type proteins and SAP54 constitute multimeric α-helical coiled coils. Our investigations clarify the structure-function relationship of an important phytoplasma effector protein and may thus ultimately help to develop treatments against some devastating plant diseases.
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Affiliation(s)
- Marc-Benjamin Aurin
- Matthias Schleiden Institute / Genetics, Friedrich Schiller University Jena, Philosophenweg 12, 07743 Jena, Germany
| | - Michael Haupt
- Matthias Schleiden Institute / Genetics, Friedrich Schiller University Jena, Philosophenweg 12, 07743 Jena, Germany
| | - Matthias Görlach
- Leibniz Institute on Aging - Fritz Lipmann Institute, Beutenbergstr. 11, 07745 Jena, Germany
| | - Florian Rümpler
- Matthias Schleiden Institute / Genetics, Friedrich Schiller University Jena, Philosophenweg 12, 07743 Jena, Germany
| | - Günter Theißen
- Matthias Schleiden Institute / Genetics, Friedrich Schiller University Jena, Philosophenweg 12, 07743 Jena, Germany
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Cho ST, Kung HJ, Huang W, Hogenhout SA, Kuo CH. Species Boundaries and Molecular Markers for the Classification of 16SrI Phytoplasmas Inferred by Genome Analysis. Front Microbiol 2020; 11:1531. [PMID: 32754131 PMCID: PMC7366425 DOI: 10.3389/fmicb.2020.01531] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 06/12/2020] [Indexed: 11/29/2022] Open
Abstract
Phytoplasmas are plant-pathogenic bacteria that impact agriculture worldwide. The commonly adopted classification system for phytoplasmas is based on the restriction fragment length polymorphism (RFLP) analysis of their 16S rRNA genes. With the increased availability of phytoplasma genome sequences, the classification system can now be refined. This work examined 11 strains in the 16SrI group within the genus ‘Candidatus Phytoplasma’ and investigated the possible species boundaries. We confirmed that the RFLP classification method is problematic due to intragenomic variation of the 16S rRNA genes and uneven weighing of different nucleotide positions. Importantly, our results based on the molecular phylogeny, differentiations in chromosomal segments and gene content, and divergence in homologous sequences, all supported that these strains may be classified into multiple operational taxonomic units (OTUs) equivalent to species. Strains assigned to the same OTU share >97% genome-wide average nucleotide identity (ANI) and >78% of their protein-coding genes. In comparison, strains assigned to different OTUs share < 94% ANI and < 75% of their genes. Reduction in homologous recombination between OTUs is one possible explanation for the discontinuity in genome similarities, and these findings supported the proposal that 95% ANI could serve as a cutoff for distinguishing species in bacteria. Additionally, critical examination of these results and the raw sequencing reads led to the identification of one genome that was presumably mis-assembled by combining two sequencing libraries built from phytoplasmas belonging to different OTUs. This finding provided a cautionary tale for working on uncultivated bacteria. Based on the new understanding of phytoplasma divergence and the current genome availability, we developed five molecular markers that could be used for multilocus sequence analysis (MLSA). By selecting markers that are short yet highly informative, and are distributed evenly across the chromosome, these markers provided a cost-effective system that is robust against recombination. Finally, examination of the effector gene distribution further confirmed the rapid gains and losses of these genes, as well as the involvement of potential mobile units (PMUs) in their molecular evolution. Future improvements on the taxon sampling of phytoplasma genomes will allow further expansions of similar analysis, and thus contribute to phytoplasma taxonomy and diagnostics.
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Affiliation(s)
- Shu-Ting Cho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Hung-Jui Kung
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Weijie Huang
- Department of Crop Genetics, John Innes Centre, Norwich, United Kingdom
| | | | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
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Ma F, Huang J, Yang J, Zhou J, Sun Q, Sun J. Identification, expression and miRNA targeting of auxin response factor genes related to phyllody in the witches’ broom disease of jujube. Gene 2020; 746:144656. [DOI: 10.1016/j.gene.2020.144656] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 04/04/2020] [Accepted: 04/06/2020] [Indexed: 11/16/2022]
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Cao Y, Trivellone V, Dietrich CH. A timetree for phytoplasmas (Mollicutes) with new insights on patterns of evolution and diversification. Mol Phylogenet Evol 2020; 149:106826. [PMID: 32283136 DOI: 10.1016/j.ympev.2020.106826] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 02/12/2020] [Accepted: 04/07/2020] [Indexed: 11/16/2022]
Abstract
The first comprehensive timetree is presented for phytoplasmas, a diverse group of obligate intracellular bacteria restricted to phloem sieve elements of vascular plants and tissues of their hemipteran insect vectors. Maximum likelihood-based phylogenetic analysis of DNA sequence data from the 16S rRNA and methionine aminopeptidase (map) genes yielded well resolved estimates of phylogenetic relationships among major phytoplasma lineages, 16Sr groups and known strains of phytoplasmas. Age estimates for divergences among two major lineages of Mollicutes based on a previous comprehensive bacterial timetree were used to calibrate an initial 16S timetree. A separate timetree was estimated based on the more rapidly-evolving map gene, with an internal calibration based on a recent divergence within two related 16Sr phytoplasma subgroups in group 16SrV thought to have been driven by the introduction of the North American leafhopper vector Scaphoideus titanus Ball into Europe during the early part of the 20th century. Combining the resulting divergence time estimates into a final 16S timetree suggests that evolutionary rates have remained relatively constant overall through the evolution of phytoplasmas and that the origin of this lineage, at ~641 million years ago (Ma), preceded the origin of land plants and hemipteran insects. Nevertheless, the crown group of phytoplasmas is estimated to have begun diversifying ~316 Ma, roughly coinciding with the origin of seed plants and Hemiptera. Some phytoplasma groups apparently associated with particular plant families or insect vector lineages generally arose more recently than their respective hosts and vectors, suggesting that vector-mediated host shifts have been an important mechanism in the evolutionary diversification of phytoplasmas. Further progress in understanding macroevolutionary patterns in phytoplasmas is hindered by large gaps in knowledge of the identity of competent vectors and lack of data on phytoplasma associations with non-economically important plants.
