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Zhang K, Wang W, Yang Q. Transcriptome Analysis Reveals the Regulation of Aureobasidium pullulans under Different pH Stress. Int J Mol Sci 2023; 24:16103. [PMID: 38003294 PMCID: PMC10671783 DOI: 10.3390/ijms242216103] [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: 10/10/2023] [Revised: 11/01/2023] [Accepted: 11/03/2023] [Indexed: 11/26/2023] Open
Abstract
Aureobasidium pullulans (A. pullulans), a commonly found yeast-like fungus, exhibits adaptability to a wide range of pH environments. However, the specific mechanisms and regulatory pathways through which A. pullulans respond to external pH remain to be fully understood. In this study, we first sequenced the whole genome of A. pullulans using Nanopore technology and generated a circle map. Subsequently, we explored the biomass, pullulan production, melanin production, and polymalic acid production of A. pullulans when cultivated at different pH levels. We selected pH 4.0, pH 7.0, and pH 10.0 to represent acidic, neutral, and alkaline environments, respectively, and examined the morphological characteristics of A. pullulans using SEM and TEM. Our observations revealed that A. pullulans predominantly exhibited hyphal growth with thicker cell walls under acidic conditions. In neutral environments, it primarily displayed thick-walled spores and yeast-like cells, while in alkaline conditions, it mainly assumed an elongated yeast-like cell morphology. Additionally, transcriptome analysis unveiled that A. pullulans orchestrates its response to shifts in environmental pH by modulating its cellular morphology and the expression of genes involved in pullulan, melanin, and polymalic acid synthesis. This research enhances the understanding of how A. pullulans regulates itself in diverse pH settings and offers valuable guidance for developing and applying engineered strains.
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Affiliation(s)
- Kai Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150006, China
| | - Wan Wang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150006, China
| | - Qian Yang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150006, China
- State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China
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Jeyaraj A, Elango T, Chen X, Zhuang J, Wang Y, Li X. Advances in understanding the mechanism of resistance to anthracnose and induced defence response in tea plants. MOLECULAR PLANT PATHOLOGY 2023; 24:1330-1346. [PMID: 37522519 PMCID: PMC10502868 DOI: 10.1111/mpp.13354] [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: 03/12/2023] [Revised: 05/03/2023] [Accepted: 05/04/2023] [Indexed: 08/01/2023]
Abstract
The tea plant (Camellia sinensis) is susceptible to anthracnose disease that causes considerable crop loss and affects the yield and quality of tea. Multiple Colletotrichum spp. are the causative agents of this disease, which spreads quickly in warm and humid climates. During plant-pathogen interactions, resistant cultivars defend themselves against the hemibiotrophic pathogen by activating defence signalling pathways, whereas the pathogen suppresses plant defences in susceptible varieties. Various fungicides have been used to control this disease on susceptible plants, but these fungicide residues are dangerous to human health and cause fungicide resistance in pathogens. The problem-solving approaches to date are the development of resistant cultivars and ecofriendly biocontrol strategies to achieve sustainable tea cultivation and production. Understanding the infection stages of Colletotrichum, tea plant resistance mechanisms, and induced plant defence against Colletotrichum is essential to support sustainable disease management practices in the field. This review therefore summarizes the current knowledge of the identified causative agent of tea plant anthracnose, the infection strategies and pathogenicity of C. gloeosporioides, anthracnose disease resistance mechanisms, and the caffeine-induced defence response against Colletotrichum infection. The information reported in this review will advance our understanding of host-pathogen interactions and eventually help us to develop new disease control strategies.
