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Jiang Z, Wang N, Chen J, Xu H, Zhu W, Shi D, Qian C, Shi J, Hu X, Xu Z, Wang D, Yang X, Liu J, Duan H. Structural optimization and discovery of high effective isopropanolamine-based TPS1 inhibitors as promising broad-spectrum fungicide candidates. Eur J Med Chem 2025; 290:117553. [PMID: 40153931 DOI: 10.1016/j.ejmech.2025.117553] [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: 02/26/2025] [Revised: 03/18/2025] [Accepted: 03/21/2025] [Indexed: 04/01/2025]
Abstract
To address the growing resistance and environmental issues of existing fungicides, the development of novel broad-spectrum fungicides based on new targets, such as TPS1, has been prioritized. However, related research remains limited. In this study, we optimized our previously reported isopropanolamine-based MoTPS1 inhibitor, j11, by replacing its groups on both sides of its isopropanolamine linker with sulfonamide and 1,2,4-triazole fragments through a fragment replacement combining rational design approach. This approach led to the identification of novel isopropanolamine compounds, including g12, g18, o1, and o3, exhibiting significantly improved TPS1 inhibition compared to j11, with IC50 values against MoTPS1 and BcTPS1 of 8.38-14.73 and 38.70-59.99 μM, respectively. The interaction mechanism research confirmed that hydrogen bonds and salt bridges between the novel isopropanolamine compounds and the Glu396 residue in MoTPS1 were crucial during their interaction. Plant leaf and fruit inoculation experiment revealed that these novel isopropanolamine compounds exhibiting substantial inhibition against MoTPS1 and BcTPS1 significantly suppressed the infection of Magnaporthe oryzae and Botrytis cinerea. Preliminary fungicidal mechanism studies indicated that these novel isopropanolamine compounds disrupted various fungal physiological processes including sporulation, conidia germination, appressorium formation, and turgor pressure accumulation within appressorium, while also causing conidia deformation. The hyphal growth inhibition assay against various plant pathogenic fungi suggested that the novel isopropanolamine compounds such as o1 and o3 held the potential as broad-spectrum fungicide candidates with EC50 values of 2.80-17.55 μg/mL. The toxicological assessment suggested that compounds o1 and o3 had no potential toxicity towards diverse non-target organisms. This study provided a valuable insight for optimizing and developing high effective TPS1 inhibitors to be applied in the control of plant diseases.
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Affiliation(s)
- Zhiyang Jiang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Na Wang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Jinxiu Chen
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Huan Xu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Wenya Zhu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Dongmei Shi
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Chen Qian
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Jie Shi
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Xinyue Hu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Zhijian Xu
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Dongli Wang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Xinling Yang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Junfeng Liu
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China.
| | - Hongxia Duan
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China.
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Xiao Q, Zhang L, Xu X, Dai R, Tan Y, Li X, Jin D, Fan Y. Nitrogen-Metabolism Inhibitor NmrA Regulates Conidial Production, Melanin Synthesis, and Virulence in Phytopathogenic Fungus Verticillium dahliae. PHYTOPATHOLOGY 2025; 115:281-289. [PMID: 39688539 DOI: 10.1094/phyto-07-24-0226-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: 12/18/2024]
Abstract
NmrA homologs have been reported as conserved regulators of nitrogen metabolite repression in various fungi. Here, we identified an NmrA homolog in Verticillium dahliae and reported its functions in nitrogen utilization, growth and development, and pathogenesis. VdNmrA interacts with the V. dahliae AreA protein and regulates the expression of a typical NMR target, the formamidase gene. VdNmrA deletion mutants exhibited significantly slower colony growth on media with Gln or Arg. Furthermore, VdNmrA deletion impaired hyphal growth, spore production, hyperosmotic stress tolerance, and melanin biosynthesis. Fewer reactive oxygen species were produced in VdNmrA mutants, and the NADPH oxidase genes noxA and noxB showed lowered expression levels compared with the wild type. VdNmrA mutants exhibited reduced virulence on cotton and Arabidopsis compared with wild-type strains. Our results indicated that VdNmrA functioned as a nitrogen metabolite repression repressor and played important roles in nutrient utilization, fungal development, stress tolerance, and pathogenicity in V. dahliae.
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Affiliation(s)
- Qi Xiao
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Leyuan Zhang
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Xueping Xu
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Renyu Dai
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Yingqing Tan
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Xianbi Li
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Dan Jin
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Yanhua Fan
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
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Wang J, Zou Y, Xia Y, Jin K. MaNrtB, a Putative Nitrate Transporter, Contributes to Stress Tolerance and Virulence in the Entomopathogenic Fungus Metarhizium acridum. J Fungi (Basel) 2025; 11:111. [PMID: 39997405 PMCID: PMC11855974 DOI: 10.3390/jof11020111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2024] [Revised: 01/28/2025] [Accepted: 01/30/2025] [Indexed: 02/26/2025] Open
Abstract
Nitrogen is an essential nutrient that frequently determines the growth rate of fungi. Nitrate transporter proteins (Nrts) play a crucial role in the cellular absorption of nitrate from the environment. Entomopathogenic fungi (EPF) have shown their potential in the biological control of pests. Thus, comprehending the mechanisms that govern the pathogenicity and stress tolerance of EPF is helpful in improving the effectiveness and practical application of these fungal biocontrol agents. In this study, we utilized homologous recombination to create MaNrtB deletion mutants and complementation strains. We systematically investigated the biological functions of the nitrate transporter protein gene MaNrtB in M. acridum. Our findings revealed that the disruption of MaNrtB resulted in delayed conidial germination without affecting conidial production. Stress tolerance assays demonstrated that the MaNrtB disruption strain was more vulnerable to UV-B irradiation, hyperosmotic stress, and cell wall disturbing agents, yet it exhibited increased heat resistance compared to the wild-type strain. Bioassays on the locust Locusta migratoria manilensis showed that the disruption of MaNrtB impaired the fungal virulence owing to the reduced appressorium formation on the insect cuticle and the attenuated growth in the locust hemolymph. These findings provide new perspectives for understanding the pathogenesis of EPF.
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Affiliation(s)
- Jia Wang
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China; (J.W.)
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing 401331, China
- National Engineering Research Center of Microbial Pesticides, Chongqing 401331, China
| | - Yuneng Zou
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China; (J.W.)
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing 401331, China
- National Engineering Research Center of Microbial Pesticides, Chongqing 401331, China
| | - Yuxian Xia
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China; (J.W.)
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing 401331, China
- National Engineering Research Center of Microbial Pesticides, Chongqing 401331, China
| | - Kai Jin
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China; (J.W.)
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing 401331, China
- National Engineering Research Center of Microbial Pesticides, Chongqing 401331, China
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Richter M, Segal LM, Rocha RO, Rokaya N, de Queiroz AR, Riekhof WR, Roston RL, Wilson RA. Membrane fluidity control by the Magnaporthe oryzae acyl-CoA binding protein sets the thermal range for host rice cell colonization. PLoS Pathog 2024; 20:e1012738. [PMID: 39585916 PMCID: PMC11627410 DOI: 10.1371/journal.ppat.1012738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 12/09/2024] [Accepted: 11/10/2024] [Indexed: 11/27/2024] Open
Abstract
Following leaf cuticle penetration by specialized appressorial cells, the devastating blast fungus Magnaporthe oryzae grows as invasive hyphae (IH) in living rice cells. IH are separated from host cytoplasm by plant-derived membranes forming an apoplastic compartment and a punctate biotrophic interfacial complex (BIC) that mediate the molecular host-pathogen interaction. What molecular and cellular processes determine the temperature range for this biotrophic growth stage is an unanswered question pertinent to a broader understanding of how phytopathogens may cope with environmental stresses arising under climate change. Here, we shed light on thermal adaptation in M. oryzae by disrupting the ACB1 gene encoding the single acyl-CoA-binding protein, an intracellular transporter of long-chain acyl-CoA esters. Loss of ACB1 affected fatty acid desaturation levels and abolished pathogenicity at optimal (26°C) and low (22°C) but not elevated (29°C) infection temperatures (the latter following post-penetration shifts from 26°C). Relative to wild type, the Δacb1 mutant strain exhibited poor vegetative growth and impaired membrane trafficking at 22°C and 26°C, but not at 29°C. In planta, Δacb1 biotrophic growth was inhibited at 26°C-which was accompanied by a multi-BIC phenotype-but not at 29°C, where BIC formation was normal. Underpinning the Δacb1 phenotype was impaired membrane fluidity at 22°C and 26°C but not at elevated temperatures, indicating Acb1 suppresses membrane rigidity at optimal- and suboptimal- but not supraoptimal temperatures. Deducing a temperature-dependent role for Acb1 in maintaining membrane fluidity homeostasis reveals how the thermal range for rice blast disease is both mechanistically determined and wider than hitherto appreciated.
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Affiliation(s)
- Michael Richter
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Lauren M. Segal
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Raquel O. Rocha
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Nisha Rokaya
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Aline R. de Queiroz
- Center for Plant Science Innovation, Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Wayne R. Riekhof
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Rebecca L. Roston
- Center for Plant Science Innovation, Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Richard A. Wilson
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
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Li F, Lu D, Meng F, Tian C. Transcription Factor CgSte12 Regulates Pathogenicity by Affecting Appressorium Structural Development in the Anthracnose-Causing Fungus Colletotrichum gloeosporioides. PHYTOPATHOLOGY 2024; 114:1832-1842. [PMID: 38748933 DOI: 10.1094/phyto-12-23-0484-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2024]
Abstract
Colletotrichum gloeosporioides is the causal agent of poplar anthracnose, which induces major economic losses and adversely affects the ecosystem services of poplar forests. The appressorium serves as a penetration structure for many pathogenic fungi, including C. gloeosporioides. The production of mucilage and the formation of penetration pegs are critically important for the appressorium-mediated penetration of host tissues. We previously found that CgPmk1 is a key protein involved in appressorium formation, penetration, and pathogenicity. Although CgSte12, which is a transcription factor that functions downstream of CgPmk1, regulates the formation of penetration pegs, its role in C. gloeosporioides appressorium development and pathogenicity has not been elucidated. Here, we developed C. gloeosporioides CgSTE12 mutants and characterized the molecular and cellular functions of CgSTE12. The results showed that mycelial growth and morphology were not affected in the CgSTE12 knockout mutants, which produced normal melanized appressoria. However, these mutants had less mucilage secreted around the appressoria, impaired appressorial cone formation, and the inability to form penetration pores and pegs, which ultimately led to a significant loss of pathogenicity. Our comparative transcriptome analysis revealed that CgSte12 controls the expression of genes involved in appressorium development and function, including genes encoding cutinases, NADPH oxidase, spermine biosynthesis-related proteins, ceramide biosynthesis-related proteins, fatty acid metabolism-related proteins, and glycerophospholipid metabolism-related proteins. Overall, our findings indicate that CgSte12 is a critical regulator of appressorium development and affects C. gloeosporioides pathogenicity by modulating the structural integrity of appressoria.
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Affiliation(s)
- Fuhan Li
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Dongxiao Lu
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Fanli Meng
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
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Huang Q, Li F, Meng F. Functional Characterization of the Transcription Factor Gene CgHox7 in Colletotrichum gloeosporioides, Which Is Responsible for Poplar Anthracnose. J Fungi (Basel) 2024; 10:505. [PMID: 39057390 PMCID: PMC11278219 DOI: 10.3390/jof10070505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 07/16/2024] [Accepted: 07/18/2024] [Indexed: 07/28/2024] Open
Abstract
Colletotrichum gloeosporioides is the main pathogen that causes poplar anthracnose. This hemibiotrophic fungus, which can severely decrease the economic benefits and ecological functions of poplar trees, infects the host by forming an appressorium. Hox7 is an important regulatory factor that functions downstream of the Pmk1 MAPK signaling pathway. In this study, we investigated the effect of deleting CgHox7 on C. gloeosporioides. The conidia of the ΔCgHox7 deletion mutant germinated on a GelBond membrane to form non-melanized hyphal structures, but were unable to form appressoria. The deletion of CgHox7 weakened the ability of hyphae to penetrate a cellophane membrane and resulted in decreased virulence on poplar leaves. Furthermore, deleting CgHox7 affected the oxidative stress response. In the initial stage of appressorium formation, the accumulation of reactive oxygen species differed between the ΔCgHox7 deletion mutant and the wild-type control. Moreover, CgHox7 expression was necessary for maintaining cell wall integrity. Considered together, these results indicate that CgHox7 is a transcription factor with crucial regulatory effects on appressorium formation and the pathogenicity of C. gloeosporioides.
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Affiliation(s)
- Qiuyi Huang
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing 100083, China; (Q.H.); (F.L.)
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Fuhan Li
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing 100083, China; (Q.H.); (F.L.)
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Fanli Meng
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing 100083, China; (Q.H.); (F.L.)