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Affiliation(s)
- Yanghui Cao
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Champaign, IL 61820, USA
| | - Valeria Trivellone
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Champaign, IL 61820, USA.
| | - Christopher H Dietrich
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Champaign, IL 61820, USA
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Singh A, Lakhanpaul S. Detection, characterization and evolutionary aspects of S54LP of SP (SAP54 Like Protein of Sesame Phyllody): a phytoplasma effector molecule associated with phyllody development in sesame ( Sesamum indicum L.). PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2020; 26:445-458. [PMID: 32205922 PMCID: PMC7078397 DOI: 10.1007/s12298-020-00764-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 12/24/2019] [Accepted: 01/14/2020] [Indexed: 05/05/2023]
Abstract
SAP54, an effector protein secreted by phytoplasmas has been reported to induce phyllody. S54LP of SP (SAP54 Like Protein of Sesame Phyllody), a SAP54 ortholog from phyllody and witches' broom affected sesame (Sesamum indicum L.) was amplified, cloned and sequenced. Comparative sequence and phylogenetic analysis of diverse phytoplasma strains was carried out to delineate the evolution of S54LP of SP. The degree of polymorphism across SAP54 orthologs and the evolutionary forces acting on this effector protein were ascertained. Site-specific selection across SAP54 orthologs was estimated using Fixed Effects Likelihood (FEL) approach. Nonsynonymous substitutions were detected in the SAP54 orthologs' sequences from phytoplasmas belonging to same (sub) group. Phylogenetic analysis based on S54LP of SP grouped phytoplasmas belonging to same 16SrDNA (sub) groups into different clusters. Analysis of selection forces acting on SAP54 orthologs from nine different phytoplasma (sub)groups, affecting plant species belonging to twelve different families across ten countries showed the orthologs to be under purifying (negative) selection. One amino acid residue was found to be under pervasive diversifying (positive) selection and a total of three amino acid sites were found to be under pervasive purifying (negative) selection. The location of these amino acids in the signal peptide and mature protein was studied with an aim to understand their role in protein-protein interaction. Asparagine residues (at positions 68 and 84) were found to be under pervasive purifying selection suggesting their functional importance in the effector protein. Our study suggests lack of coevolution between SAP54 and 16SrDNA. Signal peptide appears to evolve at a rate slightly higher than the mature protein. Overall, SAP54 and its orthologs are evolving under purifying selection confirming their functional importance in phytoplasma virulence.
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Affiliation(s)
- Amrita Singh
- Department of Botany, University of Delhi, Delhi, 110007 India
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Liao YT, Lin SS, Lin SJ, Sun WT, Shen BN, Cheng HP, Lin CP, Ko TP, Chen YF, Wang HC. Structural insights into the interaction between phytoplasmal effector causing phyllody 1 and MADS transcription factors. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:706-719. [PMID: 31323156 DOI: 10.1111/tpj.14463] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 05/24/2019] [Accepted: 07/02/2019] [Indexed: 05/21/2023]
Abstract
Phytoplasmas are bacterial plant pathogens which can induce severe symptoms including dwarfism, phyllody and virescence in an infected plant. Because phytoplasmas infect many important crops such as peanut and papaya they have caused serious agricultural losses. The phytoplasmal effector causing phyllody 1 (PHYL1) is an important phytoplasmal pathogenic factor which affects the biological function of MADS transcription factors by interacting with their K (keratin-like) domain, thus resulting in abnormal plant developments such as phyllody. Until now, lack of information on the structure of PHYL1 has prevented a detailed understanding of the binding mechanism between PHYL1 and the MADS transcription factors. Here, we present the crystal structure of PHYL1 from peanut witches'-broom phytoplasma (PHYL1PnWB ). This protein was found to fold into a unique α-helical hairpin with exposed hydrophobic residues on its surface that may play an important role in its biological function. Using proteomics approaches, we propose a binding mode of PHYL1PnWB with the K domain of the MADS transcription factor SEPALLATA3 (SEP3_K) and identify the residues of PHYL1PnWB that are important for this interaction. Furthermore, using surface plasmon resonance we measure the binding strength of PHYL1PnWB proteins to SEP3_K. Lastly, based on confocal images, we found that α-helix 2 of PHYL1PnWB plays an important role in PHYL1-mediated degradation of SEP3. Taken together, these results provide a structural understanding of the specific binding mechanism between PHYL1PnWB and SEP3_K.
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Affiliation(s)
- Yi-Ting Liao
- The PhD Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei 11529, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan
| | - Shih-Shun Lin
- Institute of Biotechnology, National Taiwan University, Taipei 10617, Taiwan
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan
- Center of Biotechnology, National Taiwan University, Taipei 10617, Taiwan
| | - Shin-Jen Lin
- Department of Biotechnology and Bioindustry Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan
| | - Wan-Ting Sun
- Institute of Biotechnology, National Taiwan University, Taipei 10617, Taiwan
- Department of Plant Pathology and Microbiology, College of Bioresources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Bing-Nan Shen
- Institute of Biotechnology, National Taiwan University, Taipei 10617, Taiwan
- Department of Plant Pathology and Microbiology, College of Bioresources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Han-Pin Cheng
- Institute of Biotechnology, National Taiwan University, Taipei 10617, Taiwan
- Department of Plant Pathology and Microbiology, College of Bioresources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Chan-Pin Lin
- Institute of Biotechnology, National Taiwan University, Taipei 10617, Taiwan
- Department of Plant Pathology and Microbiology, College of Bioresources and Agriculture, National Taiwan University, Taipei 10617, Taiwan
| | - Tzu-Ping Ko
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Yi-Fan Chen
- The PhD Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei 11529, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan
| | - Hao-Ching Wang
- The PhD Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei 11529, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan
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Wei W, Davis RE, Bauchan GR, Zhao Y. New Symptoms Identified in Phytoplasma-Infected Plants Reveal Extra Stages of Pathogen-Induced Meristem Fate-Derailment. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:1314-1323. [PMID: 31120802 DOI: 10.1094/mpmi-01-19-0035-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In flowering plants, the transition of a shoot apical meristem from vegetative to reproductive destiny is a graduated, multistage process that involves sequential conversion of the vegetative meristem to an inflorescence meristem, initiation of floral meristems, emergence of flower organ primordia, and formation of floral organs. This orderly process can be derailed by phytoplasma, a bacterium that parasitizes phloem sieve cells. In a previous study, we showed that phytoplasma-induced malformation of flowers reflects stage-specific derailment of shoot apical meristems from their genetically preprogrammed reproductive destiny. Our current study unveiled new symptoms of abnormal morphogenesis, pointing to derailment of meristem transition at additional stages previously unidentified. We also found that the fate of developing meristems may be derailed even after normal termination of the floral meristem and onset of seed production. Although previous reports by others have indicated that different symptoms may be induced by different phytoplasmal effectors, the phenomenon observed in our experiment raises interesting questions as to (i) whether effectors can act at specific stages of meristem transition and (ii) whether specific floral abnormalities are attributable to meristem fate-derailment events triggered by different effectors that each act at a specific stage in meristem transition. Research addressing such questions may lead to discoveries of an array of phytoplasmal effectors.
