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Liu Z, Zhu Z, Huang Y, Nong S, Jiang M, Yi S, Xie D, Hu H. Identification of gene modules and hub genes associated with Colletotrichum siamense infection in mango using weighted gene co-expression network analysis. BMC Genomics 2023; 24:710. [PMID: 37996781 PMCID: PMC10668491 DOI: 10.1186/s12864-023-09811-6] [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: 07/01/2023] [Accepted: 11/17/2023] [Indexed: 11/25/2023] Open
Abstract
Colletotrichum siamense is a hemibiotrophic ascomycetous fungus responsible for mango anthracnose. The key genes involved in C. siamense infection remained largely unknown. In this study, we conducted weighted gene co-expression network analysis (WGCNA) of RNA-seq data to mine key genes involved in Colletotrichum siamense-mango interactions. Gene modules of Turquoise and Salmon, containing 1039 and 139 respectively, were associated with C. siamense infection, which were conducted for further analysis. GO enrichment analysis revealed that protein synthesis, organonitrogen compound biosynthetic and metabolic process, and endoplasmic reticulum-related genes were associated with C. siamense infection. A total of 568 proteins had homologs in the PHI database, 370 of which were related to virulence. The hub genes in each module were identified, which were annotated as O-methyltransferase (Salmon) and Clock-controlled protein 6 (Turquoise). A total of 24 proteins exhibited characteristics of SCRPs. By using transient expression in Nicotiana benthamiana, the SCRPs of XM_036637681.1 could inhibit programmed cell death (PCD) that induced by BAX (BCL-2-associated X protein), suggesting that it may play important roles in C. siamense infection. A mango-C. siamense co-expression network was constructed, and the mango gene of XM_044632979.1 (auxin-induced protein 15A-like) was positively associated with 5 SCRPs. These findings help to deepen the current understanding of necrotrophic stage in C. siamense infection.
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Affiliation(s)
- Zongling Liu
- School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, 533000, China.
- Guangxi Key Laboratory of Biology for Mango, Baise, 533000, China.
| | - Zhengjie Zhu
- Guangxi Key Laboratory of Biology for Mango, Baise, 533000, China
| | - Yuanhe Huang
- School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, 533000, China
| | - Song Nong
- School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, 533000, China
| | - Minli Jiang
- School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, 533000, China
| | - Sangui Yi
- School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, 533000, China
| | - Delong Xie
- School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, 533000, China
| | - Hongliu Hu
- School of Basic Medical Sciences, Youjiang Medical University for Nationalities, Baise, 533000, China
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Dofuor AK, Quartey NKA, Osabutey AF, Antwi-Agyakwa AK, Asante K, Boateng BO, Ablormeti FK, Lutuf H, Osei-Owusu J, Osei JHN, Ekloh W, Loh SK, Honger JO, Aidoo OF, Ninsin KD. Mango anthracnose disease: the current situation and direction for future research. Front Microbiol 2023; 14:1168203. [PMID: 37692388 PMCID: PMC10484599 DOI: 10.3389/fmicb.2023.1168203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 08/03/2023] [Indexed: 09/12/2023] Open
Abstract
Mango anthracnose disease (MAD) is a destructive disease of mangoes, with estimated yield losses of up to 100% in unmanaged plantations. Several strains that constitute Colletotrichum complexes are implicated in MAD worldwide. All mangoes grown for commercial purposes are susceptible, and a resistant cultivar for all strains is not presently available on the market. The infection can widely spread before being detected since the disease is invincible until after a protracted latent period. The detection of multiple strains of the pathogen in Mexico, Brazil, and China has prompted a significant increase in research on the disease. Synthetic pesticide application is the primary management technique used to manage the disease. However, newly observed declines in anthracnose susceptibility to many fungicides highlight the need for more environmentally friendly approaches. Recent progress in understanding the host range, molecular and phenotypic characterization, and susceptibility of the disease in several mango cultivars is discussed in this review. It provides updates on the mode of transmission, infection biology and contemporary management strategies. We suggest an integrated and ecologically sound approach to managing MAD.
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Affiliation(s)
- Aboagye Kwarteng Dofuor
- Department of Biological Sciences, School of Natural and Environmental Sciences, University of Environment and Sustainable Development, Somanya, Ghana
| | - Naa Kwarley-Aba Quartey
- Department of Food Science and Technology, Faculty of Biosciences, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | | | - Kwasi Asante
- Coconut Research Program, Oil Palm Research Institute, Council for Scientific and Industrial Research, Sekondi-Takoradi, Ghana
| | - Belinda Obenewa Boateng
- Coconut Research Program, Oil Palm Research Institute, Council for Scientific and Industrial Research, Sekondi-Takoradi, Ghana
| | - Fred Kormla Ablormeti
- Coconut Research Program, Oil Palm Research Institute, Council for Scientific and Industrial Research, Sekondi-Takoradi, Ghana
| | - Hanif Lutuf
- Crop Protection Division, Oil Palm Research Institute, Council for Scientific and Industrial Research, Kade, Ghana
| | - Jonathan Osei-Owusu
- Department of Physical and Mathematical Sciences, School of Natural and Environmental Sciences, University of Environment and Sustainable Development, Somanya, Ghana
| | - Joseph Harold Nyarko Osei
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - William Ekloh
- Department of Biochemistry, School of Biological Sciences, College of Agriculture and Natural Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Seyram Kofi Loh
- Department of Built Environment, School of Sustainable Development, University of Environment and Sustainable Development, Somanya, Ghana
| | - Joseph Okani Honger
- Soil and Irrigation Research Centre, College of Basic and Applied Sciences, School of Agriculture, University of Ghana, Accra, Ghana
| | - Owusu Fordjour Aidoo
- Department of Biological Sciences, School of Natural and Environmental Sciences, University of Environment and Sustainable Development, Somanya, Ghana
| | - Kodwo Dadzie Ninsin
- Department of Biological Sciences, School of Natural and Environmental Sciences, University of Environment and Sustainable Development, Somanya, Ghana
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Deb L, Dutta P, Mandal MK, Singh SB. Antimicrobial Traits of Beauveria bassiana Against Rhizoctonia solani, the Causal Agent of Sheath Blight of Rice Under Field Conditions. PLANT DISEASE 2023:PDIS04220806RE. [PMID: 37327392 DOI: 10.1094/pdis-04-22-0806-re] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Beauveria bassiana, an entomopathogenic fungus, has recently drawn attention worldwide not only as a potential biocontrol agent against insect pests but also for its other beneficial roles as plant disease antagonist, endophyte, plant growth promoter, and beneficial rhizosphere colonizer. In the present study, 53 native isolates of B. bassiana were screened for antifungal ability against Rhizoctonia solani, the causal agent of sheath blight of rice. Also, the mechanisms underlying such interaction and the responsible antimicrobial traits involved were studied. Following this, potential B. bassiana isolates were assayed against the reduction of sheath blight of rice under field conditions. The results showed that B. bassiana exhibited antagonistic behavior against R. solani with a percent mycelial inhibition recorded maximum of up to 71.15%. Mechanisms behind antagonism were the production of cell-wall-degrading enzymes, mycoparasitism, and the release of secondary metabolites. The study also deciphered several antimicrobial traits and the presence of virulent genes in B. bassiana as a determinant of potential plant disease antagonists. Under field conditions, combined application of the B. bassiana microbial consortium as a seed treatment, seedling root dip, and foliar sprays showed reduced sheath blight disease incidence and severity up to 69.26 and 60.50%, respectively, along with enhanced plant-growth-promoting attributes. This is one of the few studies investigating the antagonistic abilities of the entomopathogenic fungus B. bassiana against phytopathogen R. solani and the underlying mechanisms involved.
