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Achari SR, Edwards J, Mann RC, Kaur JK, Sawbridge T, Summerell BA. Comparative transcriptomic analysis of races 1, 2, 5 and 6 of Fusarium oxysporum f.sp. pisi in a susceptible pea host identifies differential pathogenicity profiles. BMC Genomics 2021; 22:734. [PMID: 34627148 PMCID: PMC8502283 DOI: 10.1186/s12864-021-08033-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 09/23/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND The fungal pathogen Fusarium oxysporum f.sp. pisi (Fop) causes Fusarium wilt in peas. There are four races globally: 1, 2, 5 and 6 and all of these races are present in Australia. Molecular infection mechanisms have been studied in a few other F. oxysporum formae speciales; however, there has been no transcriptomic Fop-pea pathosystem study. RESULTS A transcriptomic study was carried out to understand the molecular pathogenicity differences between the races. Transcriptome analysis at 20 days post-inoculation revealed differences in the differentially expressed genes (DEGs) in the Fop races potentially involved in fungal pathogenicity variations. Most of the DEGs in all the races were engaged in transportation, metabolism, oxidation-reduction, translation, biosynthetic processes, signal transduction, proteolysis, among others. Race 5 expressed the most virulence-associated genes. Most genes encoding for plant cell wall degrading enzymes, CAZymes and effector-like proteins were expressed in race 2. Race 6 expressed the least number of genes at this time point. CONCLUSION Fop races deploy various factors and complex strategies to mitigate host defences to facilitate colonisation. This investigation provides an overview of the putative pathogenicity genes in different Fop races during the necrotrophic stage of infection. These genes need to be functionally characterised to confirm their pathogenicity/virulence roles and the race-specific genes can be further explored for molecular characterisation.
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Affiliation(s)
- Saidi R Achari
- AgriBio, Agriculture Victoria Research, DJPR, Bundoora, Victoria, Australia.
- School of Applied Systems Biology, La Trobe University, Bundoora, Victoria, Australia.
| | - Jacqueline Edwards
- AgriBio, Agriculture Victoria Research, DJPR, Bundoora, Victoria, Australia
- School of Applied Systems Biology, La Trobe University, Bundoora, Victoria, Australia
| | - Ross C Mann
- AgriBio, Agriculture Victoria Research, DJPR, Bundoora, Victoria, Australia
| | - Jatinder K Kaur
- AgriBio, Agriculture Victoria Research, DJPR, Bundoora, Victoria, Australia
| | - Tim Sawbridge
- AgriBio, Agriculture Victoria Research, DJPR, Bundoora, Victoria, Australia
- School of Applied Systems Biology, La Trobe University, Bundoora, Victoria, Australia
| | - Brett A Summerell
- Australian Institute of Botanical Science, Royal Botanic Gardens & Domain Trust, Sydney, NSW, Australia
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He Y, Zhou X, Li J, Li H, Li Y, Nie Y. In Vitro Secretome Analysis Suggests Differential Pathogenic Mechanisms between Fusarium oxysporum f. sp. cubense Race 1 and Race 4. Biomolecules 2021; 11:1353. [PMID: 34572566 PMCID: PMC8466104 DOI: 10.3390/biom11091353] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/07/2021] [Accepted: 09/10/2021] [Indexed: 11/16/2022] Open
Abstract
Banana Fusarium wilt, caused by the fungus pathogen Fusarium oxysporum f. sp. cubense (Foc), is a devastating disease that causes tremendous reductions in banana yield worldwide. Secreted proteins can act as pathogenicity factors and play important roles in the Foc-banana interactions. In this study, a shotgun-based proteomic approach was employed to characterize and compare the secretomes of Foc1 and Foc4 upon banana extract treatment, which detected 1183 Foc1 and 2450 Foc4 proteins. Comprehensive in silico analyses further identified 447 Foc1 and 433 Foc4 proteins in the classical and non-classical secretion pathways, while the remaining proteins might be secreted through currently unknown mechanisms. Further analyses showed that the secretomes of Foc1 and Foc4 are similar in their overall functional characteristics and share largely conserved repertoires of CAZymes and effectors. However, we also identified a number of potentially important pathogenicity factors that are differentially present in Foc1 and Foc4, which may contribute to their different pathogenicity against banana hosts. Furthermore, our quantitative PCR analysis revealed that genes encoding secreted pathogenicity factors differ significantly between Foc1 and Foc4 in their expression regulation in response to banana extract treatment. To our knowledge, this is the first experimental secretome analysis that focused on the pathogenicity mechanism in different Foc races. The results of this study provide useful resources for further exploration of the complicated pathogenicity mechanisms in Foc.
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Affiliation(s)
- Yanqiu He
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China; (Y.H.); (X.Z.); (J.L.); (H.L.)
- College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Xiaofan Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China; (Y.H.); (X.Z.); (J.L.); (H.L.)
- College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Jieling Li
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China; (Y.H.); (X.Z.); (J.L.); (H.L.)
- College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Huaping Li
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China; (Y.H.); (X.Z.); (J.L.); (H.L.)
- College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Yunfeng Li
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China; (Y.H.); (X.Z.); (J.L.); (H.L.)