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Affiliation(s)
- Wei Wei
- Molecular Plant Pathology Laboratory, Beltsville Agricultural Research Center, United States Department of Agriculture-Agricultural Research Service, Beltsville, MD, U.S.A
| | - Robert E Davis
- Molecular Plant Pathology Laboratory, Beltsville Agricultural Research Center, United States Department of Agriculture-Agricultural Research Service, Beltsville, MD, U.S.A
| | - Gary R Bauchan
- Electron and Confocal Microscopy Unit, Soybean Genomics and Improvement Laboratory, Beltsville Agricultural Research Center
| | - Yan Zhao
- Molecular Plant Pathology Laboratory, Beltsville Agricultural Research Center, United States Department of Agriculture-Agricultural Research Service, Beltsville, MD, U.S.A
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Pecher P, Moro G, Canale MC, Capdevielle S, Singh A, MacLean A, Sugio A, Kuo CH, Lopes JRS, Hogenhout SA. Phytoplasma SAP11 effector destabilization of TCP transcription factors differentially impact development and defence of Arabidopsis versus maize. PLoS Pathog 2019; 15:e1008035. [PMID: 31557268 PMCID: PMC6802841 DOI: 10.1371/journal.ppat.1008035] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 10/21/2019] [Accepted: 08/20/2019] [Indexed: 12/13/2022] Open
Abstract
Phytoplasmas are insect-transmitted bacterial pathogens that colonize a wide range of plant species, including vegetable and cereal crops, and herbaceous and woody ornamentals. Phytoplasma-infected plants often show dramatic symptoms, including proliferation of shoots (witch's brooms), changes in leaf shapes and production of green sterile flowers (phyllody). Aster Yellows phytoplasma Witches' Broom (AY-WB) infects dicots and its effector, secreted AYWB protein 11 (SAP11), was shown to be responsible for the induction of shoot proliferation and leaf shape changes of plants. SAP11 acts by destabilizing TEOSINTE BRANCHED 1-CYCLOIDEA-PROLIFERATING CELL FACTOR (TCP) transcription factors, particularly the class II TCPs of the CYCLOIDEA/TEOSINTE BRANCHED 1 (CYC/TB1) and CINCINNATA (CIN)-TCP clades. SAP11 homologs are also present in phytoplasmas that cause economic yield losses in monocot crops, such as maize, wheat and coconut. Here we show that a SAP11 homolog of Maize Bushy Stunt Phytoplasma (MBSP), which has a range primarily restricted to maize, destabilizes specifically TB1/CYC TCPs. SAP11MBSP and SAP11AYWB both induce axillary branching and SAP11AYWB also alters leaf development of Arabidopsis thaliana and maize. However, only in maize, SAP11MBSP prevents female inflorescence development, phenocopying maize tb1 lines, whereas SAP11AYWB prevents male inflorescence development and induces feminization of tassels. SAP11AYWB promotes fecundity of the AY-WB leafhopper vector on A. thaliana and modulates the expression of A. thaliana leaf defence response genes that are induced by this leafhopper, in contrast to SAP11MBSP. Neither of the SAP11 effectors promote fecundity of AY-WB and MBSP leafhopper vectors on maize. These data provide evidence that class II TCPs have overlapping but also distinct roles in regulating development and defence in a dicot and a monocot plant species that is likely to shape SAP11 effector evolution depending on the phytoplasma host range.