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
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Ren Z, Dong X, Guan L, Yang L, Liu C, Cai X, Hu H, Lv Z, Liu H, Zheng L, Huang J, Wilson RA, Chen XL. Sirt5-mediated lysine desuccinylation regulates oxidative stress adaptation in Magnaporthe oryzae during host intracellular infection. THE NEW PHYTOLOGIST 2024; 242:1257-1274. [PMID: 38481385 DOI: 10.1111/nph.19683] [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: 01/14/2024] [Accepted: 02/07/2024] [Indexed: 04/12/2024]
Abstract
Plant pathogenic fungi elaborate numerous detoxification strategies to suppress host reactive oxygen species (ROS), but their coordination is not well-understood. Here, we show that Sirt5-mediated protein desuccinylation in Magnaporthe oryzae is central to host ROS detoxification. SIRT5 encodes a desuccinylase important for virulence via adaptation to host oxidative stress. Quantitative proteomics analysis identified a large number of succinylated proteins targeted by Sirt5, most of which were mitochondrial proteins involved in oxidative phosphorylation, TCA cycle, and fatty acid oxidation. Deletion of SIRT5 resulted in hypersuccinylation of detoxification-related enzymes, and significant reduction in NADPH : NADP+ and GSH : GSSG ratios, disrupting redox balance and impeding invasive growth. Sirt5 desuccinylated thioredoxin Trx2 and glutathione peroxidase Hyr1 to activate their enzyme activity, likely by affecting proper folding. Altogether, this work demonstrates the importance of Sirt5-mediated desuccinylation in controlling fungal process required for detoxifying host ROS during M. oryzae infection.
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Affiliation(s)
- Zhiyong Ren
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiang Dong
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lun Guan
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lei Yang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Caiyun Liu
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xuan Cai
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hong Hu
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ziwei Lv
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hao Liu
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lu Zheng
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Junbin Huang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Richard A Wilson
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Xiao-Lin Chen
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
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de Oliveira TC, Freyria NJ, Sarmiento-Villamil JL, Porth I, Tanguay P, Bernier L. Unraveling the transcriptional features and gene expression networks of pathogenic and saprotrophic Ophiostoma species during the infection of Ulmus americana. Microbiol Spectr 2024; 12:e0369423. [PMID: 38230934 PMCID: PMC10845970 DOI: 10.1128/spectrum.03694-23] [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: 10/17/2023] [Accepted: 12/08/2023] [Indexed: 01/18/2024] Open
Abstract
American elm (Ulmus americana), highly prized for its ornamental value, has suffered two successive outbreaks of Dutch elm disease (DED) caused by ascomycete fungi belonging to the genus Ophiostoma. To identify the genes linked to the pathogenicity of different species and lineages of Ophiostoma, we inoculated 2-year-old U. americana saplings with six strains representing three species of DED fungi, and one strain of the saprotroph Ophiostoma quercus. Differential expression analyses were performed following RNA sequencing of fungal transcripts recovered at 3- and 10-days post-infection. Based on a total of 8,640 Ophiostoma genes, we observed a difference in fungal gene expression depending on the strain inoculated and the time of incubation in host tissue. Some genes overexpressed in the more virulent strains of Ophiostoma encode hydrolases that possibly act synergistically. A mutant of Ophiostoma novo-ulmi in which the gene encoding the ogf1 transcription factor had been deleted did not produce transcripts for the gene encoding the hydrophobin cerato-ulmin and was less virulent. Weighted gene correlation network analyses identified several candidate pathogenicity genes distributed among 13 modules of interconnected genes.IMPORTANCEOphiostoma is a genus of cosmopolitan fungi that belongs to the family Ophiostomataceae and includes the pathogens responsible for two devastating pandemics of Dutch elm disease (DED). As the mechanisms of action of DED agents remain unclear, we carried out the first comparative transcriptomic study including representative strains of the three Ophiostoma species causing DED, along with the phylogenetically close saprotrophic species Ophiostoma quercus. Statistical analyses of the fungal transcriptomes recovered at 3 and 10 days following infection of Ulmus americana saplings highlighted several candidate genes associated with virulence and host-pathogen interactions wherein each strain showed a distinct transcriptome. The results of this research underscore the importance of investigating the transcriptional behavior of different fungal taxa to understand their pathogenicity and virulence in relation to the timeline of infection.
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Affiliation(s)
- Thais C. de Oliveira
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, Quebec, Canada
- Centre d’étude de la Forêt, Faculté de foresterie, de géographie et de géomatique, Université Laval, Québec, Quebec, Canada
| | - Nastasia J. Freyria
- Department of Natural Resource Sciences, McGill University, St. Anne-de-Bellevue, Quebec, Quebec, Canada
| | - Jorge Luis Sarmiento-Villamil
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, Quebec, Canada
- Centre d’étude de la Forêt, Faculté de foresterie, de géographie et de géomatique, Université Laval, Québec, Quebec, Canada
- Instituto de Hortofruticultura Subtropical y Mediterránea, Consejo Superior de Investigaciones Científicas-Universidad de Málaga (IHSM-CSIC-UMA), Estación Experimental “La Mayora”, Málaga, Spain
| | - Ilga Porth
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, Quebec, Canada
- Centre d’étude de la Forêt, Faculté de foresterie, de géographie et de géomatique, Université Laval, Québec, Quebec, Canada
| | - Philippe Tanguay
- Canadian Forest Service, Natural Resources Canada, Laurentian Forestry Centre, Québec, Quebec, Canada
| | - Louis Bernier
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, Quebec, Canada
- Centre d’étude de la Forêt, Faculté de foresterie, de géographie et de géomatique, Université Laval, Québec, Quebec, Canada
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9
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Qiu P, Li J, Zhang L, Chen K, Shao J, Zheng B, Yuan H, Qi J, Yue L, Hu Q, Ming Y, Liu S, Long L, Gu J, Zhang X, Lindsey K, Gao W, Wu H, Zhu L. Polyethyleneimine-coated MXene quantum dots improve cotton tolerance to Verticillium dahliae by maintaining ROS homeostasis. Nat Commun 2023; 14:7392. [PMID: 37968319 PMCID: PMC10651998 DOI: 10.1038/s41467-023-43192-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 11/02/2023] [Indexed: 11/17/2023] Open
Abstract
Verticillium dahliae is a soil-borne hemibiotrophic fungal pathogen that threatens cotton production worldwide. In this study, we assemble the genomes of two V. dahliae isolates: the more virulence and defoliating isolate V991 and nondefoliating isolate 1cd3-2. Transcriptome and comparative genomics analyses show that genes associated with pathogen virulence are mostly induced at the late stage of infection (Stage II), accompanied by a burst of reactive oxygen species (ROS), with upregulation of more genes involved in defense response in cotton. We identify the V991-specific virulence gene SP3 that is highly expressed during the infection Stage II. V. dahliae SP3 knock-out strain shows attenuated virulence and triggers less ROS production in cotton plants. To control the disease, we employ polyethyleneimine-coated MXene quantum dots (PEI-MQDs) that possess the ability to remove ROS. Cotton seedlings treated with PEI-MQDs are capable of maintaining ROS homeostasis with enhanced peroxidase, catalase, and glutathione peroxidase activities and exhibit improved tolerance to V. dahliae. These results suggest that V. dahliae trigger ROS production to promote infection and scavenging ROS is an effective way to manage this disease. This study reveals a virulence mechanism of V. dahliae and provides a means for V. dahliae resistance that benefits cotton production.
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Affiliation(s)
- Ping Qiu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Jiayue Li
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Lin Zhang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Kun Chen
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Jianmin Shao
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Baoxin Zheng
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Hang Yuan
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Jie Qi
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Lin Yue
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Qin Hu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Yuqing Ming
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Shiming Liu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Lu Long
- State Key Laboratory of Cotton Biology, Henan Key Laboratory of Plant Stress Biology, Henan University, Kaifeng, 475004, People's Republic of China
| | - Jiangjiang Gu
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- School of Science, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Xianlong Zhang
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Keith Lindsey
- Department of Biosciences, Durham University, Durham, DH1 3LE, UK
| | - Wei Gao
- State Key Laboratory of Cotton Biology, Henan Key Laboratory of Plant Stress Biology, Henan University, Kaifeng, 475004, People's Republic of China.
| | - Honghong Wu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, The Center of Crop Nanobiotechnology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
- Shenzhen Institute of Nutrition and Health, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, People's Republic of China.
| | - Longfu Zhu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
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10
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Jiang Z, Shi D, Chen Y, Li H, Wang J, Lv X, Zi Y, Wang D, Xu Z, Huang J, Liu J, Duan H. Discovery of novel isopropanolamine inhibitors against MoTPS1 as potential fungicides with unique mechanisms. Eur J Med Chem 2023; 260:115755. [PMID: 37672934 DOI: 10.1016/j.ejmech.2023.115755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 08/13/2023] [Accepted: 08/22/2023] [Indexed: 09/08/2023]
Abstract
The resistance and ecotoxicity of fungicides seriously restrict our ability to effectively control Magnaporthe oryzae. Discovering fungicidal agents based on novel targets, including MoTPS1, could efficiently address this situation. Here, we identified a hit VS-10 containing an isopropanolamine fragment as a novel MoTPS1 inhibitor through virtual screening, and forty-four analogs were synthesized by optimizing the structure of VS-10. Utilizing our newly established ion-pair chromatography (IPC) and leaf inoculation methods, we found that compared to VS-10, its analog j11 exhibited substantially greater inhibitory activity against both MoTPS1 and the pathogenicity of M. oryzae. Molecular simulations clarified that the electrostatic interactions between the bridging moiety of isopropanolamine and residue Glu396 of contributed significantly to the binding of j11 and MoTPS1. We preliminarily revealed the unique fungicidal mechanism of j11, which mainly impeded the infection of M. oryzae by decreasing sporulation, killing a small portion of conidia and interfering with the accumulation of turgor pressure in appressoria. Thus, in this study, a novel fungicide candidate with a unique mechanism targeting MoTPS1 was screened and discovered.
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Affiliation(s)
- Zhiyang Jiang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Dongmei Shi
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Yitong Chen
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Huilin Li
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Jin'e Wang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Xinrui Lv
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Yunjiang Zi
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Dongli Wang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Zhijian Xu
- CAS Key Laboratory of Receptor Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Jiaxing Huang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China
| | - Junfeng Liu
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China.
| | - Hongxia Duan
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, 100193, China; Key Laboratory of National Forestry and Grassland Administration on Pest Chemical Control, China Agricultural University, Beijing, 100193, China.
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11
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Kerkaert JD, Huberman LB. Regulation of nutrient utilization in filamentous fungi. Appl Microbiol Biotechnol 2023; 107:5873-5898. [PMID: 37540250 PMCID: PMC10983054 DOI: 10.1007/s00253-023-12680-4] [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: 04/19/2023] [Revised: 06/29/2023] [Accepted: 07/04/2023] [Indexed: 08/05/2023]
Abstract
Organisms must accurately sense and respond to nutrients to survive. In filamentous fungi, accurate nutrient sensing is important in the establishment of fungal colonies and in continued, rapid growth for the exploitation of environmental resources. To ensure efficient nutrient utilization, fungi have evolved a combination of activating and repressing genetic networks to tightly regulate metabolic pathways and distinguish between preferred nutrients, which require minimal energy and resources to utilize, and nonpreferred nutrients, which have more energy-intensive catabolic requirements. Genes necessary for the utilization of nonpreferred carbon sources are activated by transcription factors that respond to the presence of the specific nutrient and repressed by transcription factors that respond to the presence of preferred carbohydrates. Utilization of nonpreferred nitrogen sources generally requires two transcription factors. Pathway-specific transcription factors respond to the presence of a specific nonpreferred nitrogen source, while another transcription factor activates genes in the absence of preferred nitrogen sources. In this review, we discuss the roles of transcription factors and upstream regulatory genes that respond to preferred and nonpreferred carbon and nitrogen sources and their roles in regulating carbon and nitrogen catabolism. KEY POINTS: • Interplay of activating and repressing transcriptional networks regulates catabolism. • Nutrient-specific activating transcriptional pathways provide metabolic specificity. • Repressing regulatory systems differentiate nutrients in mixed nutrient environments.
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Affiliation(s)
- Joshua D Kerkaert
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | - Lori B Huberman
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA.
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12
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Li G, Dulal N, Gong Z, Wilson RA. Unconventional secretion of Magnaporthe oryzae effectors in rice cells is regulated by tRNA modification and codon usage control. Nat Microbiol 2023; 8:1706-1716. [PMID: 37563288 DOI: 10.1038/s41564-023-01443-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/04/2023] [Indexed: 08/12/2023]
Abstract
Microbial pathogens deploy effector proteins to manipulate host cell innate immunity, often using poorly understood unconventional secretion routes. Transfer RNA (tRNA) anticodon modifications are universal, but few biological functions are known. Here, in the rice blast fungus Magnaporthe oryzae, we show how unconventional effector secretion depends on tRNA modification and codon usage. We characterized the M. oryzae Uba4-Urm1 sulfur relay system mediating tRNA anticodon wobble uridine 2-thiolation (s2U34), a conserved modification required for efficient decoding of AA-ending cognate codons. Loss of s2U34 abolished the translation of AA-ending codon-rich messenger RNAs encoding unconventionally secreted cytoplasmic effectors, but mRNAs encoding endoplasmic reticulum-Golgi-secreted apoplastic effectors were unaffected. Increasing near-cognate tRNA acceptance, or synonymous AA- to AG-ending codon changes in PWL2, remediated cytoplasmic effector production in Δuba4. In UBA4+, expressing recoded PWL2 caused Pwl2 super-secretion that destabilized the host-fungus interface. Thus, U34 thiolation and codon usage tune pathogen unconventional effector secretion in host rice cells.