- College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Yanfang Nie
- College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China
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Tang J, Wu M, Zhang J, Li G, Yang L. Botrytis cinerea G Protein β Subunit Bcgb1 Controls Growth, Development and Virulence by Regulating cAMP Signaling and MAPK Signaling. J Fungi (Basel) 2021; 7:jof7060431. [PMID: 34072395 PMCID: PMC8228952 DOI: 10.3390/jof7060431] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 01/05/2023] Open
Abstract
Botrytis cinerea is a necrotrophic phytopathogenic fungus that causes gray mold disease in many crops. To better understand the role of G protein signaling in the development and virulence of this fungus, the G protein β subunit gene Bcgb1 was knocked out in this study. The ΔBcgb1 mutants showed reduced mycelial growth rate, but increased aerial hyphae and mycelial biomass, lack of conidiation, failed to form sclerotia, increased resistance to cell wall and oxidative stresses, delayed formation of infection cushions, and decreased virulence. Deletion of Bcgb1 resulted in a significant reduction in the expression of several genes involved in cAMP signaling, and caused a notable increase in intracellular cAMP levels, suggesting that G protein β subunit Bcgb1 plays an important role in cAMP signaling. Furthermore, phosphorylation levels of MAP kinases (Bmp1 and Bmp3) were increased in the ΔBcgb1 mutants. Yeast two-hybrid assays showed that Bcgb1 interacts with MAPK (Bmp1 and Bmp3) cascade proteins (BcSte11, BcBck1, BcMkk1, and BcSte50), and the Bmp1-regulated gene Bcgas2 was up-regulated in the ΔBcgb1 mutant. These results indicated that Gβ protein Bcgb1 is involved in the MAPK signaling pathway in B. cinerea. In summary, our results revealed that Gβ protein Bcgb1 controls development and virulence through both the cAMP and MAPK (Bmp1 and Bmp3) signaling pathways in B. cinerea.
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Chang TH, Lin YH, Wan YL, Chen KS, Huang JW, Chang PFL. Degenerated Virulence and Irregular Development of Fusarium oxysporum f. sp. niveum Induced by Successive Subculture. J Fungi (Basel) 2020; 6:jof6040382. [PMID: 33371239 PMCID: PMC7767292 DOI: 10.3390/jof6040382] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/27/2020] [Accepted: 12/12/2020] [Indexed: 11/17/2022] Open
Abstract
Successive cultivation of fungi on artificial media has been reported to cause the sectorization, which leads to degeneration of developmental phenotype, and virulence. Fusarium oxysporum f. sp. niveum (Fon), the causal agent of watermelon Fusarium wilt, forms degenerated sectors after successive cultivation. In the present research, we demonstrated that subculture with aged mycelia increased the incidence of degenerations. To further investigate the differences between the Fon wild type (sporodochial type, ST) and variants (MT: mycelial type and PT: pionnotal type), developmental phenotypes and pathogenicity to watermelon were examined. Results in variants (PT2, PT3, PT11, and MT6) were different from ST with mycelia growth, conidia production and chlamydospore formation. Virulence of degenerated variants on susceptible watermelon Grand Baby (GB) cultivar was determined after inoculation with Fon variants and Fon ST. In root dipping methods, Fon variants showed no significant differences in disease progress compared with ST. Fon variants showed a significant decrease in disease progression compared with ST through infested soil inoculation. The contrasting results of two inoculation methods suggest that the degenerative changes due to repeated successive cultivation may lead to the loss of pathogen virulence-related factors of the early stage of Fon infection process. Therefore, cell wall-degrading enzymes (CWDEs; cellulase, pectinase, and xylanase) activities of different variants were analyzed. All Fon degenerated variants demonstrated significant decreases of CWDEs activities compared with ST. Additionally, transcript levels of 9 virulence-related genes (fmk1, fgb1, pacC, xlnR, pl1, rho1, gas1, wc1, and fow1) were assessed in normal state. The degenerated variants demonstrated a significantly low level of tested virulence-related gene transcripts except for fmk1, xlnR, and fow1. In summary, the degeneration of Fon is triggered with successive subculture through aged mycelia. The degeneration showed significant impacts on virulence to watermelon, which was correlated with the reduction of CWDEs activities and declining expression of a set of virulence-related genes.
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Affiliation(s)
- Tao-Ho Chang
- Department of Plant Pathology, National Chung Hsing University, Taichung City 402204, Taiwan; (T.-H.C.); (Y.-L.W.); (J.-W.H.)
- Innovation and Development Center of Sustainable Agriculture (IDCSA), National Chung Hsing University, Taichung City 402204, Taiwan
| | - Ying-Hong Lin
- Department of Plant Medicine, National Pingtung University of Science and Technology, Pingtung 912301, Taiwan;
- Plant Medicine Teaching Hospital, General Research Service Center, National Pingtung University of Science and Technology, Pingtung 912301, Taiwan
| | - Yu-Ling Wan
- Department of Plant Pathology, National Chung Hsing University, Taichung City 402204, Taiwan; (T.-H.C.); (Y.-L.W.); (J.-W.H.)
| | - Kan-Shu Chen
- Chiayi Experiment Branch, Taiwan Agricultural Research Institute, Chiayi 611002, Taiwan;
| | - Jenn-Wen Huang
- Department of Plant Pathology, National Chung Hsing University, Taichung City 402204, Taiwan; (T.-H.C.); (Y.-L.W.); (J.-W.H.)
- Innovation and Development Center of Sustainable Agriculture (IDCSA), National Chung Hsing University, Taichung City 402204, Taiwan
| | - Pi-Fang Linda Chang
- Department of Plant Pathology, National Chung Hsing University, Taichung City 402204, Taiwan; (T.-H.C.); (Y.-L.W.); (J.-W.H.)