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Affiliation(s)
- Lipa Deb
- School of Crop Protection, College of Post-Graduate Studies in Agricultural Sciences, Central Agricultural University (Imphal), Umiam, Meghalaya 793103, India
| | - Pranab Dutta
- School of Crop Protection, College of Post-Graduate Studies in Agricultural Sciences, Central Agricultural University (Imphal), Umiam, Meghalaya 793103, India
| | - Mihir Kumar Mandal
- Department of Plant Pathology, University of California-Davis, Salinas, CA 93905, U.S.A
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Wang C, Huang Z, Duan Z, Zhu L, Di R, Bao Y, Powell CA, Hu Q, Chen B, Zhang M, Yao W. Pectate Lyase from Fusarium sacchari Induces Plant Immune Responses and Contributes to Virulence. Microbiol Spectr 2023; 11:e0016523. [PMID: 37140457 PMCID: PMC10269888 DOI: 10.1128/spectrum.00165-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 04/13/2023] [Indexed: 05/05/2023] Open
Abstract
Fusarium sacchari is one of the primary pathogens causing Pokkah Boeng disease (PBD) in sugarcane in China. Pectate lyases (PL), which play a critical role in pectin degradation and fungal virulence, have been extensively studied in major bacterial and fungal pathogens of a wide range of plant species. However, only a few PLs have been functionally investigated. In this study, we analyzed the function of the pectate lyase gene, FsPL, from F. sacchari. FsPL is a key virulence factor of F. sacchari and can induce plant cell death. FsPL also triggers the pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) response in Nicotiana benthamiana, as reflected by increases in reactive oxygen species (ROS) production, electrolyte leakage, and callose accumulation, as well as the upregulation of defense response genes. In addition, our study also found that the signal peptide of FsPL was necessary for induced cell death and PTI responses. Virus-induced gene silencing showed that FsPL-induced cell death in Nicotiana benthamiana was mediated by leucine-rich repeat (LRR) receptor-like kinases BAK1 and SOBIR1. Thus, FsPL may not only be a critical virulence factor for F. sacchari but may also induce plant defense responses. These findings provide new insights into the functions of pectate lyase in host-pathogen interactions. IMPORTANCE Pokkah Boeng disease (PBD) is one of the main diseases affecting sugarcane in China, seriously damaging sugarcane production and economic development. Therefore, it is important to clarify the pathogenic mechanisms of this disease and to provide a theoretical basis for the breeding of PBD-resistant sugarcane strains. The present study aimed to analyze the function of FsPL, a recently identified pectate lyase gene from F. sacchari. FsPL is a key virulence factor of F. sacchari that induces plant cell death. Our results provide new insights into the function of pectate lyase in host-pathogen interactions.
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Affiliation(s)
- Caixia Wang
- State Key Lab for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi Key Lab of Sugarcane Biology, Guangxi University, Nanning, China
| | - Zhen Huang
- State Key Lab for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi Key Lab of Sugarcane Biology, Guangxi University, Nanning, China
| | - Zhenzhen Duan
- State Key Lab for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi Key Lab of Sugarcane Biology, Guangxi University, Nanning, China
| | - Lixiang Zhu
- State Key Lab for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi Key Lab of Sugarcane Biology, Guangxi University, Nanning, China
| | - Ruolin Di
- State Key Lab for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi Key Lab of Sugarcane Biology, Guangxi University, Nanning, China
| | - Yixue Bao
- State Key Lab for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi Key Lab of Sugarcane Biology, Guangxi University, Nanning, China
| | | | - Qin Hu
- State Key Lab for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi Key Lab of Sugarcane Biology, Guangxi University, Nanning, China
| | - Baoshan Chen
- State Key Lab for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi Key Lab of Sugarcane Biology, Guangxi University, Nanning, China
| | - Muqing Zhang
- State Key Lab for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi Key Lab of Sugarcane Biology, Guangxi University, Nanning, China
- IRREC-IFAS, University of Florida, Fort Pierce, Florida, USA
| | - Wei Yao
- State Key Lab for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi Key Lab of Sugarcane Biology, Guangxi University, Nanning, China
- IRREC-IFAS, University of Florida, Fort Pierce, Florida, USA
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Yang Z, Chen Y, Wang Y, Xia H, Zheng S, Xie S, Cao Y, Liu J, Sehar S, Lin Y, Guo Y, Shamsi IH. Nitrogen metabolic rate and differential ammonia volatilization regulate resistance against opportunistic fungus Alternaria alternata in tobacco. FRONTIERS IN PLANT SCIENCE 2022; 13:1003534. [PMID: 36212279 PMCID: PMC9538177 DOI: 10.3389/fpls.2022.1003534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 08/22/2022] [Indexed: 06/16/2023]
Abstract
Nutritional correlations between plants and pathogens can crucially affect disease severity. As an essential macronutrient, the availability of nitrogen (N) and the types of N content play a fundamental part not only in energy metabolism and protein synthesis but also in pathogenesis. However, a direct connection has not yet been established between differences in the level of resistance and N metabolism. Pertinently, former studies hold ammonia (NH3) accountable for the development of diseases in tobacco (Nicotiana tabacum L.) and in some post-harvest fruits. With a purpose of pinpointing the function of NH3 volatilization on Alternaria alternata (Fries) Keissl pathogenesis and its correlation with both N metabolism and resistance differences to Alternaria alternata infection in tobacco, leaf tissue of two tobacco cultivars with susceptibility (Changbohuang; CBH), or resistance (Jingyehuang; JYH) were analyzed apropos of ammonia compensation point, apoplastic NH4 + concentration, pH value as well as activities of key enzymes and N status. At the leaf age of 40 to 60 d, the susceptible cultivar had a significantly higher foliar apoplastic ammonium (NH4 +) concentration, pH value and NH3 volatilization potential compared to the resistant one accompanied by a significant reduction in glutamine synthetase (GS), which in particular was a primary factor causing the NH3 volatilization. The NH4 + concentration in CBH was 1.44 times higher than that in JYH, and CBH had NH3 compensation points that were 7.09, 6.15 and 4.35-fold higher than those of JYH at 40, 50 and 60 d, respectively. Moreover, the glutamate dehydrogenase (GDH) activity had an upward tendency related to an increased NH4 + accumulation in both leaf tissues and apoplast but not with the NH3 compensation point. Collectively, our results strongly suggest that the accumulation of NH3 volatilization, rather than NH4 + and total N, was the primary factor inducing the Alternaria alternata infection in tobacco. Meanwhile, the susceptible cultivar was characterized by a higher N re-transfer ability of NH3 volatilization, in contrast to the disease-resistant cultivar, and had a stronger capability of N assimilation and reutilization. This study provides a deeper understanding of the pathogenicity mechanism induced by Alternaria alternata, which is useful for breeding Alternaria alternata-resistant varieties of tobacco, at the same time, our research is also conducive to control tobacco brown spot caused by Alternaria alternata in the field.
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Affiliation(s)
- Zhixiao Yang
- Guizhou Academy of Tobacco Science, Guiyang, Guizhou, China
| | - Yi Chen
- Guizhou Academy of Tobacco Science, Guiyang, Guizhou, China
| | - Yi Wang
- Guizhou Academy of Tobacco Science, Guiyang, Guizhou, China
| | - Haiqian Xia
- Guizhou Academy of Tobacco Science, Guiyang, Guizhou, China
| | - Shaoqing Zheng
- Guizhou Academy of Tobacco Science, Guiyang, Guizhou, China
| | - Shengdong Xie
- Guizhou Academy of Tobacco Science, Guiyang, Guizhou, China
| | - Yi Cao
- Guizhou Academy of Tobacco Science, Guiyang, Guizhou, China
| | - Jiemin Liu
- Guizhou Provincial People’s Hospital, Guiyang, Guizhou, China
| | - Shafaque Sehar
- Zhejiang Key Laboratory of Crop Germplasm Resource, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Yingchao Lin
- Guizhou Academy of Tobacco Science, Guiyang, Guizhou, China
| | - Yushuang Guo
- Guizhou Academy of Tobacco Science, Guiyang, Guizhou, China
| | - Imran Haider Shamsi
- Zhejiang Key Laboratory of Crop Germplasm Resource, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
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Abstract
Most genomes within the species complex of Fusarium oxysporum are organized into two compartments: the core chromosomes (CCs) and accessory chromosomes (ACs). As opposed to CCs, which are conserved and vertically transmitted to carry out essential housekeeping functions, lineage- or strain-specific ACs are believed to be initially horizontally acquired through unclear mechanisms. These two genomic compartments are different in terms of gene density, the distribution of transposable elements, and epigenetic markers. Although common in eukaryotes, the functional importance of ACs is uniquely emphasized among fungal species, specifically in relationship to fungal pathogenicity and their adaptation to diverse hosts. With a focus on the cross-kingdom fungal pathogen F. oxysporum, this review provides a summary of the differences between CCs and ACs based on current knowledge of gene functions, genome structures, and epigenetic signatures, and explores the transcriptional crosstalk between the core and accessory genomes.