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Affiliation(s)
- Pascal Pecher
- John Innes Centre, Department of Crop Genetics, Norwich Research Park, Norwich, United Kingdom
| | - Gabriele Moro
- John Innes Centre, Department of Crop Genetics, Norwich Research Park, Norwich, United Kingdom
| | - Maria Cristina Canale
- John Innes Centre, Department of Crop Genetics, Norwich Research Park, Norwich, United Kingdom
- Luiz de Queiroz College of Agriculture, Department of Entomology and Acarology, University of São Paulo, Piracicaba, Brazil
| | - Sylvain Capdevielle
- John Innes Centre, Department of Crop Genetics, Norwich Research Park, Norwich, United Kingdom
| | - Archana Singh
- John Innes Centre, Department of Crop Genetics, Norwich Research Park, Norwich, United Kingdom
| | - Allyson MacLean
- John Innes Centre, Department of Crop Genetics, Norwich Research Park, Norwich, United Kingdom
| | - Akiko Sugio
- John Innes Centre, Department of Crop Genetics, Norwich Research Park, Norwich, United Kingdom
| | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Joao R. S. Lopes
- Luiz de Queiroz College of Agriculture, Department of Entomology and Acarology, University of São Paulo, Piracicaba, Brazil
| | - Saskia A. Hogenhout
- John Innes Centre, Department of Crop Genetics, Norwich Research Park, Norwich, United Kingdom
- * E-mail:
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Cho ST, Lin CP, Kuo CH. Genomic Characterization of the Periwinkle Leaf Yellowing (PLY) Phytoplasmas in Taiwan. Front Microbiol 2019; 10:2194. [PMID: 31608032 PMCID: PMC6761752 DOI: 10.3389/fmicb.2019.02194] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 09/06/2019] [Indexed: 12/17/2022] Open
Abstract
The periwinkle leaf yellowing (PLY) disease was first reported in Taiwan in 2005. This disease was caused by an uncultivated bacterium in the genus “Candidatus phytoplasma.” In subsequent years, this bacterium was linked to other plant diseases and caused losses in agriculture. For genomic investigation of this bacterium and its relatives, we conducted whole genome sequencing of a PLY phytoplasma from an infected periwinkle collected in Taoyuan. The de novo genome assembly produced eight contigs with a total length of 824,596 bp. The annotation contains 775 protein-coding genes, 63 pseudogenes, 32 tRNA genes, and two sets of rRNA operons. To characterize the genomic diversity across populations, a second strain that infects green onions in Yilan was collected for re-sequencing analysis. Comparison between these two strains identified 337 sequence polymorphisms and 10 structural variations. The metabolic pathway analysis indicated that the PLY phytoplasma genome contains two regions with highly conserved gene composition for carbohydrate metabolism. Intriguingly, each region contains several pseudogenes and the remaining functional genes in these two regions complement each other, suggesting a case of duplication followed by differential gene losses. Comparative analysis with other available phytoplasma genomes indicated that this PLY phytoplasma belongs to the 16SrI-B subgroup in the genus, with “Candidatus Phytoplasma asteris” that causes the onion yellowing (OY) disease in Japan as the closest known relative. For characterized effectors that these bacteria use to manipulate their plant hosts, the PLY phytoplasma has homologs for SAP11, SAP54/PHYL1, and TENGU. For genome structure comparison, we found that potential mobile unit (PMU) insertions may be the main factor that drives genome rearrangements in these bacteria. A total of 10 PMU-like regions were found in the PLY phytoplasma genome. Two of these PMUs were found to harbor one SAP11 homolog each, with one more similar to the 16SrI-B type and the other more similar to the 16SrI-A type, suggesting possible horizontal transfer. Taken together, this work provided a first look into population genomics of the PLY phytoplasmas in Taiwan, as well as identified several evolutionary processes that contributed to the genetic diversification of these plant-pathogenic bacteria.
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Affiliation(s)
- Shu-Ting Cho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Chan-Pin Lin
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, Taiwan
| | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
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Crystal structure of phyllogen, a phyllody-inducing effector protein of phytoplasma. Biochem Biophys Res Commun 2019; 513:952-957. [PMID: 31010685 DOI: 10.1016/j.bbrc.2019.04.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 04/08/2019] [Indexed: 11/20/2022]
Abstract
Phytoplasmas are plant pathogenic bacteria that often induce unique phyllody symptoms in which the floral organs are transformed into leaf-like structures. Recently, a novel family of bacterial effector genes, called phyllody-inducing genes (phyllogens), was identified as being involved in the induction of phyllody by degrading floral MADS-domain transcription factors (MTFs). However, the structural characteristics of phyllogens are unknown. In this study, we elucidated the crystal structure of PHYL1OY, a phyllogen of 'Candidatus Phytoplasma asteris' onion yellows strain, at a resolution of 2.4 Å. The structure of PHYL1 consisted of two α-helices connected by a random loop in a coiled-coil manner. In both α-helices, the distributions of hydrophobic residues were conserved among phyllogens. Amino acid insertion mutations into either α-helix resulted in the loss of phyllody-inducing activity and the ability of the phyllogen to degrade floral MTF. In contrast, the same insertion in the loop region did not affect either activity, indicating that both conserved α-helices are important for the function of phyllogens. This is the first report on the crystal structure of an effector protein of phytoplasmas.
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NAMBA S. Molecular and biological properties of phytoplasmas. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2019; 95:401-418. [PMID: 31406061 PMCID: PMC6766451 DOI: 10.2183/pjab.95.028] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Phytoplasmas, a large group of plant-pathogenic, phloem-inhabiting bacteria were discovered by Japanese scientists in 1967. They are transmitted from plant to plant by phloem-feeding insect hosts and cause a variety of symptoms and considerable damage in more than 1,000 plant species. In the first quarter century following the discovery of phytoplasmas, their tiny cell size and the difficulty in culturing them hampered their biological classification and restricted research to ecological studies such as detection by electron microscopy and identification of insect vectors. In the 1990s, however, tremendous advances in molecular biology and related technologies encouraged investigation of phytoplasmas at the molecular level. In the last quarter century, molecular biology has revealed important properties of phytoplasmas. This review summarizes the history and current status of phytoplasma research, focusing on their discovery, molecular classification, diagnosis of phytoplasma diseases, reductive evolution of their genomes, characteristic features of their plasmids, molecular mechanisms of insect transmission, virulence factors, and chemotherapy.
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Affiliation(s)
- Shigetou NAMBA
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Correspondence should be addressed: S. Namba, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan (e-mail: )
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Wang N, Yang H, Yin Z, Liu W, Sun L, Wu Y. Phytoplasma effector SWP1 induces witches' broom symptom by destabilizing the TCP transcription factor BRANCHED1. MOLECULAR PLANT PATHOLOGY 2018; 19:2623-2634. [PMID: 30047227 PMCID: PMC6638060 DOI: 10.1111/mpp.12733] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 06/28/2018] [Accepted: 07/21/2018] [Indexed: 05/18/2023]
Abstract
Phytoplasmas are insect-transmitted phytopathogenic bacteria, which secrete effector proteins that are often responsible for altering the plant morphology and behaviours of their vectors. Phytoplasma multifunctional effector proteins TENGU and SAP11 induce typical witches' broom symptoms, but their mode of action remains unknown. Previously, we have identified a SAP11-like effector from wheat blue dwarf phytoplasma, SWP1, which induces witches' broom symptoms in Nicotiana benthamiana. In this study, we observed that SWP1-expressing transgenic Arabidopsis thaliana plants showed typical witches' broom symptoms. On overexpression of SWP1 truncation mutants in N. benthamiana, we identified that the coiled-coil domain and nuclear localization were responsible for the induction of witches' broom symptoms. In addition, using yeast two-hybrid and bimolecular fluorescence complementation assays, we demonstrated that SWP1 interacts with A. thaliana transcription factor TCP18 (BRC1), the key negative regulator of branching signals in various plant species. Moreover, in planta co-expression analysis showed that SWP1 promotes the degradation of BRC1 via a proteasome system. These findings suggest that the phytoplasma effector SWP1 induces witches' broom symptoms through targeting of BRC1 and promoting its degradation.