- Innovation and Development Center of Sustainable Agriculture (IDCSA), National Chung Hsing University, Taichung City 402204, Taiwan
- Correspondence: ; Tel.: +886-422840780 (ext. 330)
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Design, synthesis, biological evaluation, molecular docking, DFT calculations and in silico ADME analysis of (benz)imidazole-hydrazone derivatives as promising antioxidant, antifungal, and anti-acetylcholinesterase agents. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128527] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Valle-Maldonado MI, Patiño-Medina JA, Pérez-Arques C, Reyes-Mares NY, Jácome-Galarza IE, Ortíz-Alvarado R, Vellanki S, Ramírez-Díaz MI, Lee SC, Garre V, Meza-Carmen V. The heterotrimeric G-protein beta subunit Gpb1 controls hyphal growth under low oxygen conditions through the protein kinase A pathway and is essential for virulence in the fungus Mucor circinelloides. Cell Microbiol 2020; 22:e13236. [PMID: 32562333 DOI: 10.1111/cmi.13236] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 05/24/2020] [Accepted: 06/09/2020] [Indexed: 12/13/2022]
Abstract
Mucor circinelloides, a dimorphic opportunistic pathogen, expresses three heterotrimeric G-protein beta subunits (Gpb1, Gpb2 and Gpb3). The Gpb1-encoding gene is up-regulated during mycelial growth compared with that in the spore or yeast stage. gpb1 deletion mutation analysis revealed its relevance for an adequate development during the dimorphic transition and for hyphal growth under low oxygen concentrations. Infection assays in mice indicated a phenotype with considerably reduced virulence and tissue invasiveness in the deletion mutants (Δgpb1) and decreased host inflammatory response. This finding could be attributed to the reduced filamentous growth in animal tissues compared with that of the wild-type strain. Mutation in a regulatory subunit of cAMP-dependent protein kinase A (PKA) subunit (PkaR1) resulted in similar phenotypes to Δgpb1. The defects exhibited by the Δgpb1 strain were genetically suppressed by pkaR1 overexpression, indicating that the PKA pathway is controlled by Gpb1 in M. circinelloides. Moreover, during growth under low oxygen levels, cAMP levels were much higher in the Δgpb1 than in the wild-type strain, but similar to those in the ΔpkaR1 strain. These findings reveal that M. circinelloides possesses a signal transduction pathway through which the Gpb1 heterotrimeric G subunit and PkaR1 control mycelial growth in response to low oxygen levels.
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Affiliation(s)
- Marco Iván Valle-Maldonado
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Mexico
| | - José Alberto Patiño-Medina
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Mexico
| | - Carlos Pérez-Arques
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - Nancy Yadira Reyes-Mares
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Mexico
| | | | - Rafael Ortíz-Alvarado
- Facultad de Quimico Farmacobiología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mexico
| | - Sandeep Vellanki
- South Texas Center for Emerging Infectious Diseases (STCEID), Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, USA
| | - Martha Isela Ramírez-Díaz
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Mexico
| | - Soo Chan Lee
- South Texas Center for Emerging Infectious Diseases (STCEID), Department of Biology, The University of Texas at San Antonio, San Antonio, Texas, USA
| | - Victoriano Garre
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - Víctor Meza-Carmen
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, Mexico
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Gabriel AF, Costa MC, Enguita FJ, Leitão AL. Si vis pacem para bellum: A prospective in silico analysis of miRNA-based plant defenses against fungal infections. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 288:110241. [PMID: 31521215 DOI: 10.1016/j.plantsci.2019.110241] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/31/2019] [Accepted: 08/25/2019] [Indexed: 06/10/2023]
Abstract
Fungal pathogens are an important threat for plant crops, being responsible for important reductions of production yields and a consequent economic impact. Among the molecular mediators of fungal infections of plant crops, non-coding RNAs (ncRNAs) have been described as relevant players either in the plant immune responses and mechanism of defense or in the colonization of plant tissues by fungi. Acting as a mechanism of defense, some plant small ncRNAs such as miRNAs and tasiRNAs can be secreted by cells and directed to target the transcriptome of pathogenic fungi, triggering an RNAi-like interference mechanism able to silence the expression of specific fungal genes. The detailed knowledge of this mechanism of defense against fungal pathogens could open new possibilities for the protection of human important crops. To infer putative functional relationships mediated by ncRNA communication, we performed a prospective analysis to determine potential plant miRNAs able to target the genome of fungal pathogens, which resulted in the description of enriched specific plant miRNA families and their putative fungal targets that could be further studied in the context of plant-fungi interactions. The expression profile of specific members of the enriched miRNAs families showed an infection-dependent behavior in laboratory models of infection. Plant miRNAs showed sequence complementarity with coding genes of their cognate fungal pathogens. Plant miRNAs could potentially target fungal genes belonging to functional families related to stress response, membrane architecture, vacuolar transport, membrane traffic, and anabolic processes. Families of specific infection-responsive miRNAs are included in the putative plant defense mechanism.
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Affiliation(s)
- André F Gabriel
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028, Lisboa, Portugal
| | - Marina C Costa
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028, Lisboa, Portugal
| | - Francisco J Enguita
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028, Lisboa, Portugal.
| | - Ana Lúcia Leitão
- Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, 2829-516, Caparica, Portugal; MEtRICs, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, Caparica, 2829-516, Portugal.
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Sharma L, Marques G. Fusarium, an Entomopathogen-A Myth or Reality? Pathogens 2018; 7:E93. [PMID: 30487454 PMCID: PMC6314043 DOI: 10.3390/pathogens7040093] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 11/24/2018] [Accepted: 11/26/2018] [Indexed: 12/16/2022] Open
Abstract
The Fusarium species has diverse ecological functions ranging from saprophytes, endophytes, and animal and plant pathogens. Occasionally, they are isolated from dead and alive insects. However, research on fusaria-insect associations is very limited as fusaria are generalized as opportunistic insect-pathogens. Additionally, their phytopathogenicity raises concerns in their use as commercial biopesticides. Insect biocontrol potential of Fusarium is favored by their excellent soil survivability as saprophytes, and sometimes, insect-pathogenic strains do not exhibit phytopathogenicity. In addition, a small group of fusaria, those belonging to the Fusarium solani species complex, act as insect mutualists assisting in host growth and fecundity. In this review, we summarize mutualism and pathogenicity among fusaria and insects. Furthermore, we assert on Fusarium entomopathogenicity by analyzing previous studies clearly demonstrating their natural insect-pathogenicity in fields, and their presence in soils. We also review the presence and/or production of a well-known insecticidal metabolite beauvericin by different Fusarium species. Lastly, some proof-of-concept studies are also summarized, which demonstrate the histological as well as immunological changes that a larva undergoes during Fusarium oxysporum pathogenesis. These reports highlight the insecticidal properties of some Fusarium spp., and emphasize the need of robust techniques, which can distinguish phytopathogenic, mutualistic and entomopathogenic fusaria.