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Kang X, Csetenyi L, Gadd GM. Monazite transformation into Ce‐ and La‐containing oxalates by
Aspergillus niger. Environ Microbiol 2020; 22:1635-1648. [DOI: 10.1111/1462-2920.14964] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/19/2020] [Accepted: 02/26/2020] [Indexed: 11/29/2022]
Affiliation(s)
- Xia Kang
- Geomicrobiology Group, School of Life SciencesUniversity of Dundee Dundee DD1 5EH Scotland, UK
| | - Laszlo Csetenyi
- Concrete Technology Group, Department of Civil EngineeringUniversity of Dundee Dundee DD1 4HN Scotland, UK
| | - Geoffrey Michael Gadd
- Geomicrobiology Group, School of Life SciencesUniversity of Dundee Dundee DD1 5EH Scotland, UK
- State Key Laboratory of Heavy Oil Processing, Beijing Key Laboratory of Oil and Gas Pollution ControlCollege of Chemical Engineering and Environment, China University of Petroleum 18 Fuxue Road, Changping District, Beijing 102249 China
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Impact Injury at Harvest Promotes Body Rots in ‘Hass’ Avocado Fruit upon Ripening. HORTICULTURAE 2020. [DOI: 10.3390/horticulturae6010011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Global demand for avocados has risen rapidly in recent years, yet supplying fruit that consistently meets consumer expectations for quality remains a challenge in the industry. Body rots in avocado fruit are a leading cause of consumer dissatisfaction. Anecdotal evidence suggests that body rot development may be promoted by mechanical injury at harvest and packing, despite the fruit being hard, green and mature (i.e., unripe) at these stages. Here, ‘Hass’ avocado fruit, harvested across multiple fruiting seasons from commercial orchards, were subjected to controlled impact from drop heights of 15–60 cm at the time of harvest or packing. With increasing drop height, body rot development at eating ripe stage generally occurred more frequently and produced larger lesions at the impact site and, in some experiments, elsewhere on the fruit. These findings refute a general belief that green mature avocado fruit can tolerate a degree of rough physical handling without ripe fruit quality being compromised. Ideally, best avocado harvesting and packing practice should recognize that unripe fruit must not experience drop heights of 30 cm or higher.
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Hu Y, Lian L, Xia J, Hu S, Xu W, Zhu J, Ren A, Shi L, Zhao MW. Influence of PacC on the environmental stress adaptability and cell wall components of Ganoderma lucidum. Microbiol Res 2019; 230:126348. [PMID: 31639624 DOI: 10.1016/j.micres.2019.126348] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/01/2019] [Accepted: 09/28/2019] [Indexed: 10/25/2022]
Abstract
The transcription factor PacC/Rim101 participates in environmental pH adaptation, development and secondary metabolism in many fungi, but whether PacC/Rim101 contributes to fungal adaptation to environmental stress remains unclear. In our previous study, a homologous gene of PacC/Rim101 was identified, and PacC-silenced strains of the agaricomycete Ganoderma lucidum were constructed. In this study, we further investigated the functions of PacC in G. lucidum and found that PacC-silenced strains were hypersensitive to environmental stresses, such as osmotic stress, oxidative stress and cell wall stress, compared with wild-type (WT) and empty-vector control (CK) strains. In addition, transmission electron microscopy images of the cell wall structure showed that the cell walls of the PacC-silenced strains were thinner (by approximately 25-30%) than those of the WT and CK strains. Further analysis of cell wall composition showed that the β-1,3-glucan content in the PacC-silenced strains was only approximately 78-80% of that in the WT strain, and the changes in β-1,3-glucan content were consistent with downregulation of glucan synthase gene expression. The ability of PacC to bind to the promoters of glucan synthase-encoding genes confirms that PacC transcriptionally regulates these genes.
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Affiliation(s)
- Yanru Hu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Jiangsu, Nanjing 210095, People's Republic of China
| | - Lingdan Lian
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Jiangsu, Nanjing 210095, People's Republic of China
| | - Jiale Xia
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Jiangsu, Nanjing 210095, People's Republic of China
| | - Shishan Hu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Jiangsu, Nanjing 210095, People's Republic of China
| | - Wenzhao Xu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Jiangsu, Nanjing 210095, People's Republic of China
| | - Jing Zhu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Jiangsu, Nanjing 210095, People's Republic of China
| | - Ang Ren
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Jiangsu, Nanjing 210095, People's Republic of China
| | - Liang Shi
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Jiangsu, Nanjing 210095, People's Republic of China
| | - Ming Wen Zhao
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life Sciences, Nanjing Agricultural University, Jiangsu, Nanjing 210095, People's Republic of China.
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Wu Y, Yin Z, Xu L, Feng H, Huang L. VmPacC Is Required for Acidification and Virulence in Valsa mali. Front Microbiol 2018; 9:1981. [PMID: 30190714 PMCID: PMC6115506 DOI: 10.3389/fmicb.2018.01981] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 08/06/2018] [Indexed: 11/18/2022] Open
Abstract
The role of the transcription factor PacC has been characterised in several pathogenic fungi, and it affects virulence via several mechanisms. In this study, we examined the role of the PacC homolog VmPacC in Valsa mali, the causal agent of apple canker disease. We found that the expression of VmPacC was up-regulated in neutral and alkaline pH and during infection. At pH 6–10, the radial growth of a VmPacC deletion mutant decreased compared to wild-type. In addition, the sensitivity to oxidative stress of the VmPacC deletion mutant was impaired, as its growth was more severely inhibited by H2O2 than that of the wild-type. The lesion size caused by the VmPacC deletion mutant was smaller than that of the wild-type on apple leaves and twigs. Interestingly, expression of pectinase genes increased in deletion mutant during infection. To further confirm the negative regulation, we generated dominant activated C-27 allele mutants that constitutively express VmPacC. The pectinase activity of activated mutants was reduced at pH 4. We further observed that V. mali can acidify the pH during infection, and that the capacity for acidification was impaired after VmPacC deletion. Furthermore, VmPacC is involved in the generation of citric acid, which affects virulence. These results indicate that VmPacC is part of the fungal responses to neutral and alkaline pH and oxidative stress. More importantly, VmPacC is required for acidification of its environment and for full virulence in V. mali.