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Affiliation(s)
- Anburaj Jeyaraj
- College of HorticultureNanjing Agricultural UniversityNanjingChina
| | | | - Xuan Chen
- College of HorticultureNanjing Agricultural UniversityNanjingChina
| | - Jing Zhuang
- College of HorticultureNanjing Agricultural UniversityNanjingChina
| | - Yuhua Wang
- College of HorticultureNanjing Agricultural UniversityNanjingChina
| | - Xinghui Li
- College of HorticultureNanjing Agricultural UniversityNanjingChina
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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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Lopez-Ortiz C, Reddy UK, Zhang C, Natarajan P, Nimmakayala P, Benedito VA, Fabian M, Stommel J. QTL and PACE analyses identify candidate genes for anthracnose resistance in tomato. FRONTIERS IN PLANT SCIENCE 2023; 14:1200999. [PMID: 37615029 PMCID: PMC10443646 DOI: 10.3389/fpls.2023.1200999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 07/17/2023] [Indexed: 08/25/2023]
Abstract
Anthracnose, caused by the fungal pathogen Colletotrichum spp., is one of the most significant tomato diseases in the United States and worldwide. No commercial cultivars with anthracnose resistance are available, limiting resistant breeding. Cultivars with genetic resistance would significantly reduce crop losses, reduce the use of fungicides, and lessen the risks associated with chemical application. A recombinant inbred line (RIL) mapping population (N=243) has been made from a cross between the susceptible US28 cultivar and the resistant but semiwild and small-fruited 95L368 to identify quantitative trait loci (QTLs) associated with anthracnose resistance. The RIL population was phenotyped for resistance by inoculating ripe field-harvested tomato fruits with Colletotrichum coccodes for two seasons. In this study, we identified twenty QTLs underlying resistance, with a range of phenotypic variance of 4.5 to 17.2% using a skeletal linkage map and a GWAS. In addition, a QTLseq analysis was performed using deep sequencing of extreme bulks that validated QTL positions identified using traditional mapping and resolved candidate genes underlying various QTLs. We further validated AP2-like ethylene-responsive transcription factor, N-alpha-acetyltransferase (NatA), cytochrome P450, amidase family protein, tetratricopeptide repeat, bHLH transcription factor, and disease resistance protein RGA2-like using PCR allelic competitive extension (PACE) genotyping. PACE assays developed in this study will enable high-throughput screening for use in anthracnose resistance breeding in tomato.
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Affiliation(s)
- Carlos Lopez-Ortiz
- Department of Biology, Gus R. Douglass Institute, West Virginia State University, Institute, WV, United States
| | - Umesh K. Reddy
- Department of Biology, Gus R. Douglass Institute, West Virginia State University, Institute, WV, United States
| | - Chong Zhang
- The Genetic Improvement for Fruits & Vegetables Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, MD, United States
| | - Purushothaman Natarajan
- Department of Biology, Gus R. Douglass Institute, West Virginia State University, Institute, WV, United States
| | - Padma Nimmakayala
- Department of Biology, Gus R. Douglass Institute, West Virginia State University, Institute, WV, United States
| | | | - Matthew Fabian
- The Genetic Improvement for Fruits & Vegetables Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, MD, United States
| | - John Stommel
- The Genetic Improvement for Fruits & Vegetables Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, MD, United States
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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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Vieira A, Silva DN, Várzea V, Paulo OS, Batista D. Genome-Wide Signatures of Selection in Colletotrichum kahawae Reveal Candidate Genes Potentially Involved in Pathogenicity and Aggressiveness. Front Microbiol 2019; 10:1374. [PMID: 31275287 PMCID: PMC6593080 DOI: 10.3389/fmicb.2019.01374] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 06/03/2019] [Indexed: 12/26/2022] Open
Abstract
Plants and their pathogens are engaged in continuous evolutionary battles, with pathogens evolving to circumvent plant defense mechanisms and plants responding through enhanced protection to prevent or mitigate damage induced by pathogen attack. Managed ecosystems are composed of genetically identical populations of crop plants with few changes from year to year. These environments are highly conducive to the emergence and dissemination of pathogens and they exert selective pressure for both qualitative virulence factors responsible for fungal pathogenicity, and quantitative traits linked to pathogen fitness, such as aggressiveness. In this study, we used a comparative genome-wide approach to investigate the genomic basis underlying the pathogenicity and aggressiveness of the fungal coffee pathogen Colletotrichum kahawae infecting green coffee berries. The pathogenicity was investigated by comparing genomic variation between C. kahawae and its non-pathogenic sibling species, while the aggressiveness was studied by a genome-wide association approach with groups of isolates with different phenotypic profiles. High genetic differentiation was observed between C. kahawae and the most closely related species with 5,560 diagnostic SNPs identified, in which a significant enrichment of non-synonymous mutations was detected. Functional annotation of these non-synonymous mutations revealed a significant enrichment mainly in two gene ontology categories, “oxidation–reduction process” and “integral component of membrane.” Finally, the annotation of several genes potentially under-selection revealed that C. kahawae’s pathogenicity may be a complex biological process, in which important biological functions, such as, detoxification and transport, regulation of host and pathogen gene expression, and signaling are involved. On the other hand, the genome-wide association analyses for aggressiveness were able to identify 10 SNPs and 15 SNPs of small effect in single and multi-association analysis, respectively, from which 7 were common, giving in total 18 SNPs potentially associated. The annotation of these genomic regions allowed the identification of four candidate genes encoding F-box domain-containing, nitrosoguanidine resistance, Fungal specific transcription factor domain-containing and C6 transcription factor that could be associated with aggressiveness. This study shed light, for the first time, on the genetic mechanisms of C. kahawae host specialization.