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Affiliation(s)
- Lav Sharma
- CITAB-Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000⁻801 Vila Real, Portugal.
| | - Guilhermina Marques
- CITAB-Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000⁻801 Vila Real, Portugal.
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Segorbe D, Di Pietro A, Pérez‐Nadales E, Turrà D. Three Fusarium oxysporum mitogen-activated protein kinases (MAPKs) have distinct and complementary roles in stress adaptation and cross-kingdom pathogenicity. MOLECULAR PLANT PATHOLOGY 2017; 18:912-924. [PMID: 27301316 PMCID: PMC6638227 DOI: 10.1111/mpp.12446] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Revised: 06/09/2016] [Accepted: 06/10/2016] [Indexed: 05/19/2023]
Abstract
Mitogen-activated protein kinase (MAPK) cascades mediate cellular responses to environmental signals. Previous studies in the fungal pathogen Fusarium oxysporum have revealed a crucial role of Fmk1, the MAPK orthologous to Saccharomyces cerevisiae Fus3/Kss1, in vegetative hyphal fusion and plant infection. Here, we genetically dissected the individual and combined contributions of the three MAPKs Fmk1, Mpk1 and Hog1 in the regulation of development, stress response and virulence of F. oxysporum on plant and animal hosts. Mutants lacking Fmk1 or Mpk1 were affected in reactive oxygen species (ROS) homeostasis and impaired in hyphal fusion and aggregation. Loss of Mpk1 also led to increased sensitivity to cell wall and heat stress, which was exacerbated by simultaneous inactivation of Fmk1, suggesting that both MAPKs contribute to cellular adaptation to high temperature, a prerequisite for mammalian pathogens. Deletion of Hog1 caused increased sensitivity to hyperosmotic stress and resulted in partial rescue of the restricted colony growth phenotype of the mpk1Δ mutant. Infection assays on tomato plants and the invertebrate animal host Galleria mellonella revealed distinct and additive contributions of the different MAPKs to virulence. Our results indicate that positive and negative cross-talk between the three MAPK pathways regulates stress adaptation, development and virulence in the cross-kingdom pathogen F. oxysporum.
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Affiliation(s)
- David Segorbe
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3Universidad de Córdoba14071CórdobaSpain
- Present address:
Department of Genetics and Microbiology, Faculty of ScienceCharles UniversityPragueCzech Republic
| | - Antonio Di Pietro
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3Universidad de Córdoba14071CórdobaSpain
| | - Elena Pérez‐Nadales
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3Universidad de Córdoba14071CórdobaSpain
- Present address:
Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)Hospital Universitario Reina Sofía, Universidad deCórdobaEspaña
| | - David Turrà
- Departamento de Genética, Campus de Excelencia Internacional Agroalimentario ceiA3Universidad de Córdoba14071CórdobaSpain
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Harris SD. Branching of fungal hyphae: regulation, mechanisms and comparison with other branching systems. Mycologia 2017; 100:823-32. [DOI: 10.3852/08-177] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Steven D. Harris
- Department of Plant Pathology and Center for Plant Science Innovation, University of Nebraska, Lincoln, Nebraska 68588
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Lin R, He L, He J, Qin P, Wang Y, Deng Q, Yang X, Li S, Wang S, Wang W, Liu H, Li P, Zheng A. Comprehensive analysis of microRNA-Seq and target mRNAs of rice sheath blight pathogen provides new insights into pathogenic regulatory mechanisms. DNA Res 2016; 23:415-425. [PMID: 27374612 PMCID: PMC5066168 DOI: 10.1093/dnares/dsw024] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 05/12/2016] [Indexed: 02/03/2023] Open
Abstract
MicroRNAs (miRNAs) are ∼22 nucleotide non-coding RNAs that regulate gene expression by targeting mRNAs for degradation or inhibiting protein translation. To investigate whether miRNAs regulate the pathogenesis in necrotrophic fungus Rhizoctonia solani AG1 IA, which causes significant yield loss in main economically important crops, and to determine the regulatory mechanism occurring during pathogenesis, we constructed hyphal small RNA libraries from six different infection periods of the rice leaf. Through sequencing and analysis, 177 miRNA-like small RNAs (milRNAs) were identified, including 15 candidate pathogenic novel milRNAs predicted by functional annotations of their target mRNAs and expression patterns of milRNAs and mRNAs during infection. Reverse transcription-quantitative polymerase chain reaction results for randomly selected milRNAs demonstrated that our novel comprehensive predictions had a high level of accuracy. In our predicted pathogenic protein-protein interaction network of R. solani, we added the related regulatory milRNAs of these core coding genes into the network, and could understand the relationships among these regulatory factors more clearly at the systems level. Furthermore, the putative pathogenic Rhi-milR-16, which negatively regulates target gene expression, was experimentally validated to have regulatory functions by a dual-luciferase reporter assay. Additionally, 23 candidate rice miRNAs that may involve in plant immunity against R. solani were discovered. This first study on novel pathogenic milRNAs of R. solani AG1 IA and the recognition of target genes involved in pathogenicity, as well as rice miRNAs, participated in defence against R. solani could provide new insights into revealing the pathogenic mechanisms of the severe rice sheath blight disease.