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Affiliation(s)
- Yuxing Wu
- State Key Laboratory of Crop Stress Biology for Arid Areas, China-Australia Joint Research Centre for Abiotic and Biotic Stress Management, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Zhiyuan Yin
- State Key Laboratory of Crop Stress Biology for Arid Areas, China-Australia Joint Research Centre for Abiotic and Biotic Stress Management, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Liangsheng Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas, China-Australia Joint Research Centre for Abiotic and Biotic Stress Management, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Hao Feng
- State Key Laboratory of Crop Stress Biology for Arid Areas, China-Australia Joint Research Centre for Abiotic and Biotic Stress Management, College of Plant Protection, Northwest A&F University, Yangling, China
| | - Lili Huang
- State Key Laboratory of Crop Stress Biology for Arid Areas, China-Australia Joint Research Centre for Abiotic and Biotic Stress Management, College of Plant Protection, Northwest A&F University, Yangling, China
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11
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Barad S, Sela N, Dubey AK, Kumar D, Luria N, Ment D, Cohen S, Schaffer AA, Prusky D. Differential gene expression in tomato fruit and Colletotrichum gloeosporioides during colonization of the RNAi-SlPH tomato line with reduced fruit acidity and higher pH. BMC Genomics 2017; 18:579. [PMID: 28778147 PMCID: PMC5545021 DOI: 10.1186/s12864-017-3961-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 07/25/2017] [Indexed: 01/15/2023] Open
Abstract
Background The destructive phytopathogen Colletotrichum gloeosporioides causes anthracnose disease in fruit. During host colonization, it secretes ammonia, which modulates environmental pH and regulates gene expression, contributing to pathogenicity. However, the effect of host pH environment on pathogen colonization has never been evaluated. Development of an isogenic tomato line with reduced expression of the gene for acidity, SlPH (Solyc10g074790.1.1), enabled this analysis. Total RNA from C. gloeosporioides colonizing wild-type (WT) and RNAi–SlPH tomato lines was sequenced and gene-expression patterns were compared. Results C. gloeosporioides inoculation of the RNAi–SlPH line with pH 5.96 compared to the WT line with pH 4.2 showed 30% higher colonization and reduced ammonia accumulation. Large-scale comparative transcriptome analysis of the colonized RNAi–SlPH and WT lines revealed their different mechanisms of colonization-pattern activation: whereas the WT tomato upregulated 13-LOX (lipoxygenase), jasmonic acid and glutamate biosynthesis pathways, it downregulated processes related to chlorogenic acid biosynthesis II, phenylpropanoid biosynthesis and hydroxycinnamic acid tyramine amide biosynthesis; the RNAi–SlPH line upregulated UDP-D-galacturonate biosynthesis I and free phenylpropanoid acid biosynthesis, but mainly downregulated pathways related to sugar metabolism, such as the glyoxylate cycle and L-arabinose degradation II. Comparison of C. gloeosporioides gene expression during colonization of the WT and RNAi–SlPH lines showed that the fungus upregulates ammonia and nitrogen transport and the gamma-aminobutyric acid metabolic process during colonization of the WT, while on the RNAi–SlPH tomato, it mainly upregulates the nitrate metabolic process. Conclusions Modulation of tomato acidity and pH had significant phenotypic effects on C. gloeosporioides development. The fungus showed increased colonization on the neutral RNAi–SlPH fruit, and limited colonization on the WT acidic fruit. The change in environmental pH resulted in different defense responses for the two tomato lines. Interestingly, the WT line showed upregulation of jasmonate pathways and glutamate accumulation, supporting the reduced symptom development and increased ammonia accumulation, as the fungus might utilize glutamate to accumulate ammonia and increase environmental pH for better expression of pathogenicity factors. This was not found in the RNAi–SlPH line which downregulated sugar metabolism and upregulated the phenylpropanoid pathway, leading to host susceptibility. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3961-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shiri Barad
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, 7505101, Rishon LeZion, Israel.,Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100, Rehovot, Israel
| | - Noa Sela
- Department of Plant Pathology and Weed Research, ARO, the Volcani Center, 50250, Bet Dagan, Israel
| | - Amit K Dubey
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, 7505101, Rishon LeZion, Israel
| | - Dilip Kumar
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, 7505101, Rishon LeZion, Israel
| | - Neta Luria
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, 7505101, Rishon LeZion, Israel
| | - Dana Ment
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, 7505101, Rishon LeZion, Israel
| | - Shahar Cohen
- Department of Plant Sciences, Agricultural Research Organization, the Volcani Center, 50250, Bet Dagan, Israel
| | - Arthur A Schaffer
- Department of Plant Sciences, Agricultural Research Organization, the Volcani Center, 50250, Bet Dagan, Israel
| | - Dov Prusky
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, 7505101, Rishon LeZion, Israel.
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Valueva TA, Zaichik BT, Kudryavtseva NN. Role of proteolytic enzymes in the interaction of phytopathogenic microorganisms with plants. BIOCHEMISTRY (MOSCOW) 2017; 81:1709-1718. [DOI: 10.1134/s0006297916130083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Tannous J, Atoui A, El Khoury A, Francis Z, Oswald IP, Puel O, Lteif R. A study on the physicochemical parameters for Penicillium expansum growth and patulin production: effect of temperature, pH, and water activity. Food Sci Nutr 2016; 4:611-22. [PMID: 27386110 PMCID: PMC4930504 DOI: 10.1002/fsn3.324] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 11/05/2015] [Accepted: 11/11/2015] [Indexed: 11/23/2022] Open
Abstract
Penicillium expansum is among the most ubiquitous fungi disseminated worldwide, that could threaten the fruit sector by secreting patulin, a toxic secondary metabolite. Nevertheless, we lack sufficient data regarding the growth and the toxigenesis conditions of this species. This work enables a clear differentiation between the favorable conditions to the P. expansum growth and those promising for patulin production. A mathematical model allowing the estimation of the P. expansum growth rate according to temperature, a W, and pH, was also developed. An optimal growth rate of 0.92 cm/day was predicted at 24°C with pH level of 5.1 and high a W level of 0.99. The model's predictive capability was tested successfully on artificial contaminated apples. This model could be exploited by apple growers and the industrialists of fruit juices in order to predict the development of P. expansum during storage and apple processing.
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Affiliation(s)
- Joanna Tannous
- Unité de Technologie et Valorisation AlimentaireCentre d'Analyses et de RechercheUniversité Saint‐JosephCampus des Sciences et TechnologiesMar Roukos, Mkallès, P.O Box 11‐ 514, Riad El Solh1107 2050BeirutLebanon
- Research Centre in Food ToxicologyINRAUMR 1331 Toxalim180 Chemin de TournefeuilleF‐31027Toulouse CedexFrance
- Université de Toulouse IIIENVTINPUMR 1331ToxalimF‐31076ToulouseFrance
| | - Ali Atoui
- Laboratory of Microorganisms and Food IrradiationLebanese Atomic Energy Commission‐CNRSP.O. Box 11‐8281, Riad El Solh1107 2260BeirutLebanon
- Department of BiologyFaculty of SciencesLaboratory of MicrobiologyLebanese UniversityHadath CampusBeirutLebanon
| | - André El Khoury
- Unité de Technologie et Valorisation AlimentaireCentre d'Analyses et de RechercheUniversité Saint‐JosephCampus des Sciences et TechnologiesMar Roukos, Mkallès, P.O Box 11‐ 514, Riad El Solh1107 2050BeirutLebanon
| | - Ziad Francis
- Unité de Technologie et Valorisation AlimentaireCentre d'Analyses et de RechercheUniversité Saint‐JosephCampus des Sciences et TechnologiesMar Roukos, Mkallès, P.O Box 11‐ 514, Riad El Solh1107 2050BeirutLebanon
| | - Isabelle P. Oswald
- Research Centre in Food ToxicologyINRAUMR 1331 Toxalim180 Chemin de TournefeuilleF‐31027Toulouse CedexFrance
- Université de Toulouse IIIENVTINPUMR 1331ToxalimF‐31076ToulouseFrance
| | - Olivier Puel
- Research Centre in Food ToxicologyINRAUMR 1331 Toxalim180 Chemin de TournefeuilleF‐31027Toulouse CedexFrance
- Université de Toulouse IIIENVTINPUMR 1331ToxalimF‐31076ToulouseFrance
| | - Roger Lteif
- Unité de Technologie et Valorisation AlimentaireCentre d'Analyses et de RechercheUniversité Saint‐JosephCampus des Sciences et TechnologiesMar Roukos, Mkallès, P.O Box 11‐ 514, Riad El Solh1107 2050BeirutLebanon
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Sharma M, Guleria S, Kulshrestha S. Diacylglycerol acyl transferase: A pathogenicity related gene in Colletotrichum gloeosporioides. J Basic Microbiol 2016; 56:1308-1315. [PMID: 27254647 DOI: 10.1002/jobm.201500663] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 05/08/2016] [Indexed: 11/06/2022]
Abstract
To gain more insight into the molecular mechanisms of Colletotrichum gloeosporioides pathogenesis, restriction enzyme-mediated integration (REMI) mutagenesis identified the mutants of C. gloeosporioides impaired in pathogenicity. Transformants screened for defects in pathogenicity using detached leaves and fruits. Of the 20 REMI transformants tested, two mutants (H4 and H7) showed reduced pathogenicity on leaves of apple, kiwi, mango, peach, and fruits of guava, apple, and capsicum. One tagged gene from the genome sequence of mutant H4 was recovered by inverse PCR. Sequence analysis of the tagged site in mutant H4 revealed insertion in diacylglycerol acyltransferase gene which encodes diacylglycerol acyltransferase enzyme, catalyzing the steps involved in the biosynthesis of triacylglycerol, an important component of biological membranes and source of energy. Therefore, tagging of diacylglycerol acyltransferase gene in mutant H4 resulted in reduced pathogenicity, indicating possible role of this gene in pathogenicity of C. gloeosporioides.