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Affiliation(s)
- Ana Vieira
- Centro de Investigação das Ferrugens do Cafeeiro, Instituto Superior de Agronomia, Universidade de Lisboa, Oeiras, Portugal.,Computational Biology and Population Genomics Group, Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal.,Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, Lisbon, Portugal
| | - Diogo Nuno Silva
- Centro de Investigação das Ferrugens do Cafeeiro, Instituto Superior de Agronomia, Universidade de Lisboa, Oeiras, Portugal.,Computational Biology and Population Genomics Group, Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal.,Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, Lisbon, Portugal
| | - Vitor Várzea
- Centro de Investigação das Ferrugens do Cafeeiro, Instituto Superior de Agronomia, Universidade de Lisboa, Oeiras, Portugal.,Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, Lisbon, Portugal
| | - Octávio Salgueiro Paulo
- Computational Biology and Population Genomics Group, Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Dora Batista
- Centro de Investigação das Ferrugens do Cafeeiro, Instituto Superior de Agronomia, Universidade de Lisboa, Oeiras, Portugal.,Computational Biology and Population Genomics Group, Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal.,Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, Lisbon, Portugal
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Sánchez-Rangel D, Hernández-Domínguez EE, Pérez-Torres CA, Ortiz-Castro R, Villafán E, Rodríguez-Haas B, Alonso-Sánchez A, López-Buenfil A, Carrillo-Ortiz N, Hernández-Ramos L, Ibarra-Laclette E. Environmental pH modulates transcriptomic responses in the fungus Fusarium sp. associated with KSHB Euwallacea sp. near fornicatus. BMC Genomics 2018; 19:721. [PMID: 30285612 PMCID: PMC6167834 DOI: 10.1186/s12864-018-5083-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 09/17/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The Ambrosia Fusarium Clade phytopathogenic Fusarium fungi species have a symbiotic relationship with ambrosia beetles in the genus Euwallacea (Coleoptera: Curculionidae). Related beetle species referred to as Euwallacea sp. near fornicatus have been spread in California, USA and are recognized as the causal agents of Fusarium dieback, a disease that causes mortality of many plant species. Despite the importance of this fungi, no transcriptomic resources have been generated. The datasets described here represent the first ever transcripts available for these species. We focused our study on the isolated species of Fusarium that is associated with one of the cryptic species referred to as Kuroshio Shot Hole Borer (KSHB) Euwallacea sp. near fornicatus. RESULTS Hydrogen concentration is a critical signal in fungi for growth and host colonization, the aim of this study was to evaluate the effect of different pH conditions on growth and gene expression of the fungus Fusarium sp. associated with KSHB. An RNA-seq approach was used to compare the gene expression of the fungus grown for 2 weeks in liquid medium at three different pH levels (5.0, 6.0, and 7.0). An unbuffered treatment was included to evaluate the capability of the fungus to change the pH of its environment and the impact in gene expression. The results showed that the fungus can grow and modulate its genetic expression at different pH conditions; however, growth was stunted in acidic pH in comparison with neutral pH. The results showed a differential expression pattern in each pH condition even when acidic conditions prevailed at the end of the experiment. After comparing transcriptomics data from the three treatments, we found a total of 4,943 unique transcripts that were differentially expressed. CONCLUSIONS We identified transcripts related to pH signaling such as the conserved PAL/RIM pathway, some transcripts related to secondary metabolism and other transcripts that were differentially expressed. Our analysis suggests possible mechanisms involved in pathogenicity in this novel Fusarium species. This is the first report that shows transcriptomic data of this pathogen as well as the first report of genes and proteins involved in their metabolism identifying potential virulence factors.