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Affiliation(s)
- Runmao Lin
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China
| | - Liye He
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China
| | - Jiayu He
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China
| | - Peigang Qin
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China
| | - Yanran Wang
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China
| | - Qiming Deng
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China.,Key Laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu 611130, China.,Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Ya'an 625014, China
| | - Xiaoting Yang
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China
| | - Shuangcheng Li
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China.,Key Laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu 611130, China
| | - Shiquan Wang
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China.,Key Laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu 611130, China
| | - Wenming Wang
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China.,Key Laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu 611130, China
| | - Huainian Liu
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China
| | - Ping Li
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China.,Key Laboratory of Southwest Crop Gene Resource and Genetic Improvement of Ministry of Education, Sichuan Agricultural University, Ya'an 625014, China
| | - Aiping Zheng
- Rice Research Institute of Sichuan Agricultural University, Chengdu 611130, China.,Key Laboratory of Sichuan Crop Major Disease, Sichuan Agricultural University, Chengdu 611130, China
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Miguel-Rojas C, Hera C. The F-box protein Fbp1 functions in the invasive growth and cell wall integrity mitogen-activated protein kinase (MAPK) pathways in Fusarium oxysporum. MOLECULAR PLANT PATHOLOGY 2016; 17:55-64. [PMID: 25808603 PMCID: PMC6638410 DOI: 10.1111/mpp.12259] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
F-box proteins determine substrate specificity of the ubiquitin-proteasome system. Previous work has demonstrated that the F-box protein Fbp1, a component of the SCF(Fbp1) E3 ligase complex, is essential for invasive growth and virulence of the fungal plant pathogen Fusarium oxysporum. Here, we show that, in addition to invasive growth, Fbp1 also contributes to vegetative hyphal fusion and fungal adhesion to tomato roots. All of these functions have been shown previously to require the mitogen-activated protein kinase (MAPK) Fmk1. We found that Fbp1 is required for full phosphorylation of Fmk1, indicating that Fbp1 regulates virulence and invasive growth via the Fmk1 pathway. Moreover, the Δfbp1 mutant is hypersensitive to sodium dodecylsulfate (SDS) and calcofluor white (CFW) and shows reduced phosphorylation levels of the cell wall integrity MAPK Mpk1 after SDS treatment. Collectively, these results suggest that Fbp1 contributes to both the invasive growth and cell wall integrity MAPK pathways of F. oxysporum.
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Affiliation(s)
- Cristina Miguel-Rojas
- Departamento de Genética, Facultad de Ciencias, Universidad de Córdoba, 14071, Córdoba, Spain
- Campus de Excelencia Internacional Agroalimentario ceiA3, 14071, Córdoba, Spain
| | - Concepcion Hera
- Departamento de Genética, Facultad de Ciencias, Universidad de Córdoba, 14071, Córdoba, Spain
- Campus de Excelencia Internacional Agroalimentario ceiA3, 14071, Córdoba, Spain
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Perez-Nadales E, Di Pietro A. The transmembrane protein Sho1 cooperates with the mucin Msb2 to regulate invasive growth and plant infection in Fusarium oxysporum. MOLECULAR PLANT PATHOLOGY 2015; 16:593-603. [PMID: 25382187 PMCID: PMC6638380 DOI: 10.1111/mpp.12217] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In the vascular wilt pathogen Fusarium oxysporum, the mitogen-activated protein kinase (MAPK) Fmk1 is essential for plant infection. The mucin-like membrane protein Msb2 regulates a subset of Fmk1-dependent functions. Here, we examined the role of the tetraspan transmembrane protein Sho1 as an additional regulator of the Fmk1 pathway and determined its genetic interaction with Msb2. Targeted Δsho1 mutants were generated in wild-type and Δmsb2 backgrounds to test possible interactions between the two genes. The mutants were examined for hyphal growth under different stress conditions, phosphorylation of the MAPK Fmk1 and an array of Fmk1-dependent virulence functions. Similar to Msb2, Sho1 was required for the activation of Fmk1 phosphorylation, as well as Fmk1-dependent gene expression and invasive growth functions, including extracellular pectinolytic activity, cellophane penetration, plant tissue colonization and virulence on tomato plants. Δsho1 mutants were hypersensitive to the cell wall-perturbing compound Calcofluor White, and this phenotype was exacerbated in the Δmsb2 Δsho1 double mutant. These results highlight that Sho1 and Msb2 have partially overlapping functions upstream of the Fmk1 MAPK cascade, to promote invasive growth and plant infection, as well as cell wall integrity, in F. oxysporum.
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Affiliation(s)
- Elena Perez-Nadales
- Departamento de Genética and Campus de Excelencia Agroalimentario (ceiA3), Universidad de Córdoba, 14071, Córdoba, Spain
| | - Antonio Di Pietro
- Departamento de Genética and Campus de Excelencia Agroalimentario (ceiA3), Universidad de Córdoba, 14071, Córdoba, Spain
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Lei D, Lin R, Yin C, Li P, Zheng A. Global protein-protein interaction network of rice sheath blight pathogen. J Proteome Res 2014; 13:3277-93. [PMID: 24894516 DOI: 10.1021/pr500069r] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Rhizoctonia solani is the major pathogenic fungi of rice sheath blight. It is responsible for the most serious disease of rice (Oryza sativa L.) and causes significant yield losses in rice-growing countries. Identifying the protein-protein interaction (PPI) maps of R. solani can provide insights into the potential pathogenic mechanisms and assign putative functions to unknown genes. Here, we exploited a PPI map of R. solani anastomosis group 1 IA (AG-1 IA) based on the interolog and domain-domain interaction methods. We constructed a core subset of high-confidence protein networks consisting of 6705 interactions among 1773 proteins. The high quality of the network was revealed by comprehensive methods, including yeast two-hybrid experiments. Pathogenic interaction subnetwork, secreted proteins subnetwork, and mitogen-activated protein kinase (MAPK) cascade subnetwork and their interacting partners were constructed and analyzed. Moreover, to exactly predict the pathogenic factors, the expression levels of the interaction proteins were investigated by analyzing RNA sequences that consisted of samples from the entire infection progress. The PPIs offer an exceptionally rich source of data that can be used to understand the gene functions and biological processes of this serious disease at the system level.