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Affiliation(s)
- Meenakshi Sharma
- Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Bajhol, Solan, Himachal Pradesh, India
| | - Shiwani Guleria
- Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Bajhol, Solan, Himachal Pradesh, India
| | - Saurabh Kulshrestha
- Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Bajhol, Solan, Himachal Pradesh, India
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Prusky DB, Bi F, Moral J, Barad S. How Does Host Carbon Concentration Modulate the Lifestyle of Postharvest Pathogens during Colonization? FRONTIERS IN PLANT SCIENCE 2016; 7:1306. [PMID: 27635125 PMCID: PMC5007722 DOI: 10.3389/fpls.2016.01306] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 08/15/2016] [Indexed: 05/10/2023]
Abstract
Postharvest pathogens can penetrate fruit by breaching the cuticle or directly through wounds, and they show disease symptoms only long after infection. During ripening and senescence, the fruit undergo physiological processes accompanied by a decline in antifungal compounds, which allows the pathogen to activate a mechanism of secretion of small effector molecules that modulate host environmental pH. These result in the activation of genes under their optimal pH conditions, enabling the fungus to use a specific group of pathogenicity factors at each particular pH. New research suggests that carbon availability in the environment is a key factor triggering the production and secretion of small pH-modulating molecules: ammonia and organic acids. Ammonia is secreted under limited carbon and gluconic acid under excess carbon. This mini review describes our most recent knowledge of the mechanism of activation of pH-secreted molecules and their contribution to colonization by postharvest pathogens to facilitate the transition from quiescence to necrotrophic lifestyle.
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Affiliation(s)
- Dov B Prusky
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center Beit Dagan, Israel
| | - Fangcheng Bi
- Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture Guangzhou, China
| | - Juan Moral
- Departamento de Agronomía, Universidad de Córdoba Córdoba, Spain
| | - Shiri Barad
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center Beit Dagan, Israel
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Huang W, Shang Y, Chen P, Gao Q, Wang C. MrpacC regulates sporulation, insect cuticle penetration and immune evasion inMetarhizium robertsii. Environ Microbiol 2014; 17:994-1008. [DOI: 10.1111/1462-2920.12451] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 01/30/2014] [Indexed: 01/04/2023]
Affiliation(s)
- Wei Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology; Institute of Plant Physiology and Ecology; Shanghai Institutes for Biological Sciences; Chinese Academy of Sciences; Shanghai 200032 China
| | - Yanfang Shang
- Key Laboratory of Insect Developmental and Evolutionary Biology; Institute of Plant Physiology and Ecology; Shanghai Institutes for Biological Sciences; Chinese Academy of Sciences; Shanghai 200032 China
| | - Peilin Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology; Institute of Plant Physiology and Ecology; Shanghai Institutes for Biological Sciences; Chinese Academy of Sciences; Shanghai 200032 China
| | - Qiang Gao
- Key Laboratory of Insect Developmental and Evolutionary Biology; Institute of Plant Physiology and Ecology; Shanghai Institutes for Biological Sciences; Chinese Academy of Sciences; Shanghai 200032 China
| | - Chengshu Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology; Institute of Plant Physiology and Ecology; Shanghai Institutes for Biological Sciences; Chinese Academy of Sciences; Shanghai 200032 China
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17
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Alkan N, Meng X, Friedlander G, Reuveni E, Sukno S, Sherman A, Thon M, Fluhr R, Prusky D. Global aspects of pacC regulation of pathogenicity genes in Colletotrichum gloeosporioides as revealed by transcriptome analysis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:1345-58. [PMID: 23902260 DOI: 10.1094/mpmi-03-13-0080-r] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Colletotrichum gloeosporioides alkalinizes its surroundings during colonization of host tissue. The transcription factor pacC is a regulator of pH-controlled genes and is essential for successful colonization. We present here the sequence assembly of the Colletotrichum fruit pathogen and use it to explore the global regulation of pathogenicity by ambient pH. The assembled genome size was 54 Mb, encoding 18,456 genes. Transcriptomes of the wild type and ΔpacC mutant were established by RNA-seq and explored for their global pH-dependent gene regulation. The analysis showed that pacC upregulates 478 genes and downregulates 483 genes, comprising 5% of the fungal genome, including transporters, antioxidants, and cell-wall-degrading enzymes. Interestingly, gene families with similar functionality are both up- and downregulated by pacC. Global analysis of secreted genes showed significant pacC activation of degradative enzymes at alkaline pH and during fruit infection. Select genes from alkalizing-type pathogen C. gloeosporioides and from acidifying-type pathogen Sclerotinia sclerotiorum were verified by quantitative reverse-transcription polymerase chain reaction analysis at different pH values. Knock out of several pacC-activated genes confirmed their involvement in pathogenic colonization of alkalinized surroundings. The results suggest a global regulation by pacC of key pathogenicity genes during pH change in alkalinizing and acidifying pathogens.
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18
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Abstract
SIGNIFICANCE Postharvest pathogens can start its attack process immediately after spores land on wounded tissue, whereas other pathogens can forcibly breach the unripe fruit cuticle and then remain quiescent for months until fruit ripens and then cause major losses. RECENT ADVANCES Postharvest fungal pathogens activate their development by secreting organic acids or ammonia that acidify or alkalinize the host ambient surroundings. CRITICAL ISSUES These fungal pH modulations of host environment regulate an arsenal of enzymes to increase fungal pathogenicity. This arsenal includes genes and processes that compromise host defenses, contribute to intracellular signaling, produce cell wall-degrading enzymes, regulate specific transporters, induce redox protectant systems, and generate factors needed by the pathogen to effectively cope with the hostile environment found within the host. Further, evidence is accumulating that the secreted molecules (organic acids and ammonia) are multifunctional and together with effect of the ambient pH, they activate virulence factors and simultaneously hijack the plant defense response and induce program cell death to further enhance their necrotrophic attack. FUTURE DIRECTIONS Global studies of the effect of secreted molecules on fruit pathogen interaction, will determine the importance of these molecules on quiescence release and the initiation of fungal colonization leading to fruit and vegetable losses.
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Affiliation(s)
- Noam Alkan
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot, Israel
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19
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Cnossen-Fassoni A, Bazzolli DMS, Brommonschenkel SH, Fernandes de Araújo E, de Queiroz MV. The pectate lyase encoded by the pecCl1 gene is an important determinant for the aggressiveness of Colletotrichum lindemuthianum. J Microbiol 2013; 51:461-70. [PMID: 23990297 DOI: 10.1007/s12275-013-3078-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 03/10/2013] [Indexed: 11/30/2022]
Abstract
Colletotrichum lindemuthianum is the causal agent of anthracnose in the common bean, and the genes that encode its cell-wall-degrading enzymes are crucial for the development of the disease. Pectinases are the most important group of cell wall-degrading enzymes produced by phytopathogenic fungi. The pecC1l gene, which encodes a pectate lyase in C. lindemuthianum, was isolated and characterized. Possible cis-regulatory elements and transcription factor binding sites that may be involved in the regulation of genetic expression were detected in the promoter region of the gene. pecCl1 is represented by a single copy in the genome of C. lindemuthianum, though in silico analyses of the genomes of Colletotrichum graminicola and Colletotrichum higginsianum suggest that the genome of C. lindemuthianum includes other genes that encode pectate lyases. Phylogenetic analysis detected two groups that clustered based on different members of the pectate lyase family. Analysis of the differential expression of pecCl1 during different stages of infection showed a significant increase in pecCl1 expression five days after infection, at the onset of the necrotrophic phase. The split-maker technique proved to be an efficient method for inactivation of the pecCl1 gene, which allowed functional study of a mutant with a site-specific integration. Though gene inactivation did not result in complete loss of pectate lyase activity, the symptoms of anthracnose were reduced. Analysis of pectate lyases might not only contribute to the understanding of anthracnose in the common bean but might also lead to the discovery of an additional target for controlling anthracnose.