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Affiliation(s)
- Gang Li
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Nawaraj Dulal
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Ziwen Gong
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Richard A Wilson
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA.
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13
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Li G, Gong Z, Dulal N, Marroquin-Guzman M, Rocha RO, Richter M, Wilson RA. A protein kinase coordinates cycles of autophagy and glutaminolysis in invasive hyphae of the fungus Magnaporthe oryzae within rice cells. Nat Commun 2023; 14:4146. [PMID: 37438395 DOI: 10.1038/s41467-023-39880-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 06/27/2023] [Indexed: 07/14/2023] Open
Abstract
The blast fungus Magnaporthe oryzae produces invasive hyphae in living rice cells during early infection, separated from the host cytoplasm by plant-derived interfacial membranes. However, the mechanisms underpinning this intracellular biotrophic growth phase are poorly understood. Here, we show that the M. oryzae serine/threonine protein kinase Rim15 promotes biotrophic growth by coordinating cycles of autophagy and glutaminolysis in invasive hyphae. Alongside inducing autophagy, Rim15 phosphorylates NAD-dependent glutamate dehydrogenase, resulting in increased levels of α-ketoglutarate that reactivate target-of-rapamycin (TOR) kinase signaling, which inhibits autophagy. Deleting RIM15 attenuates invasive hyphal growth and triggers plant immunity; exogenous addition of α-ketoglutarate prevents these effects, while glucose addition only suppresses host defenses. Our results indicate that Rim15-dependent cycles of autophagic flux liberate α-ketoglutarate - via glutaminolysis - to reactivate TOR signaling and fuel biotrophic growth while conserving glucose for antioxidation-mediated host innate immunity suppression.
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Affiliation(s)
- Gang Li
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Ziwen Gong
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Nawaraj Dulal
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Margarita Marroquin-Guzman
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
- Bayer CropScience, Chesterfield, MO, USA
| | - Raquel O Rocha
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, CT, USA
| | - Michael Richter
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Richard A Wilson
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA.
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14
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Yan X, Tang B, Ryder LS, MacLean D, Were VM, Eseola AB, Cruz-Mireles N, Ma W, Foster AJ, Osés-Ruiz M, Talbot NJ. The transcriptional landscape of plant infection by the rice blast fungus Magnaporthe oryzae reveals distinct families of temporally co-regulated and structurally conserved effectors. THE PLANT CELL 2023; 35:1360-1385. [PMID: 36808541 PMCID: PMC10118281 DOI: 10.1093/plcell/koad036] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 05/04/2023]
Abstract
The rice blast fungus Magnaporthe oryzae causes a devastating disease that threatens global rice (Oryza sativa) production. Despite intense study, the biology of plant tissue invasion during blast disease remains poorly understood. Here we report a high-resolution transcriptional profiling study of the entire plant-associated development of the blast fungus. Our analysis revealed major temporal changes in fungal gene expression during plant infection. Pathogen gene expression could be classified into 10 modules of temporally co-expressed genes, providing evidence for the induction of pronounced shifts in primary and secondary metabolism, cell signaling, and transcriptional regulation. A set of 863 genes encoding secreted proteins are differentially expressed at specific stages of infection, and 546 genes named MEP (Magnaportheeffector protein) genes were predicted to encode effectors. Computational prediction of structurally related MEPs, including the MAX effector family, revealed their temporal co-regulation in the same co-expression modules. We characterized 32 MEP genes and demonstrate that Mep effectors are predominantly targeted to the cytoplasm of rice cells via the biotrophic interfacial complex and use a common unconventional secretory pathway. Taken together, our study reveals major changes in gene expression associated with blast disease and identifies a diverse repertoire of effectors critical for successful infection.
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Affiliation(s)
- Xia Yan
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Bozeng Tang
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Lauren S Ryder
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Dan MacLean
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Vincent M Were
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Alice Bisola Eseola
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Neftaly Cruz-Mireles
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Weibin Ma
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Andrew J Foster
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
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15
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Zhou L, Zhu T, Han S, Li S, Liu Y, Lin T, Qiao T. Changes in the Histology of Walnut ( Juglans regia L.) Infected with Phomopsis capsici and Transcriptome and Metabolome Analysis. Int J Mol Sci 2023; 24:ijms24054879. [PMID: 36902308 PMCID: PMC10003368 DOI: 10.3390/ijms24054879] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/06/2023] Open
Abstract
Phomopsis capsici (P. capsici) causes branch blight of walnuts, which leads to significant economic loss. The molecular mechanism behind the response of walnuts remains unknown. Paraffin sectioning and transcriptome and metabolome analyses were performed to explore the changes in tissue structure, gene expression, and metabolic processes in walnut after infection with P. capsici. We found that P. capsici caused serious damage to xylem vessels during the infestation of walnut branches, destroying the structure and function of the vessels and creating obstacles to the transport of nutrients and water to the branches. The transcriptome results showed that differentially expressed genes (DEGs) were mainly annotated in carbon metabolism and ribosomes. Further metabolome analyses verified the specific induction of carbohydrate and amino acid biosynthesis by P. capsici. Finally, association analysis was performed for DEGs and differentially expressed metabolites (DEMs), which focused on the synthesis and metabolic pathways of amino acids, carbon metabolism, and secondary metabolites and cofactors. Three significant metabolites were identified: succinic semialdehyde acid, fumaric acid, and phosphoenolpyruvic acid. In conclusion, this study provides data reference on the pathogenesis of walnut branch blight and direction for breeding walnut to enhance its disease resistance.
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16
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A secondary function of trehalose-6-phosphate synthase is required for resistance to oxidative and desiccation stress in Fusarium verticillioides. Fungal Biol 2023; 127:918-926. [PMID: 36906382 DOI: 10.1016/j.funbio.2023.01.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 12/12/2022] [Accepted: 01/20/2023] [Indexed: 01/22/2023]
Abstract
The disaccharide trehalose has long been recognized for its role as a stress solute, but in recent years some of the protective effects previously ascribed to trehalose have been suggested to arise from a function of the trehalose biosynthesis enzyme trehalose-6-phosphate (T6P) synthase that is distinct from its catalytic activity. In this study, we use the maize pathogenic fungus Fusarium verticillioides as a model to explore the relative contributions of trehalose itself and a putative secondary function of T6P synthase in protection against stress as well as to understand why, as shown in a previous study, deletion of the TPS1 gene coding for T6P synthase reduces pathogenicity against maize. We report that a TPS1-deletion mutant of F. verticillioides is compromised in its ability to withstand exposure to oxidative stress meant to simulate the oxidative burst phase of maize defense and experiences more ROS-induced lipid damage than the wild-type strain. Eliminating T6P synthase expression also reduces resistance to desiccation, but not resistance to phenolic acids. Expression of catalytically-inactive T6P synthase in the TPS1-deletion mutant leads to a partial rescue of the oxidative and desiccation stress-sensitive phenotypes, suggesting the importance of a T6P synthase function that is independent of its role in trehalose synthesis.
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17
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Wang M, Dean RA. Host induced gene silencing of Magnaporthe oryzae by targeting pathogenicity and development genes to control rice blast disease. FRONTIERS IN PLANT SCIENCE 2022; 13:959641. [PMID: 36035704 PMCID: PMC9403838 DOI: 10.3389/fpls.2022.959641] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
Rice blast disease caused by the hemi-biotrophic fungus Magnaporthe oryzae is the most destructive disease of rice world-wide. Traditional disease resistance strategies for the control of rice blast disease have not proved durable. HIGS (host induced gene silencing) is being developed as an alternative strategy. Six genes (CRZ1, PMC1, MAGB, LHS1, CYP51A, CYP51B) that play important roles in pathogenicity and development of M. oryzae were chosen for HIGS. HIGS vectors were transformed into rice calli through Agrobacterium-mediated transformation and T0, T1 and T2 generations of transgenic rice plants were generated. Except for PMC1 and LHS1, HIGS transgenic rice plants challenged with M. oryzae showed significantly reduced disease compared with non-silenced control plants. Following infection with M. oryzae of HIGS transgenic plants, expression levels of target genes were reduced as demonstrated by Quantitative RT-PCR. In addition, treating M. oryzae with small RNA derived from the target genes inhibited fungal growth. These findings suggest RNA silencing signals can be transferred from host to an invasive fungus and that HIGS has potential to generate resistant rice against M. oryzae.
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18
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Ryder LS, Cruz-Mireles N, Molinari C, Eisermann I, Eseola AB, Talbot NJ. The appressorium at a glance. J Cell Sci 2022; 135:276040. [PMID: 35856284 DOI: 10.1242/jcs.259857] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Many plant pathogenic fungi have the capacity to infect their plant hosts using specialised cells called appressoria. These structures act as a gateway between the fungus and host, allowing entry to internal tissues. Appressoria apply enormous physical force to rupture the plant surface, or use a battery of enzymes to digest the cuticle and plant cell wall. Appressoria also facilitate focal secretion of effectors at the point of plant infection to suppress plant immunity. These infection cells develop in response to the physical characteristics of the leaf surface, starvation stress and signals from the plant. Appressorium morphogenesis has been linked to septin-mediated reorganisation of F-actin and microtubule networks of the cytoskeleton, and remodelling of the fungal cell wall. In this Cell Science at a Glance and accompanying poster, we highlight recent advances in our understanding of the mechanisms of appressorium-mediated infection, and compare development on the leaf surface to the biology of invasive growth by pathogenic fungi. Finally, we outline key gaps in our current knowledge of appressorium cell biology.
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Affiliation(s)
- Lauren S Ryder
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Neftaly Cruz-Mireles
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Camilla Molinari
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Iris Eisermann
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Alice B Eseola
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
| | - Nicholas J Talbot
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich NR4 7UH, UK
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19
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Li C, Xu D, Hu M, Zhang Q, Xia Y, Jin K. MaNCP1, a C2H2 Zinc Finger Protein, Governs the Conidiation Pattern Shift through Regulating the Reductive Pathway for Nitric Oxide Synthesis in the Filamentous Fungus Metarhizium acridum. Microbiol Spectr 2022; 10:e0053822. [PMID: 35536030 PMCID: PMC9241723 DOI: 10.1128/spectrum.00538-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 04/19/2022] [Indexed: 12/19/2022] Open
Abstract
Asexual sporulation is the most common reproduction mode of fungi. Most filamentous fungi have two conidiation patterns, normal conidiation and microcycle conidiation, which may be regulated by nutritional conditions. Nitrogen source can affect the fungal conidiation pattern, but the regulatory mechanism is not fully understood. In this study, we report a C2H2 zinc finger protein, MaNCP1, which has typical transcription factor characteristics and is screened from the subtractive library regulated by nitrate in the entomopathogenic fungus Metarhizium acridum. MaNCP1 and its N-terminal play critical roles in the conidiation pattern shift. Further study shows that MaNCP1 interacts with MaNmrA, which also contributes to the conidiation pattern shift and is involved in the reductive pathway of nitric oxide (NO) synthesis. Intriguingly, the conidiation pattern of the MaNCP1-disruption strain (ΔMaNCP1) can be restored to microcycle conidiation when grown on the microcycle conidiation medium, SYA, supplemented with NO donor or overexpressing MaNmrA in ΔMaNCP1. Here, we reveal that MaNCP1 governs the conidiation pattern shift through regulating the reductive synthesis of NO by physically targeting MaNmrA in M. acridum. This work provides new mechanistic insights into how changes in nitrogen utilization are linked to the regulation of fungal morphological changes. IMPORTANCE Fungal conidia play important roles in the response to environmental stimuli and evasion of the host immune system. The nitrogen source is one of the main factors affecting shifts in fungal conidiation patterns, but the regulatory mechanism involved is not fully understood. In this work, we report that the C2H2 zinc finger protein, MaNCP1, governs the conidiation pattern shift in M. acridum by targeting the MaNmrA gene, thereby altering the regulation of the reductive pathway for NO synthesis. This work provides further insights into how the nutritional environment can regulate the morphogenesis of filamentous fungi.