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Affiliation(s)
- Ding Lei
- Rice Research Institute of Sichuan Agricultural University , Chengdu 611130, China
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15
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Cloning and functional analysis of the Gβ gene Mgb1 and the Gγ gene Mgg1 in Monascus ruber. J Microbiol 2014; 52:35-43. [DOI: 10.1007/s12275-014-3072-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 07/18/2013] [Accepted: 07/31/2013] [Indexed: 11/26/2022]
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16
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Kaneko I, Iyama-Kadono M, Togashi-Nishigata K, Yamaguchi I, Teraoka T, Arie T. Heterotrimeric G protein β subunit GPB1 and MAP kinase MPK1 regulate hyphal growth and female fertility in Fusarium sacchari. MYCOSCIENCE 2013. [DOI: 10.1016/j.myc.2012.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Fellers JP, Soltani BM, Bruce M, Linning R, Cuomo CA, Szabo LJ, Bakkeren G. Conserved loci of leaf and stem rust fungi of wheat share synteny interrupted by lineage-specific influx of repeat elements. BMC Genomics 2013; 14:60. [PMID: 23356831 PMCID: PMC3579696 DOI: 10.1186/1471-2164-14-60] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 01/11/2013] [Indexed: 12/26/2022] Open
Abstract
Background Wheat leaf rust (Puccinia triticina Eriks; Pt) and stem rust fungi (P. graminis f.sp. tritici; Pgt) are significant economic pathogens having similar host ranges and life cycles, but different alternate hosts. The Pt genome, currently estimated at 135 Mb, is significantly larger than Pgt, at 88 Mb, but the reason for the expansion is unknown. Three genomic loci of Pt conserved proteins were characterized to gain insight into gene content, genome complexity and expansion. Results A bacterial artificial chromosome (BAC) library was made from P. triticina race 1, BBBD and probed with Pt homologs of genes encoding two predicted Pgt secreted effectors and a DNA marker mapping to a region of avirulence. Three BACs, 103 Kb, 112 Kb, and 166 Kb, were sequenced, assembled, and open reading frames were identified. Orthologous genes were identified in Pgt and local conservation of gene order (microsynteny) was observed. Pairwise protein identities ranged from 26 to 99%. One Pt BAC, containing a RAD18 ortholog, shares syntenic regions with two Pgt scaffolds, which could represent both haplotypes of Pgt. Gene sequence is diverged between the species as well as within the two haplotypes. In all three BAC clones, gene order is locally conserved, however, gene shuffling has occurred relative to Pgt. These regions are further diverged by differing insertion loci of LTR-retrotransposon, Gypsy, Copia, Mutator, and Harbinger mobile elements. Uncharacterized Pt open reading frames were also found; these proteins are high in lysine and similar to multiple proteins in Pgt. Conclusions The three Pt loci are conserved in gene order, with a range of gene sequence divergence. Conservation of predicted haustoria expressed secreted protein genes between Pt and Pgt is extended to the more distant poplar rust, Melampsora larici-populina. The loci also reveal that genome expansion in Pt is in part due to higher occurrence of repeat-elements in this species.
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Affiliation(s)
- John P Fellers
- USDA-ARS, Hard Winter Wheat Genetics Research Unit, Department of Plant Pathology, Manhattan, KS 66506, USA.
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Horevaj P, Bluhm BH. BDM1, a phosducin-like gene of Fusarium graminearum, is involved in virulence during infection of wheat and maize. MOLECULAR PLANT PATHOLOGY 2012; 13:431-444. [PMID: 22044756 PMCID: PMC6638705 DOI: 10.1111/j.1364-3703.2011.00758.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Fusarium graminearum is a common pathogen of wheat and maize throughout the world. Despite recent advances in the elucidation of the genetic basis of virulence, significant gaps in the regulatory network underlying pathogenesis remain to be filled. In particular, little is known at the molecular level about the overlap among mechanisms of pathogenicity on maize and wheat. G-protein signalling has been implicated in pathogenesis in F. graminearum, although the underlying mechanisms are not fully understood. In this study, we investigated the involvement of a putative phosducin-like gene (BDM1) in growth, development and pathogenesis in F. graminearum. Targeted deletion of BDM1 revealed roles in sexual and asexual sporulation, germ tube development, hyphal branching and mycelial morphology. During pathogenesis, BDM1 is required for wild-type levels of colonization of maize silk tissue and stalks, but is dispensable for the colonization of kernels. The deletion of BDM1 also reduced the virulence of F. graminearum during the infection of wheat seedlings and heads, resulting in a significant reduction in fungal biomass and a delayed spread of visual symptom expression (i.e. bleaching in heads). Furthermore, BDM1 is required for wild-type levels of deoxynivalenol biosynthesis during the infection of wheat heads and maize silks. In summation, BDM1 is one of the few genes characterized to date in F. graminearum involved in virulence during infection of both maize and wheat. Thus, the functional characterization of BDM1 has established a new regulatory link between pathogenesis in maize and wheat, and provides a genetic resource through which the regulatory networks underlying virulence in F. graminearum can be further elucidated.