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Affiliation(s)
- Andréia Cnossen-Fassoni
- Laboratory of Microorganism Molecular Genetics, Department of Microbiology/Institute of Microbiology Applied to Agriculture and Livestock Raising (BIOAGRO), Federal University of Viçosa, Viçosa-MG, Brazil
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20
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Shnaiderman C, Miyara I, Kobiler I, Sherman A, Prusky D. Differential activation of ammonium transporters during the accumulation of ammonia by Colletotrichum gloeosporioides and its effect on appressoria formation and pathogenicity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:345-355. [PMID: 23387470 DOI: 10.1094/mpmi-07-12-0170-r] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Ammonium secreted by the post-harvest pathogen Colletotrichum gloeosporioides during host colonization accumulates in the host environment due to enhanced fungal nitrogen metabolism. Two types of ammonium transporter-encoding genes, AMET and MEP, are expressed during pathogenicity. Gene disruption of AMET, a gene modulating ammonia secretion, showed twofold reduced ammonia secretion and 45% less colonization on avocado fruit, suggesting a contribution to pathogenicity. MEPB, a gene modulating ammonium transport, is expressed by C. gloeosporioides during pathogenicity and starvation conditions in culture. Gene disruption of MEPB, the most highly expressed gene of the MEP family, resulted in twofold overexpression of MEPA and MEPC but reduced colonization, suggesting MEPB expression's contribution to pathogenicity. Analysis of internal and external ammonia accumulation by ΔmepB strains in mycelia and germinated spores showed rapid uptake and accumulation, and reduced secretion of ammonia in the mutant versus wild-type (WT) strains. Ammonia uptake by the WT germinating spores but not by the ΔmepB strain with compromised ammonium transport activated cAMP and transcription of PKA subunits PKAR and PKA2. ΔmepB mutants showed 75% less appressorium formation and colonization than the WT, which was partially restored by 10 mM exogenous ammonia. Thus, whereas both AMET and MEPB genes modulate ammonia secretion, only MEPB contributes to ammonia accumulation by mycelia and germinating spores that activate the cAMP pathways, inducing the morphogenetic processes contributing to C. gloeosporioides pathogenicity.
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Affiliation(s)
- Chen Shnaiderman
- Department of Postharvest Science of Fresh Produce, ARO, Bet Dagan, Israel
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21
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PacC and pH-dependent transcriptome of the mycotrophic fungus Trichoderma virens. BMC Genomics 2013; 14:138. [PMID: 23445374 PMCID: PMC3618310 DOI: 10.1186/1471-2164-14-138] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Accepted: 02/23/2013] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND In fungi, environmental pH is an important signal for development, and successful host colonization depends on homeostasis. Surprisingly, little is known regarding the role of pH in fungal-fungal interactions. Species of Trichoderma grow as soil saprobes but many are primarily mycotrophic, using other fungi as hosts. Therefore, Trichoderma spp. are studied for their potential in biocontrol of plant diseases. Particularly in alkaline soil, pH is a critical limiting factor for these biofungicides, whose optimal growth pH is 4-6. Gaining an understanding of pH adaptability is an important step in broadening the activity spectrum of these economically important fungi. RESULTS We studied the pH-responsive transcription factor PacC by gene knockout and by introduction of a constitutively active allele (pacCc). ΔpacC mutants exhibited reduced growth at alkaline pH, while pacCc strains grew poorly at acidic pH. In plate confrontation assays ΔpacC mutants showed decreased ability to compete with the plant pathogens Rhizoctonia solani and Sclerotium rolfsii. The pacCc strain exhibited an overgrowth of R. solani that was comparable to the wild type, but was unable to overgrow S. rolfsii. To identify genes whose expression is dependent on pH and pacC, we designed oligonucleotide microarrays from the transcript models of the T. virens genome, and compared the transcriptomes of wild type and mutant cultures exposed to high or low pH. Transcript levels from several functional classes were dependent on pacC, on pH, or on both. Furthermore, the expression of a set of pacC-dependent genes was increased in the constitutively-active pacCc strain, and was pH-independent in some, but not all cases. CONCLUSIONS PacC is important for biocontrol-related antagonism of other fungi by T. virens. As much as 5% of the transcriptome is pH-dependent, and of these genes, some 25% depend on pacC. Secondary metabolite biosynthesis and ion transport are among the relevant gene classes. We suggest that ΔpacC mutants may have lost their full biocontrol potential due to their inability to adapt to alkaline pH, to perceive ambient pH, or both. The results raise the novel possibility of genetically manipulating Trichoderma in order to improve adaptability and biocontrol at alkaline pH.
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Prusky D, Alkan N, Mengiste T, Fluhr R. Quiescent and necrotrophic lifestyle choice during postharvest disease development. ANNUAL REVIEW OF PHYTOPATHOLOGY 2013; 51:155-76. [PMID: 23682917 DOI: 10.1146/annurev-phyto-082712-102349] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Insidious fungal infections by postharvest pathogens remain quiescent during fruit growth until, at a particular phase during fruit ripening and senescence, the pathogens switch to the necrotrophic lifestyle and cause decay. During ripening, fruits undergo physiological processes, such as activation of ethylene biosynthesis, cuticular changes, and cell-wall loosening-changes that are accompanied by a decline of antifungal compounds, both those that are preformed and those that are inducible secondary metabolites. Pathogen infection of the unripe host fruit initiates defensive signal-transduction cascades, culminating in accumulation of antifungal proteins that limit fungal growth and development. In contrast, development of the same pathogens during fruit ripening and storage activates a substantially different signaling network, one that facilitates aggressive fungal colonization. This review focuses on responses induced by the quiescent pathogens of postharvest diseases in unripe host fruits. New genome-scale experimental approaches have begun to delineate the complex and multiple networks of host and pathogen responses activated to maintain or to facilitate the transition from the quiescent to the necrotrophic lifestyle.
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Affiliation(s)
- Dov Prusky
- Department of Postharvest Science of Fresh Produce, ARO, Volcani Center, Bet Dagan, 50250 Israel.
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Miyara I, Shnaiderman C, Meng X, Vargas WA, Diaz-Minguez JM, Sherman A, Thon M, Prusky D. Role of nitrogen-metabolism genes expressed during pathogenicity of the alkalinizing Colletotrichum gloeosporioides and their differential expression in acidifying pathogens. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2012; 25:1251-63. [PMID: 22571816 DOI: 10.1094/mpmi-01-12-0017-r] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Pathogens can actively alter fruit pH around the infection site, signaling modulation of pathogenicity-factor expression, as found for alkalinizing (Colletotrichum and Alternaria spp.) and acidifying (Penicillium, Botrytis, and Sclerotinia spp.) fungi. The nitrogen-metabolism genes GDH2, GS1, GLT, and MEP genes are differentially expressed during colonization by Colletotrichum gloeosporioides, and a Δgdh2 strain reduces ammonia accumulation and pathogenicity. We analyzed the contribution of transporters GLT and MEPB to C. gloeosporiodes pathogenicity. Germinating spores of Δglt strains showed reduced appressorium formation; those of ΔmepB mutants showed rapid ammonia uptake and accumulation inside the hyphae, indicating deregulated uptake. Both mutants reduced pathogenicity, indicating that these transporters function during alkalinizing species pathogenicity. We compared the expressions of these genes in C. gloeosporioides and Sclerotinia sclerotiorum, and found five to 10-fold higher expression at the transcript level in the former. Interestingly, GLT and MEPB in the alkalinizing species showed no and very low sequence identity, respectively, with their counterparts in the acidifying species. Knockout analysis of GLT and MEPB and their differential transcript regulation in the alkalinizing and acidifying species suggest that the ammonia accumulation contributing to pathogenicity in the former is modulated by factors at the gene-regulation levels that are lacking in the acidifying species.