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Affiliation(s)
- Nan Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYangling712100China
| | - Haizhen Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYangling712100China
| | - Zhiyuan Yin
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYangling712100China
| | - Wenting Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYangling712100China
| | - Liying Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYangling712100China
| | - Yunfeng Wu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant ProtectionNorthwest A&F UniversityYangling712100China
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41
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Tomkins M, Kliot A, Marée AF, Hogenhout SA. A multi-layered mechanistic modelling approach to understand how effector genes extend beyond phytoplasma to modulate plant hosts, insect vectors and the environment. CURRENT OPINION IN PLANT BIOLOGY 2018; 44:39-48. [PMID: 29547737 DOI: 10.1016/j.pbi.2018.02.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/05/2018] [Accepted: 02/06/2018] [Indexed: 05/13/2023]
Abstract
Members of the Candidatus genus Phytoplasma are small bacterial pathogens that hijack their plant hosts via the secretion of virulence proteins (effectors) leading to a fascinating array of plant phenotypes, such as witch's brooms (stem proliferations) and phyllody (retrograde development of flowers into vegetative tissues). Phytoplasma depend on insect vectors for transmission, and interestingly, these insect vectors were found to be (in)directly attracted to plants with these phenotypes. Therefore, phytoplasma effectors appear to reprogram plant development and defence to lure insect vectors, similarly to social engineering malware, which employs tricks to lure people to infected computers and webpages. A multi-layered mechanistic modelling approach will enable a better understanding of how phytoplasma effector-mediated modulations of plant host development and insect vector behaviour contribute to phytoplasma spread, and ultimately to predict the long reach of phytoplasma effector genes.
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Affiliation(s)
- Melissa Tomkins
- Department of Computational and Systems Biology, The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Adi Kliot
- Department of Crop Genetics, The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Athanasius Fm Marée
- Department of Computational and Systems Biology, The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
| | - Saskia A Hogenhout
- Department of Crop Genetics, The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
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42
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Theißen G, Melzer R, Rümpler F. MADS-domain transcription factors and the floral quartet model of flower development: linking plant development and evolution. Development 2017; 143:3259-71. [PMID: 27624831 DOI: 10.1242/dev.134080] [Citation(s) in RCA: 230] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The floral quartet model of floral organ specification poses that different tetramers of MIKC-type MADS-domain transcription factors control gene expression and hence the identity of floral organs during development. Here, we provide a brief history of the floral quartet model and review several lines of recent evidence that support the model. We also describe how the model has been used in contemporary developmental and evolutionary biology to shed light on enigmatic topics such as the origin of land and flowering plants. Finally, we suggest a novel hypothesis describing how floral quartet-like complexes may interact with chromatin during target gene activation and repression.
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Affiliation(s)
- Günter Theißen
- Department of Genetics, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Rainer Melzer
- School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Florian Rümpler
- Department of Genetics, Friedrich Schiller University Jena, 07743 Jena, Germany
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43
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Ishikawa K, Hashimoto M, Yusa A, Koinuma H, Kitazawa Y, Netsu O, Yamaji Y, Namba S. Dual targeting of a virus movement protein to ER and plasma membrane subdomains is essential for plasmodesmata localization. PLoS Pathog 2017; 13:e1006463. [PMID: 28640879 PMCID: PMC5498070 DOI: 10.1371/journal.ppat.1006463] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 07/05/2017] [Accepted: 06/10/2017] [Indexed: 11/18/2022] Open
Abstract
Plant virus movement proteins (MPs) localize to plasmodesmata (PD) to facilitate virus cell-to-cell movement. Numerous studies have suggested that MPs use a pathway either through the ER or through the plasma membrane (PM). Furthermore, recent studies reported that ER-PM contact sites and PM microdomains, which are subdomains found in the ER and PM, are involved in virus cell-to-cell movement. However, functional relationship of these subdomains in MP traffic to PD has not been described previously. We demonstrate here the intracellular trafficking of fig mosaic virus MP (MPFMV) using live cell imaging, focusing on its ER-directing signal peptide (SPFMV). Transiently expressed MPFMV was distributed predominantly in PD and patchy microdomains of the PM. Investigation of ER translocation efficiency revealed that SPFMV has quite low efficiency compared with SPs of well-characterized plant proteins, calreticulin and CLAVATA3. An MPFMV mutant lacking SPFMV localized exclusively to the PM microdomains, whereas SP chimeras, in which the SP of MPFMV was replaced by an SP of calreticulin or CLAVATA3, localized exclusively to the nodes of the ER, which was labeled with Arabidopsis synaptotagmin 1, a major component of ER-PM contact sites. From these results, we speculated that the low translocation efficiency of SPFMV contributes to the generation of ER-translocated and the microdomain-localized populations, both of which are necessary for PD localization. Consistent with this hypothesis, SP-deficient MPFMV became localized to PD when co-expressed with an SP chimera. Here we propose a new model for the intracellular trafficking of a viral MP. A substantial portion of MPFMV that fails to be translocated is transferred to the microdomains, whereas the remainder of MPFMV that is successfully translocated into the ER subsequently localizes to ER-PM contact sites and plays an important role in the entry of the microdomain-localized MPFMV into PD.