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Affiliation(s)
- Peter Horevaj
- Department of Plant Pathology, University of Arkansas Division of Agriculture, Fayetteville, AR 72701, USA
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Prados-Rosales RC, Roldán-Rodríguez R, Serena C, López-Berges MS, Guarro J, Martínez-del-Pozo Á, Di Pietro A. A PR-1-like protein of Fusarium oxysporum functions in virulence on mammalian hosts. J Biol Chem 2012; 287:21970-9. [PMID: 22553200 DOI: 10.1074/jbc.m112.364034] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The pathogenesis-related PR-1-like protein family comprises secreted proteins from the animal, plant, and fungal kingdoms whose biological function remains poorly understood. Here we have characterized a PR-1-like protein, Fpr1, from Fusarium oxysporum, an ubiquitous fungal pathogen that causes vascular wilt disease on a wide range of plant species and can produce life-threatening infections in immunocompromised humans. Fpr1 is secreted and proteolytically processed by the fungus. The fpr1 gene is required for virulence in a disseminated immunodepressed mouse model, and its function depends on the integrity of the proposed active site of PR-1-like proteins. Fpr1 belongs to a gene family that has expanded in plant pathogenic Sordariomycetes. These results suggest that secreted PR-1-like proteins play important roles in fungal pathogenicity.
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Affiliation(s)
- Rafael C Prados-Rosales
- Departamento de Genetica, Facultad de Ciencias and Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Cordoba, 14071 Cordoba, Spain
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20
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Tzima AK, Paplomatas EJ, Tsitsigiannis DI, Kang S. The G protein β subunit controls virulence and multiple growth- and development-related traits in Verticillium dahliae. Fungal Genet Biol 2012; 49:271-83. [PMID: 22387367 DOI: 10.1016/j.fgb.2012.02.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 02/10/2012] [Accepted: 02/13/2012] [Indexed: 11/26/2022]
Abstract
To gain insight into the role of G protein-mediated signaling in virulence and development of the soilborne, wilt causing fungus Verticillium dahliae, the G protein β subunit gene (named as VGB) was disrupted in tomato race 1 strain of V. dahliae. A resulting mutant strain, 70ΔGb15, displayed drastic reduction in virulence, increased microsclerotia formation and conidiation, and decreased ethylene production compared to the corresponding wild type (wt) strain 70wt-r1. Moreover, 70ΔGb15 exhibited an elongated rather than radial growth pattern on agar media. A transformant of 70ΔGb15 (named as 70ΔGbPKAC1) that carries an extra copy of VdPKAC1, a V. dahliae gene encoding the catalytic subunit of the cAMP-dependent protein kinase A, exhibited wt growth pattern and conidiation, was unable to form microsclerotia, produced high amounts of ethylene, and exhibited virulence between that of 70ΔGb15 and 70wt-r1 on tomato plants. Phenotypical changes observed in 70ΔGb15 and 70ΔGbPKAC1 correlated with transcriptional changes in several genes involved in signaling (MAP kinase VMK1) and development (hydrophobin VDH1 and ACC synthase ACS1) of V. dahliae. Results from the present work suggest a linkage between VGB and VdPKAC1 signaling pathways in regulating virulence, hormone production and development in V. dahliae.
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Affiliation(s)
- Aliki K Tzima
- Laboratory of Plant Pathology, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece.
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21
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Galleria mellonella as model host for the trans-kingdom pathogen Fusarium oxysporum. Fungal Genet Biol 2011; 48:1124-9. [PMID: 21907298 DOI: 10.1016/j.fgb.2011.08.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2011] [Accepted: 08/24/2011] [Indexed: 11/23/2022]
Abstract
Fusarium oxysporum, the causal agent of vascular wilt disease, affects a wide range of plant species and can produce disseminated infections in humans. F. oxysporum f. sp. lycopersici isolate FGSC 9935 causes disease both on tomato plants and immunodepressed mice, making it an ideal model for the comparative analysis of fungal virulence on plant and animal hosts. Here we tested the ability of FGSC 9935 to cause disease in the greater wax moth Galleria mellonella, an invertebrate model host that is widely used for the study of microbial human pathogens. Injection of living but not of heat-killed microconidia into the hemocoel of G. mellonella larvae resulted in dose-dependent killing both at 30°C and at 37°C. Fluorescence microscopy of larvae inoculated with a F. oxysporum transformant expressing GFP revealed hyphal proliferation within the hemocoel, interaction with G. mellonella hemocytes, and colonization of the killed insects by the fungus. Fungal gene knockout mutants previously tested in the tomato and immunodepressed mouse systems displayed a good correlation in virulence between the Galleria and the mouse model. Thus, Galleria represents a useful non-vertebrate infection model for studying virulence mechanisms of F. oxysporum on animal hosts.
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22
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Rispail N, Di Pietro A. The homeodomain transcription factor Ste12: Connecting fungal MAPK signalling to plant pathogenicity. Commun Integr Biol 2011; 3:327-32. [PMID: 20798817 DOI: 10.4161/cib.3.4.11908] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Accepted: 03/25/2010] [Indexed: 11/19/2022] Open
Abstract
A conserved mitogen-activated protein kinase (MAPK) cascade orthologous to the mating/filamentation MAPK pathway in yeast is required for fungal pathogenicity on plants. One of the key targets of this signaling pathway is the homeodomain transcription factor Ste12. Mutational analysis of ste12 orthologues in a variety of plant pathogenic fungi suggests that Ste12 functions as a master regulator of invasive growth. In this mini-review we highlight recent progress in understanding the role of Ste12 in filamentous fungi and discuss future challenges of unravelling the mechanisms by which Ste12 controls fungal virulence downstream of the Pathogenicity MAPK cascade.