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Affiliation(s)
- I Miyara
- Department of Postharvest Science of Fresh Produce, ARO, Bet Dagan, Israel
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Ben-Daniel BH, Bar-Zvi D, Tsror Lahkim L. Pectate lyase affects pathogenicity in natural isolates of Colletotrichum coccodes and in pelA gene-disrupted and gene-overexpressing mutant lines. MOLECULAR PLANT PATHOLOGY 2012; 13:187-97. [PMID: 21848609 PMCID: PMC6638648 DOI: 10.1111/j.1364-3703.2011.00740.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Colletotrichum coccodes (Wallr.) S. Hughes, the causal agent of black dot on potato and anthracnose on tomato, reduces yield and crop quality. We explored the role of secreted pectate lyase (PL), a cell wall-degrading enzyme, in the aggressiveness of C. coccodes. In vitro-cultivated highly aggressive isolates secreted immunologically detectable PL levels 6 h after transfer to secondary medium versus 12 h for mildly aggressive isolates, suggesting that secreted PL is a virulence factor. The gene encoding PL, CcpelA, was cloned and used for the genetic manipulation of highly (US-41 and Si-72) and mildly (Si-60) aggressive isolates. CcpelA gene-disrupted mutants showed reduced aggressiveness towards tomato fruits and impaired PL secretion and extracellular activity. Conversely, overexpression of CcpelA in the Si-60 isolate increased its aggressiveness and PL secretion. Comparison of CcpelA cloned from isolates US-41 and Si-60 revealed that both encode identical proteins, but differ in their promoters. Bioinformatics analysis for cis-acting elements suggested that the promoters of the US-41 and Si-60 isolates contain one and no AreA-binding site (GATA box), respectively. AreA has been suggested to be involved in fungal aggressiveness; therefore, CcpelA may be a key virulence factor in C. coccodes pathogenicity, and the differences in isolate aggressiveness might result from promoter activity. Quantitative reverse transcriptase-polymerase chain reaction analyses confirmed the higher level of CcpelA transcript in isolate US-41 versus Si-60.
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Affiliation(s)
- Bat-Hen Ben-Daniel
- Department of Plant Pathology, Agricultural Research Organization, Gilat Research Center, MP Negev 85280, Israel
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Alkan N, Fluhr R, Prusky D. Ammonium secretion during Colletotrichum coccodes infection modulates salicylic and jasmonic acid pathways of ripe and unripe tomato fruit. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2012; 25:85-96. [PMID: 22150075 DOI: 10.1094/mpmi-01-11-0020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The postharvest pathogens Colletotrichum coccodes remains quiescent after infection of unripe fruit. However, during fruit ripening, the pathogen assumes a necrotrophic life style, rapidly colonizing the tissue. C. coccodes secretes ammonium during germination and colonization of host tissue that induces host programmed cell death. We further examined the role of ammonia in the infection process by analyzing transcriptome expression from infected and ammonia-treated fruit tissue compared with healthy tissue. The analysis revealed 82 and 237 common upregulated and downregulated genes, respectively. Quantitative reverse-transcriptase polymerase chain reaction analysis of select transcripts in normal and transgenic NADPH oxidase antisense plants revealed that their expression was NADPH oxidase dependent. Common-upregulated genes showed overrepresentation of salicylic acid (SA)-dependent genes as well as genes related to biotic stress. The downregulated genes showed overrepresentation of jasmonic acid (JA)-dependent genes. Indeed, direct application of SA to the fruit enhanced C. coccodes necrotrophic colonization, whereas the application of JA delayed colonization. Importantly, green fruit and red fruit displayed similar gene expression patterns although only red fruit is susceptible to colonization. Thus, it is likely that the resistance of green fruit to C. coccodes colonization is due to additional factors.
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Affiliation(s)
- Noam Alkan
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, Bet Dagan, Israel
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Effantin G, Rivasseau C, Gromova M, Bligny R, Hugouvieux-Cotte-Pattat N. Massive production of butanediol during plant infection by phytopathogenic bacteria of the genera Dickeya and Pectobacterium. Mol Microbiol 2011; 82:988-97. [PMID: 22032684 DOI: 10.1111/j.1365-2958.2011.07881.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Plant pathogenic bacteria of the genera Dickeya and Pectobacterium are broad-host-range necrotrophs which cause soft-rot diseases in important crops. A metabolomic analysis, based on (13)C-NMR spectroscopy, was used to characterize the plant-bacteria interaction. Metabolic profiles revealed a decline in plant sugars and amino acids during infection and the concomitant appearance of a compound identified as 2,3-butanediol. Butanediol is the major metabolite found in macerated tissues of various host plants. It is accumulated during the symptomatic phase of the disease. Different species of Dickeya or Pectobacterium secrete high levels of butanediol during plant infection. Butanediol has been described as a signalling molecule involved in plant/bacterium interactions and, notably, able to induce plant systemic resistance. The bud genes, involved in butanediol production, are conserved in the phytopathogenic enterobacteria of the genera Dickeya, Pectobacterium, Erwinia, Pantoea and Brenneria. Inactivation of the bud genes of Dickeya dadantii revealed that the virulence of budA, budB and budR mutants was clearly reduced. The genes budA, budB and budC are highly expressed during plant infection. These data highlight the importance of butanediol metabolism in limiting acidification of the plant tissue during the development of the soft-rot disease caused by pectinolytic enterobacteria.
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Affiliation(s)
- Géraldine Effantin
- Université de Lyon, Université Lyon 1, INSA-Lyon, Microbiologie Adaptation et Pathogénie, CNRS UMR5240, Domaine Scientifique de la Doua, 69622 Villeurbanne, France
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Marquez-Villavicencio MDP, Weber B, Witherell RA, Willis DK, Charkowski AO. The 3-hydroxy-2-butanone pathway is required for Pectobacterium carotovorum pathogenesis. PLoS One 2011; 6:e22974. [PMID: 21876734 PMCID: PMC3158072 DOI: 10.1371/journal.pone.0022974] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 07/05/2011] [Indexed: 11/19/2022] Open
Abstract
Pectobacterium species are necrotrophic bacterial pathogens that cause soft rot diseases in potatoes and several other crops worldwide. Gene expression data identified Pectobacterium carotovorum subsp. carotovorum budB, which encodes the α-acetolactate synthase enzyme in the 2,3-butanediol pathway, as more highly expressed in potato tubers than potato stems. This pathway is of interest because volatiles produced by the 2,3-butanediol pathway have been shown to act as plant growth promoting molecules, insect attractants, and, in other bacterial species, affect virulence and fitness. Disruption of the 2,3-butanediol pathway reduced virulence of P. c. subsp. carotovorum WPP14 on potato tubers and impaired alkalinization of growth medium and potato tubers under anaerobic conditions. Alkalinization of the milieu via this pathway may aid in plant cell maceration since Pectobacterium pectate lyases are most active at alkaline pH.
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Affiliation(s)
| | - Brooke Weber
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - R. Andrews Witherell
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - David K. Willis
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Vegetable Crops Research Unit, Agricultural Research Service, United States Department of Agriculture, Madison, Wisconsin, United States of America
| | - Amy O. Charkowski
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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Miyara I, Shafran H, Davidzon M, Sherman A, Prusky D. pH Regulation of ammonia secretion by Colletotrichum gloeosporioides and its effect on appressorium formation and pathogenicity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:304-16. [PMID: 20121452 DOI: 10.1094/mpmi-23-3-0304] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Host-tissue alkalinization via ammonia accumulation is key to Colletotrichum spp. colonization. Using macroarrays carrying C. gloeosporioides cDNAs, we monitored gene expression during the alkalinization process. A set of genes involved in synthesis and catabolism of ammonia accumulation were identified. Expression of NAD(+)-specific glutamate dehydrogenase (GDH2, encoding ammonia synthesis) and the ammonia exporter AMET were induced at pH 4.0 to 4.5. Conversely, ammonia uptake and transcript activation of the ammonia and glutamate importers (MEP and GLT, respectively) and glutamine synthase (GS1) were higher at pH 6.0 to 7.0. Accumulated ammonia in the wild-type mycelium decreased during ambient alkalinization, concurrent with increased GS1 expression. Deltapac1 mutants of C. gloeosporioides, which are sensitive to alkaline pH changes, showed upregulation of the acid-expressed GDH2 and downregulation of the alkaline-expressed GS1, resulting in 60% higher ammonia accumulation inside the mycelium. Deltagdh2 strains of C. gloeosporioides, impaired in ammonia production, showed 85% inhibition in appressorium formation followed by reduced colonization on avocado fruit (Persea americana cv. Fuerte) pericarp, while exogenic ammonia addition restored appressoria formation. Thus the modulation of genes involved in ammonia metabolism and catabolism by C. gloeosporioides is ambient pH-dependent. Aside from its contribution to necrotrophic stages, ammonia accumulation by germinating spores regulates appressorium formation and determines the initiation of biotrophic stages of avocado-fruit colonization by Colletotrichum spp.