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Affiliation(s)
- Diana Sánchez-Rangel
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C, 91070 Xalapa, Veracruz Mexico
- Cátedra CONACYT en el Instituto de Ecología A.C, Xalapa, Veracruz Mexico
| | - Eric-Edmundo Hernández-Domínguez
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C, 91070 Xalapa, Veracruz Mexico
- Cátedra CONACYT en el Instituto de Ecología A.C, Xalapa, Veracruz Mexico
| | - Claudia-Anahí Pérez-Torres
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C, 91070 Xalapa, Veracruz Mexico
- Cátedra CONACYT en el Instituto de Ecología A.C, Xalapa, Veracruz Mexico
| | - Randy Ortiz-Castro
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C, 91070 Xalapa, Veracruz Mexico
- Cátedra CONACYT en el Instituto de Ecología A.C, Xalapa, Veracruz Mexico
| | - Emanuel Villafán
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C, 91070 Xalapa, Veracruz Mexico
| | - Benjamín Rodríguez-Haas
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C, 91070 Xalapa, Veracruz Mexico
| | | | - Abel López-Buenfil
- Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria, Unidad Integral de Diagnóstico, Servicios y Constatación, 55740 Tecámac, Estado de México Mexico
| | - Nayeli Carrillo-Ortiz
- Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria, Unidad Integral de Diagnóstico, Servicios y Constatación, 55740 Tecámac, Estado de México Mexico
| | - Lervin Hernández-Ramos
- Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria, Unidad Integral de Diagnóstico, Servicios y Constatación, 55740 Tecámac, Estado de México Mexico
| | - Enrique Ibarra-Laclette
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C, 91070 Xalapa, Veracruz Mexico
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9
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de Souza ÉSDC, do Vale HMM, Pereira Carvalho RDC, Soares WRDO, Miller RNG, Dianese JC. Infection by Uromyces euphorbiae: a trigger for the sporulation of endophytic Colletotrichum truncatum on the common host Euphorbia hirta. Mycol Prog 2017. [DOI: 10.1007/s11557-017-1338-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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10
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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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Li X, Wu Y, Liu Z, Zhang C. The function and transcriptome analysis of a bZIP transcription factor CgAP1 in Colletotrichum gloeosporioides. Microbiol Res 2017; 197:39-48. [PMID: 28219524 DOI: 10.1016/j.micres.2017.01.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 12/10/2016] [Accepted: 01/19/2017] [Indexed: 02/06/2023]
Abstract
Colletotrichum gloeosporioides is an important pathogen of anthracnose, which is able to infect numerous crops in tropical and subtropical regions, causing great economic losses. To investigate the fungal response to host-generated reactive oxygen species (ROS), we cloned and characterized the CgAP1 gene of C. gloeosporioides. CgAP1 encoded a bZIP transcription factor which had a bZIP DNA-binding domain and two cysteine-rich domains structurally and functionally related to Saccharomyces cerevisiae YAP1. Deletion of CgAP1 in C. gloeosporioides resulted in increasing sensitivity to H2O2, changes in cell wall integrity and loss of pathogenicity. To understand the regulatory network of CgAP1, RNA sequencing was used to identify differentially expressed genes in the CgAP1 mutant. It was shown that several genes involved in ROS detoxification and cell wall integrity were affected by CgAP1. Moreover, CgAP1 was also involved in many biological processes especially ribosome, cellular transport and amino acid metabolism. In conclusion, CgAP1 is an important transcription factor involved in oxidative stress, cell wall integrity and pathogenicity in C. gloeosporioides.
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Affiliation(s)
- Xiaoyu Li
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, China
| | - Yateng Wu
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, China
| | - Zhiqiang Liu
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, China.