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Affiliation(s)
- Chaochuang Li
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, People’s Republic of China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, People’s Republic of China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, People’s Republic of China
| | - Dingxiang Xu
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, People’s Republic of China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, People’s Republic of China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, People’s Republic of China
| | - Meiwen Hu
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, People’s Republic of China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, People’s Republic of China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, People’s Republic of China
| | - Qipei Zhang
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, People’s Republic of China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, People’s Republic of China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, People’s Republic of China
| | - Yuxian Xia
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, People’s Republic of China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, People’s Republic of China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, People’s Republic of China
| | - Kai Jin
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, People’s Republic of China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, People’s Republic of China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, People’s Republic of China
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H3K4 Methyltransferase CfSet1 Is Required for Development and Pathogenesis in Colletotrichum fructicola. J Fungi (Basel) 2022; 8:jof8040363. [PMID: 35448594 PMCID: PMC9025643 DOI: 10.3390/jof8040363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/24/2022] [Accepted: 03/31/2022] [Indexed: 12/04/2022] Open
Abstract
Tea-oil tree (Camellia oleifera Abel.) is a unique woody edible oil species in China. Anthracnose is the common disease of Ca. oleifera, which affected the production and brought huge economic losses. Colletotrichum fructicola is the dominant pathogen causing Ca. oleifera anthracnose. The gene CfSET1 was deleted and its roles in development and pathogenicity of C. fructicola were studied. Our results show that this protein participated in the growth, conidiation, appressorium formation, and pathogenicity of this fungal pathogen. Our results help us understand the mechanisms of pathogenesis in C. fructicola and suggest CfSet1 as a potential target for the development of new fungicide.
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Wang X, Lu D, Tian C. Mucin Msb2 cooperates with the transmembrane protein Sho1 in various plant surface signal sensing and pathogenic processes in the poplar anthracnose fungus Colletotrichum gloeosporioides. MOLECULAR PLANT PATHOLOGY 2021; 22:1553-1573. [PMID: 34414655 PMCID: PMC8578833 DOI: 10.1111/mpp.13126] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 06/22/2021] [Accepted: 07/29/2021] [Indexed: 05/11/2023]
Abstract
Colletotrichum gloeosporioides is a hemibiotrophic ascomycete fungus that causes anthracnose on numerous plants worldwide and forms a specialized infection structure known as an appressorium in response to various plant surface signals. However, the associated mechanism of host surface signal recognition remains unclear. In the present study, three putative sensors, namely the mucin Msb2, the membrane sensor protein Sho1, and the G-protein-coupled receptor Pth11, were identified and characterized. The results showed that CgMsb2 plays a major role in the recognition of various host surface signals; deletion of CgMsb2 resulted in significant defects in appressorium formation, appressorium penetration, cellophane membrane penetration, and pathogenicity. CgSho1 plays a minor role and together with CgMsb2 cooperatively regulates host signal recognition, cellophane membrane penetration, and pathogenicity; deletion of CgSho1 resulted in an expansion defect of infection hyphae. Deletion of CgPth11 in wildtype, ΔCgMsb2, and ΔCgSho1 strains only resulted in a slight defect in appressorium formation at the early stage, and CgPth11 was dispensable for penetration and pathogenicity. However, exogenous cAMP failed to restore the defect of appressorium formation in ΔCgPth11 at the early stage. CgMsb2 contributed to the phosphorylation of the mitogen-activated protein kinase CgMk1, which is essential for infection-associated functions, while CgSho1 was unable to activate CgMk1 alone but rather cooperated with CgMsb2 to activate CgMk1. These data suggest that CgMsb2 contributes to the activation of CgMk1 and has overlapping functions with CgSho1 in plant surface sensing, appressorium formation, and pathogenicity.
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Affiliation(s)
- Xiaolian Wang
- The Key Laboratory for Silviculture and Conservation of Ministry of EducationCollege of ForestryBeijing Forestry UniversityBeijingChina
| | - Dongxiao Lu
- The Key Laboratory for Silviculture and Conservation of Ministry of EducationCollege of ForestryBeijing Forestry UniversityBeijingChina
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of EducationCollege of ForestryBeijing Forestry UniversityBeijingChina
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22
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Chen Y, Cao Y, Gai Y, Ma H, Zhu Z, Chung KR, Li H. Genome-Wide Identification and Functional Characterization of GATA Transcription Factor Gene Family in Alternaria alternata. J Fungi (Basel) 2021; 7:jof7121013. [PMID: 34946995 PMCID: PMC8706292 DOI: 10.3390/jof7121013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 12/19/2022] Open
Abstract
In the present study, we identified six GATA transcription factors (AaAreA, AaAreB, AaLreA, AaLreB, AaNsdD, and AaSreA) and characterized their functions in response to environmental stress and virulence in the tangerine pathotype of Alternaria alternata. The targeted gene knockout of each of the GATA-coding genes decreased the growth to varying degrees. The mutation of AaAreA, AaAreB, AaLreB, or AaNsdD decreased the conidiation. All the GATA transcription factors were found to be required for tolerance to cumyl hydroperoxide and tert-butyl-hydroperoxide (oxidants) and Congo red (a cell-wall-destructing agent). Pathogenicity assays assessed on detached citrus leaves revealed that mutations of AaAreA, AaLreA, AaLreB, or AaNsdD significantly decreased the fungal virulence. A comparative transcriptome analysis between the ∆AreA mutant and the wild-type strain revealed that the inactivation of AaAreA led to alterations in the expression of genes involved in a number of biological processes, including oxidoreductase activity, amino acid metabolism, and secondary metabolite biogenesis. Taken together, our findings revealed that GATA-coding genes play diverse roles in response to environmental stress and are important regulators involved in fungal development, conidiation, ROS detoxification, as well as pathogenesis. This study, for the first time, systemically underlines the critical role of GATA transcription factors in response to environmental stress and virulence in A. alternata.
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Affiliation(s)
- Yanan Chen
- The Key Laboratory of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture and Rural Affairs, The Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.C.); (Y.C.); (Y.G.); (H.M.); (Z.Z.)
| | - Yingzi Cao
- The Key Laboratory of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture and Rural Affairs, The Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.C.); (Y.C.); (Y.G.); (H.M.); (Z.Z.)
| | - Yunpeng Gai
- The Key Laboratory of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture and Rural Affairs, The Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.C.); (Y.C.); (Y.G.); (H.M.); (Z.Z.)
| | - Haijie Ma
- The Key Laboratory of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture and Rural Affairs, The Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.C.); (Y.C.); (Y.G.); (H.M.); (Z.Z.)
- School of Agriculture and Food Sciences, Zhejiang Agriculture & Forestry University, Hangzhou 311300, China
| | - Zengrong Zhu
- The Key Laboratory of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture and Rural Affairs, The Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.C.); (Y.C.); (Y.G.); (H.M.); (Z.Z.)
- Hainan Institute, Zhejiang University, Sanya 572000, China
| | - Kuang-Ren Chung
- Department of Plant Pathology, College of Agriculture and Natural Resources, National Chung-Hsing University, Taichung 40227, Taiwan;
| | - Hongye Li
- The Key Laboratory of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture and Rural Affairs, The Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (Y.C.); (Y.C.); (Y.G.); (H.M.); (Z.Z.)
- Correspondence: ; Tel.: +86-13634190823
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MaNmrA, a Negative Transcription Regulator in Nitrogen Catabolite Repression Pathway, Contributes to Nutrient Utilization, Stress Resistance, and Virulence in Entomopathogenic Fungus Metarhizium acridum. BIOLOGY 2021; 10:biology10111167. [PMID: 34827160 PMCID: PMC8615229 DOI: 10.3390/biology10111167] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 12/15/2022]
Abstract
Simple Summary Nutrient metabolism is closely related to the growth, development, and pathogenicity of pathogenic fungi. The nitrogen catabolite repression (NCR) pathway is a well-known fungal nitrogen source regulation path, in which NmrA plays an important regulatory role. Here, we reported a negative regulatory protein MaNmrA, the NmrA homologous protein, in the entomopathogenic fungus Metarhizium acridum, and found that it played important roles in carbon and nitrogen metabolism, growth, stress tolerance, and virulence of M. acridum. Our work will provide a theoretical basis for further exploring the functions of NCR pathway related genes in entomopathogenic fungi. Abstract The NCR pathway plays an important regulatory role in the nitrogen metabolism of filamentous fungi. NmrA, a central negative regulatory protein in the NCR pathway and a key factor in sensing to the carbon metabolism, plays important roles in pathogenic fungal nutrition metabolism. In this study, we characterized the functions of MaNmrA in the insect pathogenic fungus M. acridum. Multiple sequence alignments found that the conserved domain (NAD/NADP binding domain) of MaNmrA was highly conservative with its homologues proteins. Deletion of MaNmrA improved the utilization of multiple carbon sources (such as glucose, mannose, sucrose, and trehalose) and non-preferred nitrogen sources (such as NaNO3 and urea), significantly delayed the conidial germination rate and reduced the conidial yield. The MaNmrA-disruption strain (ΔMaNmrA) significantly decreased tolerances to UV-B and heat-shock, and it also increased the sensitivity to the hypertonic substance sorbitol, oxygen stress substance H2O2, and cell wall destroyer calcofluor white, indicating that loss of MaNmrA affected cell wall integrity, tolerances to hypertonic and oxidative stress. Bioassays demonstrated that disruption of MaNmrA decreased the virulence in both topical inoculation and intrahemocoel injection tests. Further studies revealed that the appressorium formation, turgor pressure, and colonization in hemolymph were significantly reduced in the absence of MaNmrA. Our work will deepen the functional cognition of MaNmrA and make a contribution to the study of its homologous proteins.
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24
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Osés-Ruiz M, Cruz-Mireles N, Martin-Urdiroz M, Soanes DM, Eseola AB, Tang B, Derbyshire P, Nielsen M, Cheema J, Were V, Eisermann I, Kershaw MJ, Yan X, Valdovinos-Ponce G, Molinari C, Littlejohn GR, Valent B, Menke FLH, Talbot NJ. Appressorium-mediated plant infection by Magnaporthe oryzae is regulated by a Pmk1-dependent hierarchical transcriptional network. Nat Microbiol 2021; 6:1383-1397. [PMID: 34707224 DOI: 10.1038/s41564-021-00978-w] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 09/09/2021] [Indexed: 01/18/2023]
Abstract
Rice blast is a devastating disease caused by the fungal pathogen Magnaporthe oryzae that threatens rice production around the world. The fungus produces a specialized infection cell, called the appressorium, that enables penetration through the plant cell wall in response to surface signals from the rice leaf. The underlying biology of plant infection, including the regulation of appressorium formation, is not completely understood. Here we report the identification of a network of temporally coregulated transcription factors that act downstream of the Pmk1 mitogen-activated protein kinase pathway to regulate gene expression during appressorium-mediated plant infection. We show that this tiered regulatory mechanism involves Pmk1-dependent phosphorylation of the Hox7 homeobox transcription factor, which regulates genes associated with induction of major physiological changes required for appressorium development-including cell-cycle control, autophagic cell death, turgor generation and melanin biosynthesis-as well as controlling a additional set of virulence-associated transcription factor-encoding genes. Pmk1-dependent phosphorylation of Mst12 then regulates gene functions involved in septin-dependent cytoskeletal re-organization, polarized exocytosis and effector gene expression, which are necessary for plant tissue invasion. Identification of this regulatory cascade provides new potential targets for disease intervention.
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Affiliation(s)
- Míriam Osés-Ruiz
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, Norwich, UK.
| | - Neftaly Cruz-Mireles
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, Norwich, UK
| | | | | | - Alice Bisola Eseola
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Bozeng Tang
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Paul Derbyshire
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, Norwich, UK
| | | | | | - Vincent Were
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Iris Eisermann
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, Norwich, UK
| | | | - Xia Yan
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Guadalupe Valdovinos-Ponce
- Department of Plant Pathology, Kansas State University, Manhattan, KS, USA.,Department of Plant Pathology, Colegio de Postgraduados, Montecillo, Texcoco, Mexico
| | - Camilla Molinari
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, Norwich, UK
| | - George R Littlejohn
- School of Biosciences, University of Exeter, Exeter, UK.,Department of Biological and Marine Sciences, University of Plymouth, Drakes Circus, Plymouth, UK
| | - Barbara Valent
- Department of Plant Pathology, Kansas State University, Manhattan, KS, USA
| | - Frank L H Menke
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Nicholas J Talbot
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, Norwich, UK.