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Affiliation(s)
- Kazuya Ishikawa
- Laboratory of Plant Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Masayoshi Hashimoto
- Laboratory of Plant Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Akira Yusa
- Laboratory of Plant Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Hiroaki Koinuma
- Laboratory of Plant Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Yugo Kitazawa
- Laboratory of Plant Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Osamu Netsu
- Laboratory of Plant Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Yasuyuki Yamaji
- Laboratory of Plant Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Shigetou Namba
- Laboratory of Plant Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, Japan
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Kitazawa Y, Iwabuchi N, Himeno M, Sasano M, Koinuma H, Nijo T, Tomomitsu T, Yoshida T, Okano Y, Yoshikawa N, Maejima K, Oshima K, Namba S. Phytoplasma-conserved phyllogen proteins induce phyllody across the Plantae by degrading floral MADS domain proteins. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:2799-2811. [PMID: 28505304 PMCID: PMC5853863 DOI: 10.1093/jxb/erx158] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 04/13/2017] [Indexed: 05/21/2023]
Abstract
ABCE-class MADS domain transcription factors (MTFs) are key regulators of floral organ development in angiosperms. Aberrant expression of these genes can result in abnormal floral traits such as phyllody. Phyllogen is a virulence factor conserved in phytoplasmas, plant pathogenic bacteria of the class Mollicutes. It triggers phyllody in Arabidopsis thaliana by inducing degradation of A- and E-class MTFs. However, it is still unknown whether phyllogen can induce phyllody in plants other than A. thaliana, although phytoplasma-associated phyllody symptoms are observed in a broad range of angiosperms. In this study, phyllogen was shown to cause phyllody phenotypes in several eudicot species belonging to three different families. Moreover, phyllogen can interact with MTFs of not only angiosperm species including eudicots and monocots but also gymnosperms and a fern, and induce their degradation. These results suggest that phyllogen induces phyllody in angiosperms and inhibits MTF function in diverse plant species.
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Affiliation(s)
- Yugo Kitazawa
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Nozomu Iwabuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Misako Himeno
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Momoka Sasano
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Hiroaki Koinuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Takamichi Nijo
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Tatsuya Tomomitsu
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Tetsuya Yoshida
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Yukari Okano
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Nobuyuki Yoshikawa
- Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka-shi, Iwate, Japan
| | - Kensaku Maejima
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Kenro Oshima
- Faculty of Bioscience, Hosei University, 3-7-2 Kajino-cho, Koganei-shi, Tokyo, Japan
| | - Shigetou Namba
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
- Correspondence:
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Janik K, Mithöfer A, Raffeiner M, Stellmach H, Hause B, Schlink K. An effector of apple proliferation phytoplasma targets TCP transcription factors-a generalized virulence strategy of phytoplasma? MOLECULAR PLANT PATHOLOGY 2017; 18:435-442. [PMID: 27037957 PMCID: PMC6638208 DOI: 10.1111/mpp.12409] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Revised: 03/14/2016] [Accepted: 03/25/2016] [Indexed: 05/04/2023]
Abstract
The plant pathogen Candidatus Phytoplasma mali (P. mali) is the causative agent of apple proliferation, a disease of increasing importance in apple-growing areas within Europe. Despite its economic importance, little is known about the molecular mechanisms of disease manifestation within apple trees. In this study, we identified two TCP (TEOSINTE BRANCHED/CYCLOIDEA/PROLIFERATING CELL FACTOR) transcription factors of Malus x domestica as binding partners of the P. mali SAP11-like effector ATP_00189. Phytohormone analyses revealed an effect of P. mali infection on jasmonates, salicylic acid and abscisic acid levels, showing that P. mali affects phytohormonal levels in apple trees, which is in line with the functions of the effector assumed from its binding to TCP transcription factors. To our knowledge, this is the first characterization of the molecular targets of a P. mali effector and thus provides the basis to better understand symptom development and disease progress during apple proliferation. As SAP11 homologues are found in several Phytoplasma species infecting a broad range of different plants, SAP11-like proteins seem to be key players in phytoplasmal infection.
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Affiliation(s)
- Katrin Janik
- Research Centre for Agriculture and Forestry LaimburgLaimburg 6Auer/OraBZ39040Italy
| | - Axel Mithöfer
- Department of Bioorganic ChemistryMax Planck Institute for Chemical EcologyBeutenberg Campus, Hans‐Knöll‐Str. 8Jena07745Germany
| | - Margot Raffeiner
- Research Centre for Agriculture and Forestry LaimburgLaimburg 6Auer/OraBZ39040Italy
| | - Hagen Stellmach
- Department for Cell and Metabolic BiologyLeibniz Institute of Plant BiochemistryWeinberg 3Halle06120Germany
| | - Bettina Hause
- Department for Cell and Metabolic BiologyLeibniz Institute of Plant BiochemistryWeinberg 3Halle06120Germany
| | - Katja Schlink
- Research Centre for Agriculture and Forestry LaimburgLaimburg 6Auer/OraBZ39040Italy
- Present address:
Present address: Dr. Knoell Consult GmbHMarie‐Curie‐Str. 851377LeverkusenGermany
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46
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Orlovskis Z, Canale MC, Haryono M, Lopes JRS, Kuo CH, Hogenhout SA. A few sequence polymorphisms among isolates of Maize bushy stunt phytoplasma associate with organ proliferation symptoms of infected maize plants. ANNALS OF BOTANY 2017; 119:869-884. [PMID: 28069632 PMCID: PMC5379588 DOI: 10.1093/aob/mcw213] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 08/16/2016] [Indexed: 05/18/2023]
Abstract
Background and Aims Maize bushy stunt phytoplasma (MBSP) is a bacterial pathogen of maize ( Zea mays L.) across Latin America. MBSP belongs to the 16SrI-B sub-group within the genus ' Candidatus Phytoplasma'. MBSP and its insect vector Dalbulus maidis (Hemiptera: Cicadellidae) are restricted to maize; both are thought to have coevolved with maize during its domestication from a teosinte-like ancestor. MBSP-infected maize plants show a diversity of symptoms. and it is likely that MBSP is under strong selection for increased virulence and insect transmission on maize hybrids that are widely grown in Brazil. In this study it was investigated whether the differences in genome sequences of MBSP isolates from two maize-growing regions in South-east Brazil explain variations in symptom severity of the MBSP isolates on various maize genotypes. Methods MBSP isolates were collected from maize production fields in Guaíra and Piracicaba in South-east Brazil for infection assays. One representative isolate was chosen for de novo whole-genome assembly and for the alignment of sequence reads from the genomes of other phytoplasma isolates to detect polymorphisms. Statistical methods were applied to investigate the correlation between variations in disease symptoms of infected maize plants and MBSP sequence polymorphisms. Key Results MBSP isolates contributed consistently to organ proliferation symptoms and maize genotype to leaf necrosis, reddening and yellowing of infected maize plants. The symptom differences are associated with polymorphisms in a phase-variable lipoprotein, which is a candidate effector, and an ATP-dependent lipoprotein ABC export protein, whereas no polymorphisms were observed in other candidate effector genes. Lipoproteins and ABC export proteins activate host defence responses, regulate pathogen attachment to host cells and activate effector secretion systems in other pathogens. Conclusions Polymorphisms in two putative virulence genes among MBSP isolates from maize-growing regions in South-east Brazil are associated with variations in organ proliferation symptoms of MBSP-infected maize plants.