| | - Chenghui Zhang
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, China
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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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Bi F, Ment D, Luria N, Meng X, Prusky D. Mutation of AREA affects growth, sporulation, nitrogen regulation, and pathogenicity in Colletotrichum gloeosporioides. Fungal Genet Biol 2016; 99:29-39. [PMID: 28027951 DOI: 10.1016/j.fgb.2016.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 12/09/2016] [Accepted: 12/16/2016] [Indexed: 01/09/2023]
Abstract
The GATA transcription factor AreA is a global nitrogen regulator that restricts the utilization of complex and poor nitrogen sources in the presence of good nitrogen sources in microorganisms. In this study, we report the biological function of an AreA homolog (the CgareA gene) in the fruit postharvest pathogen Colletotrichum gloeosporioides. Targeted gene deletion mutants of areA exhibited significant reductions in vegetative growth, increases in conidia production, and slight decreases in conidial germination rates. Quantitative RT-PCR (qRT-PCR) analysis revealed that the expression of AreA was highly induced under nitrogen-limiting conditions. Moreover, compared to wild-type and complemented strains, nitrogen metabolism-related genes were misregulated in ΔareA mutant strains. Pathogenicity assays indicated that the virulence of ΔareA mutant strains were affected by the nitrogen content, but not the carbon content, of fruit hosts. Taken together, our results indicate that CgareA plays a critical role in fungal development, conidia production, regulation of nitrogen metabolism and virulence in Colletotrichum gloeosporioides.
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Affiliation(s)
- Fangcheng Bi
- Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture, Guangzhou 510640, China; Key Laboratory of Tropical and Subtropical Fruit Tree Research, Guangdong Province, Guangzhou 510640, China; Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
| | - Dana Ment
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
| | - Neta Luria
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
| | - Xiangchun Meng
- Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture, Guangzhou 510640, China; Key Laboratory of Tropical and Subtropical Fruit Tree Research, Guangdong Province, Guangzhou 510640, China.
| | - Dov Prusky
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel.
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Bi F, Barad S, Ment D, Luria N, Dubey A, Casado V, Glam N, Mínguez JD, Espeso EA, Fluhr R, Prusky D. Carbon regulation of environmental pH by secreted small molecules that modulate pathogenicity in phytopathogenic fungi. MOLECULAR PLANT PATHOLOGY 2016; 17:1178-95. [PMID: 26666972 PMCID: PMC6638356 DOI: 10.1111/mpp.12355] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 12/08/2015] [Accepted: 12/09/2015] [Indexed: 05/22/2023]
Abstract
Fruit pathogens can contribute to the acidification or alkalinization of the host environment. This capability has been used to divide fungal pathogens into acidifying and/or alkalinizing classes. Here, we show that diverse classes of fungal pathogens-Colletotrichum gloeosporioides, Penicillium expansum, Aspergillus nidulans and Fusarium oxysporum-secrete small pH-affecting molecules. These molecules modify the environmental pH, which dictates acidic or alkaline colonizing strategies, and induce the expression of PACC-dependent genes. We show that, in many organisms, acidification is induced under carbon excess, i.e. 175 mm sucrose (the most abundant sugar in fruits). In contrast, alkalinization occurs under conditions of carbon deprivation, i.e. less than 15 mm sucrose. The carbon source is metabolized by glucose oxidase (gox2) to gluconic acid, contributing to medium acidification, whereas catalysed deamination of non-preferred carbon sources, such as the amino acid glutamate, by glutamate dehydrogenase 2 (gdh2), results in the secretion of ammonia. Functional analyses of Δgdh2 mutants showed reduced alkalinization and pathogenicity during growth under carbon deprivation, but not in high-carbon medium or on fruit rich in sugar, whereas analysis of Δgox2 mutants showed reduced acidification and pathogencity under conditions of excess carbon. The induction pattern of gdh2 was negatively correlated with the expression of the zinc finger global carbon catabolite repressor creA. The present results indicate that differential pH modulation by fruit fungal pathogens is a host-dependent mechanism, affected by host sugar content, that modulates environmental pH to enhance fruit colonization.
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Affiliation(s)
- Fangcheng Bi
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
- Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, and Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture, Guangzhou, 510640, China
| | - Shiri Barad
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Dana Ment
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
| | - Neta Luria
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
| | - Amit Dubey
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
| | - Virginia Casado
- Department of Microbiology and Genetics, CIALE, Universidad de Salamanca, Salamanca, 37007, Spain
| | - Nofar Glam
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Jose Diaz Mínguez
- Department of Microbiology and Genetics, CIALE, Universidad de Salamanca, Salamanca, 37007, Spain
| | - Eduardo A Espeso
- Department of Molecular and Cellular Biology, Centro de Investigaciones Biológicas (C.I.B.), Madrid, 28040, Spain
| | - Robert Fluhr
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Dov Prusky
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel.