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Trehalose Phosphate Synthase Complex-Mediated Regulation of Trehalose 6-Phosphate Homeostasis Is Critical for Development and Pathogenesis in Magnaporthe oryzae. mSystems 2021; 6:e0046221. [PMID: 34609170 PMCID: PMC8547450 DOI: 10.1128/msystems.00462-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Trehalose biosynthesis pathway is a potential target for antifungal drug development, and trehalose 6-phosphate (T6P) accumulation is widely known to have toxic effects on cells. However, how organisms maintain a safe T6P level and cope with its cytotoxicity effects when accumulated have not been reported. Herein, we unveil the mechanism by which the rice blast fungus Magnaporthe oryzae avoids T6P accumulation and the genetic and physiological adjustments it undergoes to self-adjust the metabolite level when it is unavoidably accumulated. We found that T6P accumulation leads to defects in fugal development and pathogenicity. The accumulated T6P impairs cell wall assembly by disrupting actin organization. The disorganization of actin impairs the distribution of chitin synthases, thereby disrupting cell wall polymer distribution. Additionally, accumulation of T6P compromise energy metabolism. M. oryzae was able to overcome the effects of T6P accumulation by self-mutation of its MoTPS3 gene at two different mutation sites. We further show that mutation of MoTPS3 suppresses MoTps1 activity to reduce the intracellular level of T6P and partially restore ΔMotps2 defects. Overall, our results provide insights into the cytotoxicity effects of T6P accumulation and uncover a spontaneous mutation strategy to rebalance accumulated T6P in M. oryzae. IMPORTANCEM. oryzae, the causative agent of the rice blast disease, threatens rice production worldwide. Our results revealed that T6P accumulation, caused by the disruption of MoTPS2, has toxic effects on fugal development and pathogenesis in M. oryzae. The accumulated T6P impairs the distribution of cell wall polymers via actin organization and therefore disrupts cell wall structure. M. oryzae uses a spontaneous mutation to restore T6P cytotoxicity. Seven spontaneous mutation sites were found, and a mutation in MoTPS3 was further identified. The spontaneous mutation in MoTPS3 can partially rescue ΔMotps2 defects by suppressing MoTps1 activity to alleviate T6P cytotoxicity. This study provides clear evidence for better understanding of T6P cytotoxicity and how the fungus protects itself from T6P’s toxic effects when it has accumulated to severely high levels.
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26
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Wang X, Lu D, Tian C. Analysis of melanin biosynthesis in the plant pathogenic fungus Colletotrichum gloeosporioides. Fungal Biol 2021; 125:679-692. [PMID: 34420695 DOI: 10.1016/j.funbio.2021.04.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 04/04/2021] [Accepted: 04/19/2021] [Indexed: 11/25/2022]
Abstract
Melanin is recognized as a dark pigment that can protect fungi from the harm of environmental stresses. To investigate what roles of melanin played in the pathogenicity and development of Colletotrichum gloeosporioides, a causal agent of poplar anthracnose, genes encoding a transcription factor CgCmr1 and a polyketide synthase CgPks1 were isolated as the ortholog of Magnaporthe oryzae Pig1 and Pks1 respectively. Deletion of CgCmr1 or CgPks1 resulted in melanin-deficient fungal colony. The ΔCgPks1 mutant showed no melanin accumulation in appressoria, and lack of CgCmr1 also resulted in the delayed and decreased melanization of appressoria. In addition, the turgor pressure of the appressorium was lower in ΔCgPks1 and ΔCgCmr1 than in the wild-type (WT). However, DHN melanin was not a vital factor for virulence in C. gloeosporioides. Moreover, deletion of CgCmr1 and CgPks1 resulted in the hypersensitivity to hydrogen peroxide (H2O2) oxidative stress but not to other abiotic stresses. Collectively, these results suggest that CgCmr1 and CgPks1 play an important role in DHN melanin biosynthesis, and melanin was not an essential factor in penetration and pathogenicity in C. gloeosporioides. The data presented in this study will facilitate future evaluations of the melanin biosynthetic pathway and development in filamentous fungi.
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Affiliation(s)
- Xiaolian Wang
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Dongxiao Lu
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China.
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27
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Tang C, Li W, Klosterman SJ, Wang Y. Transcriptome Variations in Verticillium dahliae in Response to Two Different Inorganic Nitrogen Sources. Front Microbiol 2021; 12:712701. [PMID: 34394062 PMCID: PMC8355529 DOI: 10.3389/fmicb.2021.712701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 07/01/2021] [Indexed: 11/16/2022] Open
Abstract
The fungus Verticillium dahliae causes vascular wilt disease on hundreds of plant species. The main focus of the research to control this fungus has been aimed at infection processes such as penetration peg formation and effector secretion, but the ability of the fungus to acquire and utilize nutrients are often overlooked and may hold additional potential to formulate new disease control approaches. Little is known about the molecular mechanisms of nitrogen acquisition and assimilation processes in V. dahliae. In this present study, RNA sequencing and gene expression analysis were used to examine differentially expressed genes in response to the different nitrogen sources, nitrate and ammonium, in V. dahliae. A total of 3244 and 2528 differentially expressed genes were identified in response to nitrate and ammonium treatments, respectively. The data indicated nitrate metabolism requires additional energy input while ammonium metabolism is accompanied by reductions in particular cellular processes. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses of DEGs during nitrate metabolism revealed that many of the genes encoded those involved in protein biosynthetic and metabolic processes, especially ribosome and RNA polymerase biosynthesis, but also other processes including transport and organonitrogen compound metabolism. Analysis of DEGs in the ammonium treatment indicated that cell cycle, oxidoreductase, and certain metabolic activities were reduced. In addition, DEGs participating in the utilization of both nitrate and ammonium were related to L-serine biosynthesis, energy-dependent multidrug efflux pump activity, and glycerol transport. We further showed that the mutants of three differentially expressed transcription factors (VdMcm1, VdHapX, and VDAG_08640) exhibited abnormal phenotypes under nitrate and ammonium treatment compared with the wild type strain. Deletion of VdMcm1 displayed slower growth when utilizing both nitrogen sources, while deletion of VdHapX and VDAG_08640 only affected nitrate metabolism, inferring that nitrogen assimilation required regulation of bZIP transcription factor family and participation of cell cycle. Taken together, our findings illustrate the convergent and distinctive regulatory mechanisms between preferred (ammonium) and alternative nitrogen (nitrate) metabolism at the transcriptome level, leading to better understanding of inorganic nitrogen metabolism in V. dahliae.
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Affiliation(s)
- Chen Tang
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Wenwen Li
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Steven J Klosterman
- Agricultural Research Service, United States Department of Agriculture, Salinas, CA, United States
| | - Yonglin Wang
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
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28
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John E, Singh KB, Oliver RP, Tan K. Transcription factor control of virulence in phytopathogenic fungi. MOLECULAR PLANT PATHOLOGY 2021; 22:858-881. [PMID: 33973705 PMCID: PMC8232033 DOI: 10.1111/mpp.13056] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 03/02/2021] [Accepted: 03/04/2021] [Indexed: 05/12/2023]
Abstract
Plant-pathogenic fungi are a significant threat to economic and food security worldwide. Novel protection strategies are required and therefore it is critical we understand the mechanisms by which these pathogens cause disease. Virulence factors and pathogenicity genes have been identified, but in many cases their roles remain elusive. It is becoming increasingly clear that gene regulation is vital to enable plant infection and transcription factors play an essential role. Efforts to determine their regulatory functions in plant-pathogenic fungi have expanded since the annotation of fungal genomes revealed the ubiquity of transcription factors from a broad range of families. This review establishes the significance of transcription factors as regulatory elements in plant-pathogenic fungi and provides a systematic overview of those that have been functionally characterized. Detailed analysis is provided on regulators from well-characterized families controlling various aspects of fungal metabolism, development, stress tolerance, and the production of virulence factors such as effectors and secondary metabolites. This covers conserved transcription factors with either specialized or nonspecialized roles, as well as recently identified regulators targeting key virulence pathways. Fundamental knowledge of transcription factor regulation in plant-pathogenic fungi provides avenues to identify novel virulence factors and improve our understanding of the regulatory networks linked to pathogen evolution, while transcription factors can themselves be specifically targeted for disease control. Areas requiring further insight regarding the molecular mechanisms and/or specific classes of transcription factors are identified, and direction for future investigation is presented.
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Affiliation(s)
- Evan John
- Centre for Crop and Disease ManagementCurtin UniversityBentleyWestern AustraliaAustralia
- School of Molecular and Life SciencesCurtin UniversityBentleyWestern AustraliaAustralia
| | - Karam B. Singh
- Agriculture and FoodCommonwealth Scientific and Industrial Research OrganisationFloreatWestern AustraliaAustralia
| | - Richard P. Oliver
- School of Molecular and Life SciencesCurtin UniversityBentleyWestern AustraliaAustralia
| | - Kar‐Chun Tan
- Centre for Crop and Disease ManagementCurtin UniversityBentleyWestern AustraliaAustralia
- School of Molecular and Life SciencesCurtin UniversityBentleyWestern AustraliaAustralia
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A Novel Nitrogen and Carbon Metabolism Regulatory Cascade Is Implicated in Entomopathogenicity of the Fungus Metarhizium robertsii. mSystems 2021; 6:e0049921. [PMID: 34156296 PMCID: PMC8269237 DOI: 10.1128/msystems.00499-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
The entomopathogenic fungus Metarhizium robertsii can switch among parasitic, saprophytic, and symbiotic lifestyles in response to changing nutritional conditions, which is attributed to its extremely versatile metabolism. Here, we found that the Fus3–mitogen-activated protein kinase (MAPK) and the transcription factor regulator of nutrient selection 1 (RNS1) constitute a novel fungal cascade that regulates the degradation of insect cuticular lipids, proteins, and chitin to obtain nutrients for hyphal growth and enter the insect hemocoel for subsequent colonization. On the insect cuticle, Fus3-MAPK physically contacts and phosphorylates RNS1, which facilitates the entry of RNS1 into nuclei. The phosphorylated RNS1 binds to the DNA motif BM2 (ACCAGAC) in its own promoter to self-induce expression, which then activates the expression of genes for degrading cuticular proteins, chitin, and lipids. We further found that the Fus3-MAPK/RNS1 cascade also activates genes for utilizing complex and less-favored nitrogen and carbon sources (casein, colloid chitin, and hydrocarbons) that were not derived from insects, which is repressed by favored organic carbon and nitrogen nutrients, including glucose and glutamine. In conclusion, we discovered a novel regulatory cascade that controls fungal nitrogen and carbon metabolism and is implicated in the entomopathogenicity of M. robertsii. IMPORTANCE Penetration of the cuticle, the first physical barrier to pathogenic fungi, is the prerequisite for fungal infection of insects. In the entomopathogenic fungus Metarhizium robertsii, we found that the Fus3–mitogen-activated protein kinase (MAPK) and the transcription factor regulator of nutrient selection 1 (RNS1) constitute a novel cascade that controls cuticle penetration by regulating degradation of cuticular lipids, proteins, and chitin to obtain nutrients for hyphal growth and entry into the insect hemocoel. In addition, during saprophytic growth, the Fus3-MAPK/RNS1 cascade also activates utilization of complex and less-favored carbon and nitrogen sources that are not derived from insects. The homologs of Fus3-MAPK and RNS1 are widely found in ascomycete filamentous fungi, including saprophytes and pathogens with diverse hosts, suggesting that the regulation of utilization of nitrogen and carbon sources by the Fus3-MAPK/RNS1 cascade could be widespread. Our work provides significant insights into regulation of carbon and nitrogen metabolism in fungi and fungal pathogenesis in insects.
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Zhu Q, Chen L, Chen T, Xu Q, He T, Wang Y, Deng X, Zhang S, Pan Y, Jin A. Integrated transcriptome and metabolome analyses of biochar-induced pathways in response to Fusarium wilt infestation in pepper. Genomics 2021; 113:2085-2095. [PMID: 33895283 DOI: 10.1016/j.ygeno.2021.04.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 03/13/2021] [Accepted: 04/19/2021] [Indexed: 11/25/2022]
Abstract
The present study used soils contaminated with Fusarium oxysporum f. sp. capsici (CCS) and CCS amended with bamboo biochar (CCS + BC) to grow the pepper variety Qujiao No.1. The physiological performance, and transcriptome and metabolome profiling in leaf (L) and fruit (F) of Qujiao No.1 were conducted. Application of biochar improved soil properties, pepper plant nutrition and increased activities of enzymes related to pest/disease resistance, leading to superior physiological performance and lesser F. wilt disease incidence than plants from CCS. Most of the differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) were involved in protein processing in endoplasmic reticulum (fruit), plant pathogen interaction (fruit), photosynthesis (leaf), phenylpropanoid biosynthesis (both tissues) and metabolic pathways (both tissues). Biochar improved plant photosynthesis, enhanced the immune system, energy production and increased stress signaling pathways. Overall, our results provide evidence of a number of pathways induced by biochar in pepper regulating its response to F. wilt disease.
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Affiliation(s)
- Qianggen Zhu
- College of Ecology, Lishui University, Lishui, Zhejiang 323000, China
| | - Limin Chen
- Integrated Plant Protection Center, Lishui Academy of Agricultural and Forestry Sciences, 827 Liyang Stress, Lishui, Zhejiang 323000, China; State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agricultural and Forestry University, Fuzhou 350002, China
| | - Tingting Chen
- College of Ecology, Lishui University, Lishui, Zhejiang 323000, China
| | - Qian Xu
- College of Ecology, Lishui University, Lishui, Zhejiang 323000, China
| | - Tianjun He
- Integrated Plant Protection Center, Lishui Academy of Agricultural and Forestry Sciences, 827 Liyang Stress, Lishui, Zhejiang 323000, China
| | - Yikun Wang
- College of Ecology, Lishui University, Lishui, Zhejiang 323000, China
| | - Xianjun Deng
- College of Ecology, Lishui University, Lishui, Zhejiang 323000, China
| | - Sihai Zhang
- College of Ecology, Lishui University, Lishui, Zhejiang 323000, China
| | - Yiming Pan
- Integrated Plant Protection Center, Lishui Academy of Agricultural and Forestry Sciences, 827 Liyang Stress, Lishui, Zhejiang 323000, China
| | - Aiwu Jin
- College of Ecology, Lishui University, Lishui, Zhejiang 323000, China; Integrated Plant Protection Center, Lishui Academy of Agricultural and Forestry Sciences, 827 Liyang Stress, Lishui, Zhejiang 323000, China.