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Affiliation(s)
- Zigmunds Orlovskis
- John Innes Centre, Department of Cell and Developmental Biology, Norwich Research Park, Norwich NR4 7UH, UK
| | - Maria Cristina Canale
- John Innes Centre, Department of Cell and Developmental Biology, Norwich Research Park, Norwich NR4 7UH, UK
- Luiz de Queiroz College of Agriculture, University of São Paulo, Department of Entomology and Acarology, Piracicaba 13·418-900, Brazil
| | - Mindia Haryono
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - João Roberto Spotti Lopes
- Luiz de Queiroz College of Agriculture, University of São Paulo, Department of Entomology and Acarology, Piracicaba 13·418-900, Brazil
| | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Saskia A. Hogenhout
- John Innes Centre, Department of Cell and Developmental Biology, Norwich Research Park, Norwich NR4 7UH, UK
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Perilla-Henao LM, Casteel CL. Vector-Borne Bacterial Plant Pathogens: Interactions with Hemipteran Insects and Plants. FRONTIERS IN PLANT SCIENCE 2016; 7:1163. [PMID: 27555855 PMCID: PMC4977473 DOI: 10.3389/fpls.2016.01163] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 07/20/2016] [Indexed: 05/22/2023]
Abstract
Hemipteran insects are devastating pests of crops due to their wide host range, rapid reproduction, and ability to transmit numerous plant-infecting pathogens as vectors. While the field of plant-virus-vector interactions has flourished in recent years, plant-bacteria-vector interactions remain poorly understood. Leafhoppers and psyllids are by far the most important vectors of bacterial pathogens, yet there are still significant gaps in our understanding of their feeding behavior, salivary secretions, and plant responses as compared to important viral vectors, such as whiteflies and aphids. Even with an incomplete understanding of plant-bacteria-vector interactions, some common themes have emerged: (1) all known vector-borne bacteria share the ability to propagate in the plant and insect host; (2) particular hemipteran families appear to be incapable of transmitting vector-borne bacteria; (3) all known vector-borne bacteria have highly reduced genomes and coding capacity, resulting in host-dependence; and (4) vector-borne bacteria encode proteins that are essential for colonization of specific hosts, though only a few types of proteins have been investigated. Here, we review the current knowledge on important vector-borne bacterial pathogens, including Xylella fastidiosa, Spiroplasma spp., Liberibacter spp., and 'Candidatus Phytoplasma spp.'. We then highlight recent approaches used in the study of vector-borne bacteria. Finally, we discuss the application of this knowledge for control and future directions that will need to be addressed in the field of vector-plant-bacteria interactions.
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Affiliation(s)
| | - Clare L. Casteel
- Department of Plant Pathology, University of California at Davis, Davis, CAUSA
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48
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Yan H, Zhang H, Wang Q, Jian H, Qiu X, Baudino S, Just J, Raymond O, Gu L, Wang J, Bendahmane M, Tang K. The Rosa chinensis cv. Viridiflora Phyllody Phenotype Is Associated with Misexpression of Flower Organ Identity Genes. FRONTIERS IN PLANT SCIENCE 2016; 7:996. [PMID: 27462328 PMCID: PMC4941542 DOI: 10.3389/fpls.2016.00996] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 06/24/2016] [Indexed: 05/21/2023]
Abstract
Phyllody is a flower abnormality in which leaf-like structures replace flower organs in all whorls. Here, we investigated the origin and the molecular mechanism of phyllody phenotype in Rosa chinensis cv. Viridiflora, an ancient naturally occurring Chinese mutant cultivar. Reciprocal grafting experiments and microscopy analyses, demonstrated that the phyllody phenotype in Viridiflora is not associated with phytoplasmas infection. Transcriptome comparisons by the mean of RNA-Seq identified 672 up-regulated and 666 down-regulated genes in Viridiflora compared to its closely related genotype R. chinensis cv. Old Blush. A fraction of these genes are putative homologs of genes known to be involved in flower initiation and development. We show that in flower whorl 2 of Viridiflora, a down-regulation of the floral organ identity genes RcPISTILLATA (RcPI), RcAPETALA3 (RcAP3) and RcSEPALLATA3 (RcSEP3), together with an up-regulation of the putative homolog of the gene SUPPRESSOR of OVEREXPRESSION of CONSTANS1 (RcSOC1) are likely at the origin of the loss of petal identity and leaf-like structures formation. In whorl 3 of Viridiflora, ectopic expression of RcAPETALA2 (RcAP2) along with the down regulation of RcPI, RcAP3, and RcSEP3 is associated with loss of stamens identity and leaf-like structures formation. In whorl 4, the ectopic expression of RcAP2 associated with a down-regulation of RcSEP3 and of the C-class gene RcAGAMOUS correlate with loss of pistil identity. The latter also suggested the antagonist effect between the A and C class genes in the rose. Together, these data suggest that modified expression of the ABCE flower organ identity genes is associated with the phyllody phenotype in the rose Viridiflora and that these genes are important for normal flower organs development.