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Barad S, Sela N, Kumar D, Kumar-Dubey A, Glam-Matana N, Sherman A, Prusky D. Fungal and host transcriptome analysis of pH-regulated genes during colonization of apple fruits by Penicillium expansum. BMC Genomics 2016; 17:330. [PMID: 27146851 PMCID: PMC4855365 DOI: 10.1186/s12864-016-2665-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 04/26/2016] [Indexed: 11/26/2022] Open
Abstract
Background Penicillium expansum is a destructive phytopathogen that causes decay in deciduous fruits during postharvest handling and storage. During colonization the fungus secretes D-gluconic acid (GLA), which modulates environmental pH and regulates mycotoxin accumulation in colonized tissue. Till now no transcriptomic analysis has addressed the specific contribution of the pathogen's pH regulation to the P. expansum colonization process. For this purpose total RNA from the leading edge of P. expansum-colonized apple tissue of cv. 'Golden Delicious' and from fungal cultures grown under pH 4 or 7 were sequenced and their gene expression patterns were compared. Results We present a large-scale analysis of the transcriptome data of P. expansum and apple response to fungal colonization. The fungal analysis revealed nine different clusters of gene expression patterns that were divided among three major groups in which the colonized tissue showed, respectively: (i) differing transcript expression patterns between mycelial growth at pH 4 and pH 7; (ii) similar transcript expression patterns of mycelial growth at pH 4; and (iii) similar transcript expression patterns of mycelial growth at pH 7. Each group was functionally characterized in order to decipher genes that are important for pH regulation and also for colonization of apple fruits by Penicillium. Furthermore, comparison of gene expression of healthy apple tissue with that of colonized tissue showed that differentially expressed genes revealed up-regulation of the jasmonic acid and mevalonate pathways, and also down-regulation of the glycogen and starch biosynthesis pathways. Conclusions Overall, we identified important genes and functionalities of P. expansum that were controlled by the environmental pH. Differential expression patterns of genes belonging to the same gene family suggest that genes were selectively activated according to their optimal environmental conditions (pH, in vitro or in vivo) to enable the fungus to cope with varying conditions and to make optimal use of available enzymes. Comparison between the activation of the colonized host's gene responses by alkalizing Colletotrichum gloeosporioides and acidifying P. expansum pathogens indicated similar gene response patterns, but stronger responses to P. expansum, suggesting the importance of acidification by P. expansum as a factor in its increased aggressiveness. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2665-7) 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, Bet Dagan, 50250, Israel.,Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Noa Sela
- Department of Plant Pathology and Weed Research, ARO, the Volcani Center, Bet Dagan, 50250, Israel
| | - Dilip Kumar
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, Bet Dagan, 50250, Israel
| | - Amit Kumar-Dubey
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, Bet Dagan, 50250, Israel
| | - Nofar Glam-Matana
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, Bet Dagan, 50250, Israel.,Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Amir Sherman
- Genomics Unit, ARO, the Volcani Center, Bet Dagan, 50250, Israel
| | - Dov Prusky
- Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, Bet Dagan, 50250, Israel.
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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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Ment D, Alkan N, Luria N, Bi FC, Reuveni E, Fluhr R, Prusky D. A Role of AREB in the Regulation of PACC-Dependent Acid-Expressed-Genes and Pathogenicity of Colletotrichum gloeosporioides. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 28:154-66. [PMID: 25317668 DOI: 10.1094/mpmi-09-14-0252-r] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Gene expression regulation by pH in filamentous fungi and yeasts is controlled by the PACC/RIM101 transcription factor. In Colletotrichum gloeosporioides, PACC is known to act as positive regulator of alkaline-expressed genes, and this regulation was shown to contribute to fungal pathogenicity. PACC is also a negative regulator of acid-expressed genes, however; the mechanism of downregulation of acid-expressed genes by PACC and their contribution to C. gloeosporioides pathogenicity is not well understood. RNA sequencing data analysis was employed to demonstrate that PACC transcription factor binding sites (TFBS) are significantly overrepresented in the promoter of PACC-upregulated, alkaline-expressed genes. In contrast, they are not overrepresented in the PACC-downregulated, acid-expressed genes. Instead, acid-expressed genes showed overrepresentation of AREB GATA TFBS in C. gloeosporioides and in homologs of five other ascomycetes genomes. The areB promoter contains PACC TFBS; its transcript was upregulated at pH 7 and repressed in ΔpacC. Furthermore, acid-expressed genes were found to be constitutively upregulated in ΔareB during alkalizing conditions. The areB mutants showed significantly reduced ammonia secretion and pathogenicity on tomato fruit. Present results indicate that PACC activates areB expression, thereby conditionally repressing acid-expressed genes and contributing critically to C. gloeosporioides pathogenicity.