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CgEnd3 Regulates Endocytosis, Appressorium Formation, and Virulence in the Poplar Anthracnose Fungus Colletotrichum gloeosporioides. Int J Mol Sci 2021; 22:ijms22084029. [PMID: 33919762 PMCID: PMC8103510 DOI: 10.3390/ijms22084029] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/02/2021] [Accepted: 04/03/2021] [Indexed: 01/23/2023] Open
Abstract
The hemibiotrophic ascomycete fungus Colletotrichum gloeosporioides is the causal agent of anthracnose on numerous plants, and it causes considerable economic losses worldwide. Endocytosis is an essential cellular process in eukaryotic cells, but its roles in C. gloeosporioides remain unknown. In our study, we identified an endocytosis-related protein, CgEnd3, and knocked it out via polyethylene glycol (PEG)-mediated protoplast transformation. The lack of CgEnd3 resulted in severe defects in endocytosis. C. gloeosporioides infects its host through a specialized structure called appressorium, and ΔCgEnd3 showed deficient appressorium formation, melanization, turgor pressure accumulation, penetration ability of appressorium, cellophane membrane penetration, and pathogenicity. CgEnd3 also affected oxidant adaptation and the expression of core effectors during the early stage of infection. CgEnd3 contains one EF hand domain and four calcium ion-binding sites, and it is involved in calcium signaling. A lack of CgEnd3 changed the responses to cell-wall integrity agents and fungicide fludioxonil. However, CgEnd3 regulated appressorium formation and endocytosis in a calcium signaling-independent manner. Taken together, these results demonstrate that CgEnd3 plays pleiotropic roles in endocytosis, calcium signaling, cell-wall integrity, appressorium formation, penetration, and pathogenicity in C. gloeosporioides, and it suggests that CgEnd3 or endocytosis-related genes function as promising antifungal targets.
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Yan ZY, Zhao MR, Huang CY, Zhang LJ, Zhang JX. Trehalose alleviates high-temperature stress in Pleurotus ostreatus by affecting central carbon metabolism. Microb Cell Fact 2021; 20:82. [PMID: 33827585 PMCID: PMC8028756 DOI: 10.1186/s12934-021-01572-9] [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: 08/04/2020] [Accepted: 03/26/2021] [Indexed: 11/17/2022] Open
Abstract
Background Trehalose, an intracellular protective agent reported to mediate defense against many stresses, can alleviate high-temperature-induced damage in Pleurotus ostreatus. In this study, the mechanism by which trehalose relieves heat stress was explored by the addition of exogenous trehalose and the use of trehalose-6-phosphate synthase 1 (tps1) overexpression transformants. Results The results suggested that treatment with exogenous trehalose or overexpression of tps1 alleviated the accumulation of lactic acid under heat stress and downregulated the expression of the phosphofructokinase (pfk) and pyruvate kinase (pk) genes, suggesting an ameliorative effect of trehalose on the enhanced glycolysis in P. ostreatus under heat stress. However, the upregulation of hexokinase (hk) gene expression by trehalose indicated the involvement of the pentose phosphate pathway (PPP) in heat stress resistance. Moreover, treatment with exogenous trehalose or overexpression of tps1 increased the gene expression level and enzymatic activity of glucose-6-phosphate dehydrogenase (g6pdh) and increased the production of both the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione (GSH), confirming the effect of trehalose on alleviating oxidative damage by enhancing PPP in P. ostreatus under heat stress. Furthermore, treatment with exogenous trehalose or overexpression of tps1 ameliorated the decrease in the oxygen consumption rate (OCR) caused by heat stress, suggesting a relationship between trehalose and mitochondrial function under heat stress. Conclusions Trehalose alleviates high-temperature stress in P. ostreatus by inhibiting glycolysis and stimulating PPP activity. This study may provide further insights into the heat stress defense mechanism of trehalose in edible fungi from the perspective of intracellular metabolism. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01572-9.
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Affiliation(s)
- Zhi-Yu Yan
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, Beijing, 100081, China
| | - Meng-Ran Zhao
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, Beijing, 100081, China
| | - Chen-Yang Huang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, Beijing, 100081, China
| | - Li-Jiao Zhang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, Beijing, 100081, China
| | - Jin-Xia Zhang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China. .,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, Beijing, 100081, China.
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Wang X, Lu D, Tian C. Mitogen-activated protein kinase cascade CgSte50-Ste11-Ste7-Mk1 regulates infection-related morphogenesis in the poplar anthracnose fungus Colletotrichum gloeosporioides. Microbiol Res 2021; 248:126748. [PMID: 33752111 DOI: 10.1016/j.micres.2021.126748] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 11/28/2022]
Abstract
The hemibiotrophic pathogen Colletotrichum gloeosporioides is the causal agent of poplar anthracnose and causes considerable economic losses. This fungus infects its host through a specialized structure called an appressorium. In a previous study, we demonstrated that the mitogen-activated protein kinase (MAPK) CgMk1 plays a critical role in appressorium formation and pathogenicity. In this study, we identified three upstream components of CgMk1, the putative adaptor protein CgSte50, MAPKKK CgSte11, and MAPKK CgSte7, and showed that CgSte50, CgSte11, and CgSte7 positively regulate the phosphorylation of CgMk1. Deletion of CgSte50, CgSte11, and CgSte7 resulted in the loss of appressorium formation, penetration of the cellophane membrane, invasive growth and pathogenicity, similar to the defects observed in the CgMk1 mutant. CgSte50, CgSte11, CgSte7 and CgMk1 were also required for polarity during conidial germination. At the initial stage of appressorium formation, the accumulation of reactive oxygen species (ROS) was altered in the CgSte50, CgSte11, CgSte7 and CgMk1 deletion mutants compared with that in wild type (WT). Furthermore, the CgSte50, CgSte11, CgSte7 and CgMk1 deletion mutants manifested pleiotropic defects during vegetative growth; all mutants exhibited albino colonies, and the aerial hyphae had reduced hydrophobicity. In the mutants, autolysis was detected at the colony edge, and septum formation in the hyphae was elevated compared with that in the WT hyphae. Moreover, deletion of CgSte50, CgSte11, CgSte7 and CgMk1 affected vegetative growth under nitrogen-limiting and osmotic stress conditions. CgSte50, CgSte11, and CgSte7 but not CgMk1 were required for the oxidative stress response. Taken together, these results indicate that the CgMk1 MAPK cascade plays vital roles in various important functions in C. gloeosporioides.
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Affiliation(s)
- Xiaolian Wang
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Dongxiao Lu
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China.
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Yoshida H, Tanaka C. An arabinose-induced enhancement of asexual reproduction and concomitant changes in metabolic state in the filamentous fungus Bipolaris maydis. MICROBIOLOGY-SGM 2021; 167. [PMID: 33555250 DOI: 10.1099/mic.0.001009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
l-Arabinose, a major constituent pentose of plant cell-wall polysaccharides, has been suggested to be a less preferred carbon source for fungi but to be a potential signalling molecule that can cause distinct genome-wide transcriptional changes in fungal cells. Here, we explore the possibility that this unique pentose influences the morphological characteristics of the phytopathogenic fungus Bipolaris maydis strain HITO7711. When grown on plate media under different sugar conditions, the mycelial dry weight of cultures on l-arabinose was as low as that with no sugar, suggesting that l-arabinose does not substantially contribute to vegetative growth. However, the intensity of conidiation on l-arabinose was comparable to or even higher than that on d-glucose and on d-xylose, in contrast to the poor conidiation under the no-sugar condition. To explore the physiological basis of the passive growth and active conidiation on l-arabinose, we next investigated cellular responses of the fungus to these sugar conditions. Transcriptional analysis of genes related to carbohydrate metabolism showed that l-arabinose stimulates carbohydrate utilization through the hexose monophosphate shunt (HMP shunt), a catabolic pathway parallel to glycolysis and which participates in the generation of the reducing agent NADPH (the reduced form of nicotinamide adenine dinucleotide phosphate). Then, the HMP shunt was impaired by disrupting the related gene BmZwf1, which encodes glucose-6-phosphate dehydrogenase in this fungus. The resulting mutants on l-arabinose showed remarkably decreased conidiation, but a conversely increased mycelial dry weight compared with the wild-type. Our study demonstrates that l-arabinose acts to enhance resource allocation to asexual reproduction in B. maydis HITO7711 at the cost of vegetative growth, and suggests that this is mediated by the concomitant stimulation of the HMP shunt.
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Affiliation(s)
- Hiroshi Yoshida
- Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Chihiro Tanaka
- Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
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35
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Abstract
This introductory chapter describes the life cycle of Magnaporthe oryzae, the causal agent of rice blast disease. During plant infection, M. oryzae forms a specialized infection structure called an appressorium, which generates enormous turgor, applied as a mechanical force to breach the rice cuticle. Appressoria form in response to physical cues from the hydrophobic rice leaf cuticle and nutrient availability. The signaling pathways involved in perception of surface signals are described and the mechanism by which appressoria function is also introduced. Re-polarization of the appressorium requires a septin complex to organize a toroidal F-actin network at the base of the cell. Septin aggregation requires a turgor-dependent sensor kinase, Sln1, necessary for re-polarization of the appressorium and development of a rigid penetration hypha to rupture the leaf cuticle. Once inside the plant, the fungus undergoes secretion of a large set of effector proteins, many of which are directed into plant cells using a specific secretory pathway. Here they suppress plant immunity, but can also be perceived by rice immune receptors, triggering resistances. M. oryzae then manipulates pit field sites, containing plasmodesmata, to facilitate rapid spread from cell to cell in plant tissue, leading to disease symptom development.
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36
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Hong Y, Cai R, Guo J, Zhong Z, Bao J, Wang Z, Chen X, Zhou J, Lu GD. Carbon catabolite repressor MoCreA is required for the asexual development and pathogenicity of the rice blast fungus. Fungal Genet Biol 2020; 146:103496. [PMID: 33290821 DOI: 10.1016/j.fgb.2020.103496] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 11/12/2020] [Accepted: 11/27/2020] [Indexed: 11/16/2022]
Abstract
During the infection and colonization process, the rice blast fungus Magnaporthe oryzae faces various challenges from hostile environment, such as nutrient limitation and carbon stress, while carbon catabolite repression (CCR) mechanism would facilitate the fungus to shrewdly and efficiently utilize carbon nutrients under fickle nutritional conditions since it ensures the preferential utilization of most preferred carbon sources through repressing the expression of enzymes required for the utilization of less preferred carbon sources. Researches on M. oryzae CCR have made some progress, however the involved regulation mechanism is still largely obscured, especially, little is known about the key carbon catabolite repressor CreA. Here we identified and characterized the biological functions of the CreA homolog MoCreA in M. oryzae. MoCreA is constitutively expressed throughout all the life stages of the fungus, and it can shuttle between nucleus and cytoplasm which is induced by glucose. Following functional analyses of MoCreA suggested that it was required for the vegetative growth, conidiation, appressorium formation and pathogenicity of M. oryzae. Moreover, comparative transcriptomic analysis revealed that disruption of MoCreA resulted in the extensive gene expression variations, including a large number of carbon metabolism enzymes, transcription factors and pathogenicity-related genes. Taken together, our results demonstrated that, as a key regulator of CCR, MoCreA plays a vital role in precise regulation of the asexual development and pathogenicity of the rice blast fungus.