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Affiliation(s)
- Huijun Yan
- Flower Research Institute of Yunnan Academy of Agricultural SciencesKunming, China
| | - Hao Zhang
- Flower Research Institute of Yunnan Academy of Agricultural SciencesKunming, China
| | - Qigang Wang
- Flower Research Institute of Yunnan Academy of Agricultural SciencesKunming, China
| | - Hongying Jian
- Flower Research Institute of Yunnan Academy of Agricultural SciencesKunming, China
| | - Xianqin Qiu
- Flower Research Institute of Yunnan Academy of Agricultural SciencesKunming, China
| | - Sylvie Baudino
- Université de Lyon, UJM-Saint-Etienne, CNRS, BVpam FRE 3727Saint-Etienne, France
| | - Jeremy Just
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRALyon, France
| | - Olivier Raymond
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRALyon, France
| | - Lianfeng Gu
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Jihua Wang
- Flower Research Institute of Yunnan Academy of Agricultural SciencesKunming, China
| | - Mohammed Bendahmane
- Laboratoire de Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRALyon, France
| | - Kaixue Tang
- Flower Research Institute of Yunnan Academy of Agricultural SciencesKunming, China
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Tan CM, Li CH, Tsao NW, Su LW, Lu YT, Chang SH, Lin YY, Liou JC, Hsieh LC, Yu JZ, Sheue CR, Wang SY, Lee CF, Yang JY. Phytoplasma SAP11 alters 3-isobutyl-2-methoxypyrazine biosynthesis in Nicotiana benthamiana by suppressing NbOMT1. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:4415-25. [PMID: 27279277 PMCID: PMC5301940 DOI: 10.1093/jxb/erw225] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Phytoplasmas are bacterial phytopathogens that release virulence effectors into sieve cells and act systemically to affect the physiological and morphological state of host plants to promote successful pathogenesis. We show here that transgenic Nicotiana benthamiana lines expressing the secreted effector SAP11 from Candidatus Phytoplasma mali exhibit an altered aroma phenotype. This phenomenon is correlated with defects in the development of glandular trichomes and the biosynthesis of 3-isobutyl-2-methoxypyrazine (IBMP). IBMP is a volatile organic compound (VOC) synthesized by an O-methyltransferase, via a methylation step, from a non-volatile precursor, 3-isobutyl-2-hydroxypyrazine (IBHP). Based on comparative and functional genomics analyses, NbOMT1, which encodes an O-methyltransferase, was found to be highly suppressed in SAP11-transgenic plants. We further silenced NbOMT1 through virus-induced gene silencing and demonstrated that this enzyme influenced the accumulation of IBMP in N. benthamiana In vitro biochemical analyses also showed that NbOMT1 can catalyse IBHP O-methylation in the presence of S-adenosyl-L-methionine. Our study suggests that the phytoplasma effector SAP11 has the ability to modulate host VOC emissions. In addition, we also demonstrated that SAP11 destabilized TCP transcription factors and suppressed jasmonic acid responses in N. benthamiana These findings provide valuable insights into understanding how phytoplasma effectors influence plant volatiles.
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Affiliation(s)
- Choon Meng Tan
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taiwan
| | - Chia-Hua Li
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Nai-Wen Tsao
- Department of Forestry, National Chung Hsing University, Taichung 402, Taiwan
| | - Li-Wen Su
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Yen-Ting Lu
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taiwan
| | - Shu Heng Chang
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Yi Yu Lin
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Jyun-Cyuan Liou
- Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Li-Ching Hsieh
- Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung 402, Taiwan
| | - Jih-Zu Yu
- Department of Applied Zoology, Agricultural Research Institute, Taichung 413, Taiwan
| | - Chiou-Rong Sheue
- Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan
| | - Sheng-Yang Wang
- Department of Forestry, National Chung Hsing University, Taichung 402, Taiwan
| | - Chin-Fa Lee
- Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Jun-Yi Yang
- Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taiwan Institute of Biotechnology, National Chung Hsing University, Taichung 402, Taiwan NCHU-UCD Plant and Food Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
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50
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Thiriet-Rupert S, Carrier G, Chénais B, Trottier C, Bougaran G, Cadoret JP, Schoefs B, Saint-Jean B. Transcription factors in microalgae: genome-wide prediction and comparative analysis. BMC Genomics 2016; 17:282. [PMID: 27067009 PMCID: PMC4827209 DOI: 10.1186/s12864-016-2610-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 04/05/2016] [Indexed: 11/28/2022] Open
Abstract
Background Studying transcription factors, which are some of the key players in gene expression, is of outstanding interest for the investigation of the evolutionary history of organisms through lineage-specific features. In this study we performed the first genome-wide TF identification and comparison between haptophytes and other algal lineages. Results For TF identification and classification, we created a comprehensive pipeline using a combination of BLAST, HMMER and InterProScan software. The accuracy evaluation of the pipeline shows its applicability for every alga, plant and cyanobacterium, with very good PPV and sensitivity. This pipeline allowed us to identify and classified the transcription factor complement of the three haptophytes Tisochrysis lutea, Emiliania huxleyi and Pavlova sp.; the two stramenopiles Phaeodactylum tricornutum and Nannochloropsis gaditana; the chlorophyte Chlamydomonas reinhardtii and the rhodophyte Porphyridium purpureum. By using T. lutea and Porphyridium purpureum, this work extends the variety of species included in such comparative studies, allowing the detection and detailed study of lineage-specific features, such as the presence of TF families specific to the green lineage in Porphyridium purpureum, haptophytes and stramenopiles. Our comprehensive pipeline also allowed us to identify fungal and cyanobacterial TF families in the algal nuclear genomes. Conclusions This study provides examples illustrating the complex evolutionary history of algae, some of which support the involvement of a green alga in haptophyte and stramenopile evolution. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2610-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stanislas Thiriet-Rupert
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France.
| | - Grégory Carrier
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
| | - Benoît Chénais
- MicroMar, Mer Molécules Santé, IUML - FR 3473 CNRS, University of Le Mans, Le Mans, France
| | - Camille Trottier
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
| | - Gaël Bougaran
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
| | - Jean-Paul Cadoret
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
| | - Benoît Schoefs
- MicroMar, Mer Molécules Santé, IUML - FR 3473 CNRS, University of Le Mans, Le Mans, France
| | - Bruno Saint-Jean
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
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