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Alkan N, Friedlander G, Ment D, Prusky D, Fluhr R. Simultaneous transcriptome analysis of Colletotrichum gloeosporioides and tomato fruit pathosystem reveals novel fungal pathogenicity and fruit defense strategies. THE NEW PHYTOLOGIST 2015; 205:801-15. [PMID: 25377514 DOI: 10.1111/nph.13087] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 08/22/2014] [Indexed: 05/20/2023]
Abstract
The fungus Colletotrichum gloeosporioides breaches the fruit cuticle but remains quiescent until fruit ripening signals a switch to necrotrophy, culminating in devastating anthracnose disease. There is a need to understand the distinct fungal arms strategy and the simultaneous fruit response. Transcriptome analysis of fungal-fruit interactions was carried out concurrently in the appressoria, quiescent and necrotrophic stages. Conidia germinating on unripe fruit cuticle showed stage-specific transcription that was accompanied by massive fruit defense responses. The subsequent quiescent stage showed the development of dendritic-like structures and swollen hyphae within the fruit epidermis. The quiescent fungal transcriptome was characterized by activation of chromatin remodeling genes and unsuspected environmental alkalization. Fruit response was portrayed by continued highly integrated massive up-regulation of defense genes. During cuticle infection of green or ripe fruit, fungi recapitulate the same developmental stages but with differing quiescent time spans. The necrotrophic stage showed a dramatic shift in fungal metabolism and up-regulation of pathogenicity factors. Fruit response to necrotrophy showed activation of the salicylic acid pathway, climaxing in cell death. Transcriptome analysis of C. gloeosporioides infection of fruit reveals its distinct stage-specific lifestyle and the concurrent changing fruit response, deepening our perception of the unfolding fungal-fruit arms and defenses race.
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Affiliation(s)
- Noam Alkan
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot, Israel; Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, the Volcani Center, Bet Dagan, 50250, Israel
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Barad S, Horowitz SB, Kobiler I, Sherman A, Prusky D. Accumulation of the mycotoxin patulin in the presence of gluconic acid contributes to pathogenicity of Penicillium expansum. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:66-77. [PMID: 24024763 DOI: 10.1094/mpmi-05-13-0138-r] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Penicillium expansum, the causal agent of blue mold rot, causes severe postharvest fruit maceration through secretion of D-gluconic acid (GLA) and secondary metabolites such as the mycotoxin patulin in colonized tissue. GLA involvement in pathogenicity has been suggested but the mechanism of patulin accumulation and its contribution to P. expansum pathogenicity remain unclear. The roles of GLA and patulin accumulation in P. expansum pathogenicity were studied using i) glucose oxidase GOX2-RNAi mutants exhibiting decreased GOX2 expression, GLA accumulation, and reduced pathogenicity; ii) IDH-RNAi mutants exhibiting downregulation of IDH (the last gene in patulin biosynthesis), reduced patulin accumulation, and no effect on GLA level; and iii) PACC-RNAi mutants exhibiting downregulation of both GOX2 and IDH that reduced GLA and patulin production. Present results indicate that conditions enhancing the decrease in GLA accumulation by GOX2-RNAi and PACC-RNAi mutants, and not low pH, affected patulin accumulation, suggesting GLA production as the driving force for further patulin accumulation. Thus, it is suggested that GLA accumulation may modulate patulin synthesis as a direct precursor under dynamic pH conditions modulating the activation of the transcription factor PACC and the consequent pathogenicity factors, which contribute to host-tissue colonization by P. expansum.