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Affiliation(s)
- Yonghe Hong
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Renli Cai
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jiayuan Guo
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhenhui Zhong
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jiandong Bao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Oceanography, Minjiang University, Fuzhou 350108, China; Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xiaofeng Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Oceanography, Minjiang University, Fuzhou 350108, China; Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Jie Zhou
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Guo-Dong Lu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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Zhu XM, Li L, Cai YY, Wu XY, Shi HB, Liang S, Qu YM, Naqvi NI, Del Poeta M, Dong B, Lin FC, Liu XH. A VASt-domain protein regulates autophagy, membrane tension, and sterol homeostasis in rice blast fungus. Autophagy 2020; 17:2939-2961. [PMID: 33176558 DOI: 10.1080/15548627.2020.1848129] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Sterols are a class of lipids critical for fundamental biological processes and membrane dynamics. These molecules are synthesized in the endoplasmic reticulum (ER) and are transported bi-directionally between the ER and plasma membrane (PM). However, the trafficking mechanism of sterols and their relationship with macroautophagy/autophagy are still poorly understood in the rice blast fungus Magnaporthe oryzae. Here, we identified the VAD1 Analog of StAR-related lipid transfer (VASt) domain-containing protein MoVast1 via co-immunoprecipitation in M. oryzae. Loss of MoVAST1 resulted in conidial defects, impaired appressorium development, and reduced pathogenicity. The MoTor (target of rapamycin in M. oryzae) activity is inhibited because MoVast1 deletion leads to high levels of sterol accumulation in the PM. Site-directed mutagenesis showed that the 902 T site is essential for localization and function of MoVast1. Through filipin or Flipper-TR staining, autophagic flux detection, MoAtg8 lipidation, and drug sensitivity assays, we uncovered that MoVast1 acts as a novel autophagy inhibition factor that monitors tension in the PM by regulating the sterol content, which in turn modulates the activity of MoTor. Lipidomics and transcriptomics analyses further confirmed that MoVast1 is an important regulator of lipid metabolism and the autophagy pathway. Our results revealed and characterized a novel sterol transfer protein important for M. oryzae pathogenicity.Abbreviations: AmB: amphotericin B; ATMT: Agrobacterium tumefaciens-mediated transformation; CM: complete medium; dpi: days post-inoculation; ER: endoplasmic reticulum; Flipper-TR: fluorescent lipid tension reporter; GO: Gene ontology; hpi: hours post-inoculation; IH: invasive hyphae; KEGG: kyoto encyclopedia of genes and genomes; MoTor: target of rapamycin in Magnaporthe oryzae; PalmC: palmitoylcarnitine; PM: plasma membrane; SD-N: synthetic defined medium without amino acids and ammonium sulfate; TOR: target of rapamycin; VASt: VAD1 Analog of StAR-related lipid transfer; YFP, yellow fluorescent protein.
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Affiliation(s)
- Xue-Ming Zhu
- St Ate Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China.,State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Lin Li
- St Ate Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Ying-Ying Cai
- St Ate Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Xi-Yu Wu
- St Ate Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Huan-Bin Shi
- St Ate Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Shuang Liang
- St Ate Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Ying-Min Qu
- St Ate Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Naweed I Naqvi
- Temasek Life Sciences Laboratory, Department of Biological Sciences, National University of Singapore, Singapore
| | - Maurizio Del Poeta
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA.,Division of Infectious Diseases, Stony Brook University, Stony Brook, New York, USA.,Veterans Affairs Medical Center, Northport, New York, USA
| | - Bo Dong
- Markey Cancer Center, University of Kentucky, College of Medicine, Lexington, KY, USA
| | - Fu-Cheng Lin
- St Ate Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China.,State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Xiao-Hong Liu
- St Ate Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
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38
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Rocha RO, Wilson RA. Magnaporthe oryzae nucleoside diphosphate kinase is required for metabolic homeostasis and redox-mediated host innate immunity suppression. Mol Microbiol 2020; 114:789-807. [PMID: 32936940 DOI: 10.1111/mmi.14580] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/25/2020] [Accepted: 07/19/2020] [Indexed: 12/25/2022]
Abstract
The fungus Magnaporthe oryzae causes blast, the most devastating disease of cultivated rice. After penetrating the leaf cuticle, M. oryzae grows as a biotroph in intimate contact with living rice epidermal cells before necrotic lesions develop. Biotrophic growth requires maintaining metabolic homeostasis while suppressing plant defenses, but the metabolic connections and requirements involved are largely unknown. Here, we characterized the M. oryzae nucleoside diphosphate kinase-encoding gene NDK1 and discovered it was essential for facilitating biotrophic growth by suppressing the host oxidative burst-the first line of plant defense. NDK enzymes reversibly transfer phosphate groups from tri- to diphosphate nucleosides. Correspondingly, intracellular nucleotide pools were perturbed in M. oryzae strains lacking NDK1 through targeted gene deletion, compared to WT. This affected metabolic homeostasis: TCA, purine and pyrimidine intermediates, and oxidized NADP+ , accumulated in Δndk1. cAMP and glutathione were depleted. ROS accumulated in Δndk1 hyphae. Functional appressoria developed on rice leaf sheath surfaces, but Δndk1 invasive hyphal growth was restricted and redox homeostasis was perturbed, resulting in unsuppressed host oxidative bursts that triggered immunity. We conclude Ndk1 modulates intracellular nucleotide pools to maintain redox balance via metabolic homeostasis, thus quenching the host oxidative burst and suppressing rice innate immunity during biotrophy.
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Affiliation(s)
- Raquel O Rocha
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Richard A Wilson
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
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39
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Rocha RO, Elowsky C, Pham NTT, Wilson RA. Spermine-mediated tight sealing of the Magnaporthe oryzae appressorial pore-rice leaf surface interface. Nat Microbiol 2020; 5:1472-1480. [PMID: 32929190 DOI: 10.1038/s41564-020-0786-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 08/04/2020] [Indexed: 12/13/2022]
Abstract
Cellular adhesion mediates many important plant-microbe interactions. In the devastating blast fungus Magnaporthe oryzae1, powerful glycoprotein-rich mucilage adhesives2 cement melanized and pressurized dome-shaped infection cells-appressoria-to host rice leaf surfaces. Enormous internal turgor pressure is directed onto a penetration peg emerging from the unmelanized, thin-walled pore at the appressorial base1-4, forcing it through the leaf cuticle where it elongates invasive hyphae in underlying epidermal cells5. Mucilage sealing around the appressorial pore facilitates turgor build-up2, but the molecular underpinnings of mucilage secretion and appressorial adhesion are unknown. Here, we discovered an unanticipated and sole role for spermine in facilitating mucilage production by mitigating endoplasmic reticulum (ER) stress in the developing appressorium. Mutant strains lacking the spermine synthase-encoding gene SPS1 progressed through all stages of appressorial development, including penetration peg formation, but cuticle penetration was unsuccessful due to reduced appressorial adhesion, which led to solute leakage. Mechanistically, spermine neutralized off-target oxygen free radicals produced by NADPH oxidase-1 (Nox1)3,6 that otherwise elicited ER stress and the unfolded protein response, thereby critically reducing mucilage secretion. Our study reveals that spermine metabolism via redox buffering of the ER underpins appressorial adhesion and rice cell invasion and provides insights into a process that is fundamental to host plant infection.
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Affiliation(s)
- Raquel O Rocha
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Christian Elowsky
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Ngoc T T Pham
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Richard A Wilson
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, USA.
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Crystal structures of Magnaporthe oryzae trehalose-6-phosphate synthase (MoTps1) suggest a model for catalytic process of Tps1. Biochem J 2020; 476:3227-3240. [PMID: 31455720 DOI: 10.1042/bcj20190289] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 08/22/2019] [Accepted: 08/27/2019] [Indexed: 11/17/2022]
Abstract
Trehalose-6-phosphate (T6P) synthase (Tps1) catalyzes the formation of T6P from UDP-glucose (UDPG) (or GDPG, etc.) and glucose-6-phosphate (G6P), and structural basis of this process has not been well studied. MoTps1 (Magnaporthe oryzae Tps1) plays a critical role in carbon and nitrogen metabolism, but its structural information is unknown. Here we present the crystal structures of MoTps1 apo, binary (with UDPG) and ternary (with UDPG/G6P or UDP/T6P) complexes. MoTps1 consists of two modified Rossmann-fold domains and a catalytic center in-between. Unlike Escherichia coli OtsA (EcOtsA, the Tps1 of E. coli), MoTps1 exists as a mixture of monomer, dimer, and oligomer in solution. Inter-chain salt bridges, which are not fully conserved in EcOtsA, play primary roles in MoTps1 oligomerization. Binding of UDPG by MoTps1 C-terminal domain modifies the substrate pocket of MoTps1. In the MoTps1 ternary complex structure, UDP and T6P, the products of UDPG and G6P, are detected, and substantial conformational rearrangements of N-terminal domain, including structural reshuffling (β3-β4 loop to α0 helix) and movement of a 'shift region' towards the catalytic centre, are observed. These conformational changes render MoTps1 to a 'closed' state compared with its 'open' state in apo or UDPG complex structures. By solving the EcOtsA apo structure, we confirmed that similar ligand binding induced conformational changes also exist in EcOtsA, although no structural reshuffling involved. Based on our research and previous studies, we present a model for the catalytic process of Tps1. Our research provides novel information on MoTps1, Tps1 family, and structure-based antifungal drug design.
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Tang C, Li T, Klosterman SJ, Tian C, Wang Y. The bZIP transcription factor VdAtf1 regulates virulence by mediating nitrogen metabolism in Verticillium dahliae. THE NEW PHYTOLOGIST 2020; 226:1461-1479. [PMID: 32040203 DOI: 10.1111/nph.16481] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 02/03/2020] [Indexed: 06/10/2023]
Abstract
The fungus Verticillium dahliae causes vascular wilt disease on hundreds of plant species. Homologs of the bZIP transcription factor Atf1 are required for virulence in most pathogenic fungi, but the molecular basis for their involvement is largely unknown. We performed targeted gene deletion, expression analysis, biochemistry and pathogenicity assays to demonstrate that VdAtf1 governs pathogenesis via the regulation of nitrosative resistance and nitrogen metabolism in V. dahliae. VdAtf1 controls pathogenesis via the regulation of nitric oxide (NO) resistance and inorganic nitrogen metabolism rather than oxidative resistance and is important for penetration peg formation in V. dahliae. VdAtf1 affects ammonium and nitrate assimilation in response to various nitrogen sources. VdAtf1 may be involved in regulating the expression of VdNut1. VdAtf1 responds to NO stress by strengthening the fungal cell wall, and by causing over-accumulation of methylglyoxal and glycerol, which in turn impacts NO detoxification. We also verified that the VdAtf1 ortholog in Fusarium graminearum mediates nitrogen metabolism, suggesting conservation of this function in related plant pathogenic fungi. Our findings revealed new functions of VdAtf1 in pathogenesis, response to nitrosative stress and nitrogen metabolism in V. dahliae. The results provide novel insights into the regulatory mechanisms of the transcription factor VdAtf1 in virulence.
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Affiliation(s)
- Chen Tang
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Tianyu Li
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Steven J Klosterman
- United States Department of Agriculture, Agricultural Research Service, Crop Improvement and Protection Research Unit, Salinas, CA, 93905, USA
| | - Chengming Tian
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Yonglin Wang
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, 100083, China
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Li G, Qi X, Sun G, Rocha RO, Segal LM, Downey KS, Wright JD, Wilson RA. Terminating rice innate immunity induction requires a network of antagonistic and redox-responsive E3 ubiquitin ligases targeting a fungal sirtuin. THE NEW PHYTOLOGIST 2020; 226:523-540. [PMID: 31828801 DOI: 10.1111/nph.16365] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 12/02/2019] [Indexed: 06/10/2023]
Abstract
Fungal phytopathogens can suppress plant immune mechanisms in order to colonize living host cells. Identifying all the molecular components involved is critical for elaborating a detailed systems-level model of plant infection probing pathogen weaknesses; yet, the hierarchy of molecular events controlling fungal responses to the plant cell is not clear. Here we show how, in the blast fungus Magnaporthe oryzae, terminating rice innate immunity requires a dynamic network of redox-responsive E3 ubiquitin ligases targeting fungal sirtuin 2 (Sir2), an antioxidation regulator required for suppressing the host oxidative burst. Immunoblotting, immunopurification, mass spectrometry and gene functional analyses showed that Sir2 levels responded to oxidative stress via a mechanism involving ubiquitination and three antagonistic E3 ubiquitin ligases: Grr1 and Ptr1 maintained basal Sir2 levels in the absence of oxidative stress; Upl3 facilitated Sir2 accumulation in response to oxidative stress. Grr1 and Upl3 interacted directly with Sir2 in a manner that decreased and scaled with oxidative stress, respectively. Deleting UPL3 depleted Sir2 during growth in rice cells, triggering host immunity and preventing infection. Overexpressing SIR2 in the Δupl3 mutant remediated pathogenicity. Our work reveals how redox-responsive E3 ubiquitin ligases in M. oryzae mediate Sir2 accumulation-dependent antioxidation to modulate plant innate immunity and host susceptibility.
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Affiliation(s)
- Gang Li
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Xiaobo Qi
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Guangchao Sun
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Raquel O Rocha
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Lauren M Segal
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Katherine S Downey
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Janet D Wright
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Richard A Wilson
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
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A Novel Site-Specific Integration System for Genetic Modification of Aspergillus flavus. G3-GENES GENOMES GENETICS 2020; 10:605-611. [PMID: 31818874 PMCID: PMC7003095 DOI: 10.1534/g3.119.400699] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Aspergillus flavus is a fungus that produces aflatoxin B1, one of the most carcinogenic secondary metabolites. Understanding the regulation mechanism of aflatoxin biosynthesis in this fungus requires precise methods for genomic integration of mutant alleles. To avoid the disadvantage of DNA integration into the genome by non-homologous or ectopic recombination, we developed a novel strategy for site-specific integration of foreign DNA by using a carboxin-resistant sdh2R allele (His 249 Leu). Our results demonstrated that the transformants were generated with a high efficiency (>96%) of correct integration into the sdh2-lcus of the genome of A. flavus NRRL 3357. The advantage of this method is that introduction of the eGFP expression cassette into the sdh2-locus had little effect on fungal growth and virulence while also being rapid and efficient. This system will be a valuable tool for genetic manipulation in A. flavus. To the best of our knowledge, this is the first report on the efficient site-specific integration at the sdh2-locus in the genome of Aspergillus.