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Affiliation(s)
- Itay Miyara
- Department Of Postharvest Sciences Of Fresh Produce, Agricultural Reserach Organization, The Volcani Center, Bet Dagan 50250, Israel
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Diéguez-Uribeondo J, Förster H, Adaskaveg JE. Visualization of localized pathogen-Induced pH modulation in almond tissues infected by Colletotrichum acutatum using confocal scanning laser microscopy. PHYTOPATHOLOGY 2008; 98:1171-8. [PMID: 18943405 DOI: 10.1094/phyto-98-11-1171] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Modulation of pH within the host during infection of almond by the anthracnose pathogen Colletotrichum acutatum was studied using confocal scanning laser microscopy and the dual emission fluorescence indicator SNARF-1. This highly sensitive method allowed visualization of the spatial distribution of localized pathogen-induced pH modulation within and in proximity to fungal infection structures in host tissue at the cellular level. Ratiometric measurement of fluorescence at two emission wavelengths and in situ calibration allowed the quantification of pH ranges. After incubation of leaf epidermal tissue with SNARF-1, distinct alkaline (pH 8 to > or =9), red-spectrum (650 nm wave length) fluorescent zones developed as partial or complete halos around many fungal appressoria and in infection vesicles at 24 to 36 h after inoculation. In samples taken after 48 to 72 h, colonizing hyphae in the biotrophic phase and subsequently in the necrotrophic phase were also emitting the red fluorescence that extended into the surrounding host tissue, as also verified by depth analyses. Host epidermal cells were intact and apparently alive during the fungal alkalization process, with no visible disruption of cell structure. Generally, the pH of epidermal cells in noninoculated samples or in areas away from the infection in inoculated samples was lower than pH 7 with green (i.e., 500 to 550 nm wave length) fluorescence detected. Using standard electrodes, a significant increase in pH and ammonia concentration in leaf and fruit tissue was also measured but only at advanced stages of disease. In contrast, hyphae of the pathogen Alternaria alternata were mostly acidic and no change in fluorescence was found inside invaded host cells. The sequence of events in the C. acutatum-almond interaction includes penetration, production of ammonia by C. acutatum, and subsequent pH modulation within almond epidermal tissue to an alkaline environment that leads to further colonization of the host.
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Alkan N, Fluhr R, Sherman A, Prusky D. Role of ammonia secretion and pH modulation on pathogenicity of Colletotrichum coccodes on tomato fruit. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2008; 21:1058-66. [PMID: 18616402 DOI: 10.1094/mpmi-21-8-1058] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Colletotrichum coccodes was found to alkalinize the decaying tissue of tomato fruit via accumulation and secretion of ammonia. Alkalinization dynamics caused by ammonia secretion from growing hyphae was examined microscopically using the pH-sensitive fluorescent dye 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. Values of pH of 7.9 observed in the host tissue close to the hyphal tips declined to pH 6.0 at 10 mm away from the hyphal tip, which was a value that was still higher than that detected in the healthy tissue, pH 4.2. Ammonia accumulation at the infection site depended on the initial environmental pH. Treatments with low (4.0) pH buffer at the infection site resulted in high levels of ammonia secretion and increased virulence of C. coccodes compared with similar treatments with buffer at pH 7.0. Significantly, mutants of C. coccodes defective in nitrogen utilization, nit-, and areA- were impaired in ammonia secretion and showed reduced decay development. The reduced infection rate of nit- mutants could be complemented by adding glutamine at the infection site. Thus, ammonia accumulation is a critical factor contributing to C. coccodes pathogenicity on tomato fruit. The results show that the initial acidic pH of the fruit is conducive to ammonia secretion and the subsequent alkalinization of the infection site, and facilitates fungal virulence and the transformation from the quiescent-biotrophic to active-necrotrophic state.
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Affiliation(s)
- N Alkan
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, Bet Dagan, Israel
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Miyara I, Shafran H, Kramer Haimovich H, Rollins J, Sherman A, Prusky D. Multi-factor regulation of pectate lyase secretion by Colletotrichum gloeosporioides pathogenic on avocado fruits. MOLECULAR PLANT PATHOLOGY 2008; 9:281-91. [PMID: 18705870 PMCID: PMC6640356 DOI: 10.1111/j.1364-3703.2007.00462.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Tissue alkalinization during Colletotrichum gloeosporioides attack enhances the expression of PELB, which encodes pectate lyase (PL), and PL secretion, which is considered essential for full virulence. We studied the regulation of PL secretion by manipulation of C. gloeosporioides PELB. PELB was down-regulated by knocking out PAC1, which encodes the PacC transcription factor that regulates gene products with pH-sensitive activities. We functionally characterized a PACC gene homologue, PAC1, from C. gloeosporioides wild-type (WT) Cg-14 and two independent deletion strains, Deltapac1(372)and Deltapac1(761). Loss-of-function PAC1 mutants showed 85% reduction of PELB transcript expression, delayed PL secretion and dramatically reduced virulence, as detected in infection assays with avocado fruits. In contrast, PELB was up-regulated in the presence of carbon sources such as glucose. When glucose was used as a carbon source in the medium for the WT strain and the Deltapac1 mutant at pH 6.0, PELB transcript expression and PL secretion were activated. Other sugars, such as sucrose and fructose (but not galactose), also activated PELB expression. These results suggest that the pH-regulated response is only part of a multi-factor regulation of PELB, and that sugars are also needed to promote the transition from quiescent to active necrotrophic development by the pathogen.
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Affiliation(s)
- I Miyara
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
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Shafran H, Miyara I, Eshed R, Prusky D, Sherman A. Development of new tools for studying gene function in fungi based on the Gateway system. Fungal Genet Biol 2008; 45:1147-54. [PMID: 18550398 DOI: 10.1016/j.fgb.2008.04.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Revised: 03/24/2008] [Accepted: 04/06/2008] [Indexed: 10/22/2022]
Abstract
Genomic information of many fungi has been released but large scale functional genomic studies are still limited by a lack of high-throughput methods. The low rates of homologous recombination and low rates of transformation are limiting steps in filamentous fungi, but the molecular tools are also lagging behind. In this paper we describe two new high-throughput functional genomic tools for filamentous fungi that are based on the Gateway technology. One system is the Gateway RNAi vector for fungi that allows gene silencing in a high-throughput manner. The other system is a high-throughput deletion construct system. These systems were tested using the PAC1 gene of Colletotrichum gloeosporioides. Using these types of approaches, large scale functional genomics experiments can be performed in filamentous fungi.
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Affiliation(s)
- Hadas Shafran
- Department of Genomics, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
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Prusky D, Lichter A. Activation of quiescent infections by postharvest pathogens during transition from the biotrophic to the necrotrophic stage. FEMS Microbiol Lett 2007; 268:1-8. [PMID: 17227463 DOI: 10.1111/j.1574-6968.2006.00603.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Insidious fungal infections of postharvest pathogens remain quiescent, as biotrophs, during fruit growth and harvest, but activate their development and transform to necrotrophs, which elicit decay symptoms, during ripening and senescence. Exposure of unripe hosts to pathogens quickly initiates defensive signal-transduction cascades that limit fungal growth and development, but exposure to the same pathogens during ripening and storage activates a substantially different signaling cascade that facilitates fungal colonization. The first step in the activation of quiescent infections may involve the fungal capability to cope with plant defense responses by detoxification and efflux transport of antifungals, or by overcoming the suppression of pathogenicity factors. The second step toward the activation of quiescent infections is actively modulated by the pathogen in response to a host signal(s), and includes alkalization or ammonification of the host tissue, which sensitizes the host and activates the transcription and secretion of fungal-degradative enzymes that promote maceration of the host tissue. Feedback signals involving, for example, nitrogen and sugar further enhance pH changes, synthesis of hydrolytic enzymes and saprophytic development in the macerated tissue. This review describes the coordinated series of mechanisms that regulate the activation of quiescent infections in various fruit/vegetable-pathogen interactions.
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Affiliation(s)
- Dov Prusky
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, Bet Dagan, Israel.
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