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20
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Fernandez J, Marroquin-Guzman M, Wilson RA. Mechanisms of nutrient acquisition and utilization during fungal infections of leaves. ANNUAL REVIEW OF PHYTOPATHOLOGY 2014; 52:155-74. [PMID: 24848414 DOI: 10.1146/annurev-phyto-102313-050135] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Foliar fungal pathogens challenge global food security, but how they optimize growth and development during infection is understudied. Despite adopting several lifestyles to facilitate nutrient acquisition from colonized cells, little is known about the genetic underpinnings governing pathogen adaption to host-derived nutrients. Homologs of common global and pathway-specific gene regulatory elements are likely to be involved, but their contribution to pathogenicity, and how they are connected to broader genetic networks, is largely unspecified. Here, we focus on carbon and nitrogen metabolism in foliar pathogens and consider what is known, and what is not known, about fungal exploitation of host nutrient and ask how common metabolic regulators have been co-opted to the plant-pathogenic lifestyle as well as how nutrients are utilized to drive infection.
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Affiliation(s)
- Jessie Fernandez
- Department of Plant Pathology, University of Nebraska, Lincoln, Nebraska 68583; , ,
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21
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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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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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The pH signaling transcription factor PacC is required for full virulence in Penicillium digitatum. Appl Microbiol Biotechnol 2013; 97:9087-98. [PMID: 23917633 DOI: 10.1007/s00253-013-5129-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 07/07/2013] [Accepted: 07/12/2013] [Indexed: 01/27/2023]
Abstract
Penicillium digitatum is the most important postharvest pathogen of citrus fruits. Along disease progression, the infected citrus peel tissue is acidified due to the accumulation of organic acids. So far, relatively little is known about the environmental factors that regulate pathogenicity in this fungus. In this study, the role of the pH signaling transcription factor PacC in the pathogenesis of P. digitatum was investigated. We identified the pacC ortholog (PdpacC) in P. digitatum and found that its transcript levels were elevated under alkaline conditions (pH ≥ 7) in vitro, as well as during the infection of citrus fruits in spite of the low pH (about 3.0 to 3.5) of the macerated tissue. Na(+) and pectin also induced the expression of PdpacC. Disruption of PdpacC resulted in impaired mycelial growth under neutral or alkaline pH conditions and on synthetic medium supplemented with pectin as the sole carbon source, and attenuated virulence towards citrus fruits. Introducing the full length of PdpacC into the ΔPdpacC mutant restored all these phenotypes. The expression of the polygalacturonase gene Pdpg2 and pectin lyase gene Pdpnl1 in P. digitatum was upregulated in the wild type strain but not or weakly upregulated in the ΔPdpacC mutant during infection. Disruption of Pdpg2 also resulted in attenuated virulence of P. digitatum towards citrus fruits. Collectively, we conclude that PdPacC plays an important role in pathogenesis of P. digitatum via regulation of the expression of cell wall degradation enzyme genes, such as Pdpg2 and Pdpnl1.
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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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25
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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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Rech GE, Vargas WA, Sukno SA, Thon MR. Identification of positive selection in disease response genes within members of the Poaceae. PLANT SIGNALING & BEHAVIOR 2012; 7:1667-75. [PMID: 23073005 PMCID: PMC3578908 DOI: 10.4161/psb.22362] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Millions of years of coevolution between plants and pathogens can leave footprints on their genomes and genes involved on this interaction are expected to show patterns of positive selection in which novel, beneficial alleles are rapidly fixed within the population. Using information about upregulated genes in maize during Colletotrichum graminicola infection and resources available in the Phytozome database, we looked for evidence of positive selection in the Poaceae lineage, acting on protein coding sequences related with plant defense. We found six genes with evidence of positive selection and another eight with sites showing episodic selection. Some of them have already been described as evolving under positive selection, but others are reported here for the first time including genes encoding isocitrate lyase, dehydrogenases, a multidrug transporter, a protein containing a putative leucine-rich repeat and other proteins with unknown functions. Mapping positively selected residues onto the predicted 3-D structure of proteins showed that most of them are located on the surface, where proteins are in contact with other molecules. We present here a set of Poaceae genes that are likely to be involved in plant defense mechanisms and have evidence of positive selection. These genes are excellent candidates for future functional validation.
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Affiliation(s)
- Gabriel E. Rech
- Centro Hispano-Luso de Investigaciones Agrarias (CIALE); Departamento de Microbiología y Genética; Universidad de Salamanca; Villamayor, Spain
| | - Walter A. Vargas
- Centro Hispano-Luso de Investigaciones Agrarias (CIALE); Departamento de Microbiología y Genética; Universidad de Salamanca; Villamayor, Spain
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