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Abstract
The blast disease, caused by the ascomycete Magnaporthe oryzae, poses a great threat to rice production worldwide. Increasing use of fungicides and/or blast-resistant varieties of rice (Oryza sativa) has proved to be ineffective in long-term control of blast disease under field conditions. To develop effective and durable resistance to blast, it is important to understand the cellular mechanisms underlying pathogenic development in M. oryzae. In this review, we summarize the latest research in phototropism, autophagy, nutrient and redox signaling, and intrinsic phytohormone mimics in M. oryzae for cellular and metabolic adaptation(s) during its interactions with the host plants.
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Affiliation(s)
- Yi Zhen Deng
- Integrative Microbiology Research Centre and State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China;
| | - Naweed I Naqvi
- Temasek Life Sciences Laboratory and the Department of Biological Sciences, National University of Singapore, Singapore 117604;
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Metabolomics Analysis Identifies Sphingolipids as Key Signaling Moieties in Appressorium Morphogenesis and Function in Magnaporthe oryzae. mBio 2019; 10:mBio.01467-19. [PMID: 31431550 PMCID: PMC6703424 DOI: 10.1128/mbio.01467-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The blast fungus initiates infection using a heavily melanized, dome-shaped infection structure known as the appressorium, which forcibly ruptures the cuticle to enter the rice leaf tissue. How this process takes place remains not fully understood. Here, we used untargeted metabolomics analyses to profile the metabolome of developing appressoria and identified significant changes in six key metabolic pathways, including early sphingolipid biosynthesis. Analyses employing small molecule inhibitors, gene disruption, or genetic and chemical complementation demonstrated that ceramide compounds of the sphingolipid biosynthesis pathway are essential for normal appressorial development controlled by mitosis. In addition, ceramide was found to act upstream from the protein kinase C-mediated cell wall integrity pathway during appressorium repolarization and pathogenicity in rice blast. Further discovery of the sphingolipid biosynthesis pathway revealed that glucosylceramide (GlcCer) synthesized by ceramide is the key substance affecting the pathogenicity of Magnaporthe oryzae Our results provide new insights into the chemical moieties involved in the infection-related signaling networks, thereby revealing a potential target for the development of novel control agents against the major disease of rice and other cereals.IMPORTANCE Our untargeted analysis of metabolomics throughout the course of pathogenic development gave us an unprecedented high-resolution view of major shifts in metabolism that occur in the topmost fungal pathogen that infects rice, wheat, barley, and millet. Guided by these metabolic insights, we demonstrated their practical application by using two different small-molecule inhibitors of sphingolipid biosynthesis enzymes to successfully block the pathogenicity of M. oryzae Our study thus defines the sphingolipid biosynthesis pathway as a key step and potential target that can be exploited for the development of antifungal agents. Furthermore, future investigations that exploit such important metabolic intermediates will further deepen our basic understanding of the molecular mechanisms underlying the establishment of fungal blast disease in important cereal crops.
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Sun G, Qi X, Wilson RA. A Feed-Forward Subnetwork Emerging from Integrated TOR- and cAMP/PKA-Signaling Architecture Reinforces Magnaporthe oryzae Appressorium Morphogenesis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:593-607. [PMID: 30431400 DOI: 10.1094/mpmi-10-18-0287-r] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Appressoria are important mediators of plant-microbe interactions. In the devastating rice blast pathogen Magnaporthe oryzae, appressorial morphogenesis from germ tube tips requires activated cAMP/PKA signaling and inactivated TOR signaling (TORoff). TORoff temporarily arrests G2 at a metabolic checkpoint during the single round of mitosis that occurs following germination. G2 arrest induces autophagy and appressorium formation concomitantly, allowing reprogression of the cell cycle to G1/G0 quiescence and a single appressorial nucleus. Inappropriate TOR activation abrogates G2 arrest and inhibits cAMP/PKA signaling downstream of cPKA. This results in multiple rounds of germ tube mitosis and the loss of autophagy and appressoria formation. How cAMP/PKA signaling connects to cell cycle progression and autophagy is not known. To address this, we interrogated TOR and cAMP/PKA pathways using signaling mutants, different surface properties, and specific cell cycle inhibitors and discovered a feed-forward subnetwork arising from TOR- and cAMP/PKA-signaling integration. This adenylate cyclase-cAMP-TOR-adenylate cyclase subnetwork reinforces cAMP/PKA-dependent appressorium formation under favorable environmental conditions. Under unfavorable conditions, the subnetwork collapses, resulting in reversible cell cycle-mediated germ tube growth regardless of external nutrient status. Collectively, this work provides new molecular insights on germ tube morphogenetic decision-making in response to static and dynamic environmental conditions.
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Affiliation(s)
- Guangchao Sun
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, U.S.A
| | - Xiaobo Qi
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, U.S.A
| | - Richard A Wilson
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, U.S.A
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Sun G, Elowsky C, Li G, Wilson RA. TOR-autophagy branch signaling via Imp1 dictates plant-microbe biotrophic interface longevity. PLoS Genet 2018; 14:e1007814. [PMID: 30462633 PMCID: PMC6281275 DOI: 10.1371/journal.pgen.1007814] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 12/05/2018] [Accepted: 11/06/2018] [Indexed: 01/07/2023] Open
Abstract
Like other intracellular eukaryotic phytopathogens, the devastating rice blast fungus Magnaporthe (Pyricularia) oryzae first infects living host cells by elaborating invasive hyphae (IH) surrounded by a plant-derived membrane. This forms an extended biotrophic interface enclosing an apoplastic compartment into which fungal effectors can be deployed to evade host detection. M. oryzae also forms a focal, plant membrane-rich structure, the biotrophic interfacial complex (BIC), that accumulates cytoplasmic effectors for translocation into host cells. Molecular decision-making processes integrating fungal growth and metabolism in host cells with interface function and dynamics are unknown. Here, we report unanticipated roles for the M. oryzae Target-of-Rapamycin (TOR) nutrient-signaling pathway in mediating plant-fungal biotrophic interface membrane integrity. Through a forward genetics screen for M. oryzae mutant strains resistant to the specific TOR kinase inhibitor rapamycin, we discovered IMP1 encoding a novel vacuolar protein required for membrane trafficking, V-ATPase assembly, organelle acidification and autophagy induction. During infection, Δimp1 deletants developed intracellular IH in the first infected rice cell following cuticle penetration. However, fluorescently labeled effector probes revealed that interface membrane integrity became compromised as biotrophy progressed, abolishing the BIC and releasing apoplastic effectors into host cytoplasm. Growth between rice cells was restricted. TOR-independent autophagy activation in Δimp1 deletants (following infection) remediated interface function and cell-to-cell growth. Autophagy inhibition in wild type (following infection) recapitulated Δimp1. In addition to vacuoles, Imp1GFP localized to IH membranes in an autophagy-dependent manner. Collectively, our results suggest TOR-Imp1-autophagy branch signaling mediates membrane homeostasis to prevent catastrophic erosion of the biotrophic interface, thus facilitating fungal growth in living rice cells. The significance of this work lays in elaborating a novel molecular mechanism of infection stressing the dominance of fungal metabolism and metabolic control in sustaining long-term plant-microbe interactions. This work also has implications for understanding the enigmatic biotrophy to necrotrophy transition. Plant-associated fungi can form intimate connections with living host cells. Clarifying the molecular drivers of these interactions, and which partner is dominant, might be important in understanding how beneficial plant-fungal relationships can be enhanced to improve crop yields while pathogenic interactions that threaten crop health are disrupted. In common with other symbionts and phytopathogens, the devastating rice blast fungus Magnaporthe oryzae elaborates invasive hyphae in living host cells surrounded by plant-derived membranes. Nothing is known at the molecular signaling level about how such plant-microbe biotrophic interfacial zones are maintained as the fungus grows in and between host cells. Here, we report that fungal membrane trafficking processes controlled by nutrient signaling pathways are critical for maintaining biotrophic interface integrity during M. oryzae growth in rice cells. Impairing these processes resulted in erosion of the plant-microbe interface and failure of the fungus to thrive. To our knowledge, this work presents the first evidence indicating that the fungal partner is dominant in propagating the plant-microbe boundary. This suggests that the biotrophic interface is a fungal construct and provides clues on how such interfaces might be modulated to benefit the host plant.
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Affiliation(s)
- Guangchao Sun
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Christian Elowsky
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Gang Li
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Richard A. Wilson
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
- * E-mail:
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Conidial Morphogenesis and Septin-Mediated Plant Infection Require Smo1, a Ras GTPase-Activating Protein in Magnaporthe oryzae. Genetics 2018; 211:151-167. [PMID: 30446520 PMCID: PMC6325701 DOI: 10.1534/genetics.118.301490] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/12/2018] [Indexed: 01/21/2023] Open
Abstract
The pathogenic life cycle of the rice blast fungus Magnaporthe oryzae involves a series of morphogenetic changes, essential for its ability to cause disease. The smo mutation was identified > 25 years ago, and affects the shape and development of diverse cell types in M. oryzae, including conidia, appressoria, and asci. All attempts to clone the SMO1 gene by map-based cloning or complementation have failed over many years. Here, we report the identification of SMO1 by a combination of bulk segregant analysis and comparative genome analysis. SMO1 encodes a GTPase-activating protein, which regulates Ras signaling during infection-related development. Targeted deletion of SMO1 results in abnormal, nonadherent conidia, impaired in their production of spore tip mucilage. Smo1 mutants also develop smaller appressoria, with a severely reduced capacity to infect rice plants. SMO1 is necessary for the organization of microtubules and for septin-dependent remodeling of the F-actin cytoskeleton at the appressorium pore. Smo1 physically interacts with components of the Ras2 signaling complex, and a range of other signaling and cytoskeletal components, including the four core septins. SMO1 is therefore necessary for the regulation of RAS activation required for conidial morphogenesis and septin-mediated plant infection.
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Marroquin-Guzman M, Krotz J, Appeah H, Wilson RA. Metabolic constraints on Magnaporthe biotrophy: loss of de novo asparagine biosynthesis aborts invasive hyphal growth in the first infected rice cell. MICROBIOLOGY (READING, ENGLAND) 2018; 164:1541-1546. [PMID: 30351267 DOI: 10.1099/mic.0.000713] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
The blast fungus Magnaporthe oryzae devastates global rice yields and is an emerging threat to wheat. Determining the metabolic strategies underlying M. oryzae growth in host cells could lead to the development of new plant protection approaches against blast. Here, we targeted asparagine synthetase (encoded by ASN1), which is required for the terminal step in asparagine production from aspartate and glutamine, the sole pathway to de novo asparagine biosynthesis in M. oryzae. Consequently, the Δasn1 mutant strains could not grow on minimal media without asparagine supplementation. Spores harvested from supplemented plates could form appressoria and penetrate rice leaf surfaces, but biotrophic growth was aborted and the Δasn1 strains were nonpathogenic. This work provides strong genetic evidence that de novo asparagine biosynthesis, and not acquisition from the host, is a critical and potentially exploitable metabolic strategy employed by M. oryzae in order to successfully colonize rice cells.
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Affiliation(s)
| | - Juliana Krotz
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Harriet Appeah
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Richard A Wilson
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
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Leaf Eh and pH: A Novel Indicator of Plant Stress. Spatial, Temporal and Genotypic Variability in Rice (Oryza sativa L.). AGRONOMY-BASEL 2018. [DOI: 10.3390/agronomy8100209] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A wealth of knowledge has been published in the last decade on redox regulations in plants. However, these works remained largely at cellular and organelle levels. Simple indicators of oxidative stress at the plant level are still missing. We developed a method for direct measurement of leaf Eh and pH, which revealed spatial, temporal, and genotypic variations in rice. Eh (redox potential) and Eh@pH7 (redox potential corrected to pH 7) of the last fully expanded leaf decreased after sunrise. Leaf Eh was high in the youngest leaf and in the oldest leaves, and minimum for the last fully expanded leaf. Leaf pH decreased from youngest to oldest leaves. The same gradients in Eh-pH were measured for various varieties, hydric conditions, and cropping seasons. Rice varieties differed in Eh, pH, and/or Eh@pH7. Leaf Eh increases and leaf pH decreases with plant age. These patterns and dynamics in leaf Eh-pH are in accordance with the pattern and dynamics of disease infections. Leaf Eh-pH can bring new insight on redox processes at plant level and is proposed as a novel indicator of plant stress/health. It could be used by agronomists, breeders, and pathologists to accelerate the development of crop cultivation methods leading to agroecological crop protection.
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