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Affiliation(s)
- Nicolas Rispail
- Departamento de Gen'etica; Universidad de C'ordoba; Campus de Rabanales Edif. C5; C'ordoba, Spain
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23
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Kim HS, Park SY, Lee S, Adams EL, Czymmek K, Kang S. Loss of cAMP-dependent protein kinase A affects multiple traits important for root pathogenesis by Fusarium oxysporum. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2011; 24:719-732. [PMID: 21261464 DOI: 10.1094/mpmi-11-10-0267] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The soilborne fungal pathogen Fusarium oxysporum causes vascular wilt and root rot diseases in many plant species. We investigated the role of cyclic AMP-dependent protein kinase A of F. oxysporum (FoCPKA) in growth, morphology, and root attachment, penetration, and pathogenesis in Arabidopsis thaliana. Affinity of spore attachment to root surfaces of A. thaliana, observed microscopically and measured by atomic force microscopy, was reduced by a loss-of-function mutation in the gene encoding the catalytic subunit of FoCPKA. The resulting mutants also failed to penetrate into the vascular system of A. thaliana roots and lost virulence. Even when the mutants managed to enter the vascular system via physically wounded roots, the degree of vascular colonization was significantly lower than that of the corresponding wild-type strain O-685 and no noticeable disease symptoms were observed. The mutants also had reduced vegetative growth and spore production, and their hyphal growth patterns were distinct from those of O-685. Coinoculation of O-685 with an focpkA mutant or a strain nonpathogenic to A. thaliana significantly reduced disease severity and the degree of root colonization by O-685. Several experimental tools useful for studying mechanisms of fungal root pathogenesis are also introduced.
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Affiliation(s)
- Hye-Seon Kim
- Department of Plant Pathology, The Pennsylvania State University, University Park, PA, USA
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Pérez-Nadales E, Di Pietro A. The membrane mucin Msb2 regulates invasive growth and plant infection in Fusarium oxysporum. THE PLANT CELL 2011; 23:1171-85. [PMID: 21441438 PMCID: PMC3082261 DOI: 10.1105/tpc.110.075093] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 02/18/2011] [Accepted: 03/08/2011] [Indexed: 05/20/2023]
Abstract
Fungal pathogenicity in plants requires a conserved mitogen-activated protein kinase (MAPK) cascade homologous to the yeast filamentous growth pathway. How this signaling cascade is activated during infection remains poorly understood. In the soil-borne vascular wilt fungus Fusarium oxysporum, the orthologous MAPK Fmk1 (Fusarium MAPK1) is essential for root penetration and pathogenicity in tomato (Solanum lycopersicum) plants. Here, we show that Msb2, a highly glycosylated transmembrane protein, is required for surface-induced phosphorylation of Fmk1 and contributes to a subset of Fmk1-regulated functions related to invasive growth and virulence. Mutants lacking Msb2 share characteristic phenotypes with the Δfmk1 mutant, including defects in cellophane invasion, penetration of the root surface, and induction of vascular wilt symptoms in tomato plants. In contrast with Δfmk1, Δmsb2 mutants were hypersensitive to cell wall targeting compounds, a phenotype that was exacerbated in a Δmsb2 Δfmk1 double mutant. These results suggest that the membrane mucin Msb2 promotes invasive growth and plant infection upstream of Fmk1 while contributing to cell integrity through a distinct pathway.
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Proteomics of plant pathogenic fungi. J Biomed Biotechnol 2010; 2010:932527. [PMID: 20589070 PMCID: PMC2878683 DOI: 10.1155/2010/932527] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 02/03/2010] [Accepted: 03/01/2010] [Indexed: 12/15/2022] Open
Abstract
Plant pathogenic fungi cause important yield losses in crops. In order to develop efficient and environmental friendly crop protection strategies, molecular studies of the fungal biological cycle, virulence factors, and interaction with its host are necessary. For that reason, several approaches have been performed using both classical genetic, cell biology, and biochemistry and the modern, holistic, and high-throughput, omic techniques. This work briefly overviews the tools available for studying Plant Pathogenic Fungi and is amply focused on MS-based Proteomics analysis, based on original papers published up to December 2009. At a methodological level, different steps in a proteomic workflow experiment are discussed. Separate sections are devoted to fungal descriptive (intracellular, subcellular, extracellular) and differential expression proteomics and interactomics. From the work published we can conclude that Proteomics, in combination with other techniques, constitutes a powerful tool for providing important information about pathogenicity and virulence factors, thus opening up new possibilities for crop disease diagnosis and crop protection.
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Rispail N, Di Pietro A. The two-component histidine kinase Fhk1 controls stress adaptation and virulence of Fusarium oxysporum. MOLECULAR PLANT PATHOLOGY 2010; 11:395-407. [PMID: 20447287 PMCID: PMC6640475 DOI: 10.1111/j.1364-3703.2010.00612.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Fungal histidine kinases (HKs) have been implicated in different processes, such as the osmostress response, hyphal development, sensitivity to fungicides and virulence. Members of HK class III are known to signal through the HOG mitogen-activated protein kinase (MAPK), but possible interactions with other MAPKs have not been explored. In this study, we have characterized fhk1, encoding a putative class III HK from the soil-borne vascular wilt pathogen Fusarium oxysporum. Inactivation of fhk1 resulted in resistance to phenylpyrrole and dicarboximide fungicides, as well as increased sensitivity to hyperosmotic stress and menadione-induced oxidative stress. The osmosensitivity of Delta fhk1 mutants was associated with a striking and previously unreported change in colony morphology. The Delta fhk1 strains showed a significant decrease in virulence on tomato plants. Epistatic analysis between Fhk1 and the Fmk1 MAPK cascade indicated that Fhk1 does not function upstream of Fmk1, but that the two pathways may interact to control the response to menadione-induced oxidative stress.
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Affiliation(s)
- Nicolas Rispail
- Departamento de Genética, Universidad de Córdoba, Campus de Rabanales Edificio Gregor Mendel C5, 14071 Córdoba, Spain.
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Rispail N, Di Pietro A. Fusarium oxysporum Ste12 controls invasive growth and virulence downstream of the Fmk1 MAPK cascade. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2009; 22:830-9. [PMID: 19522565 DOI: 10.1094/mpmi-22-7-0830] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A conserved mitogen-activated protein kinase (MAPK) cascade homologous to the yeast Fus3/Kss1 mating/filamentation pathway regulates virulence in fungal plant pathogens. In the soilborne fungus Fusarium oxysporum, the MAPK Fmk1 is required for infection and development of vascular wilt disease on tomato plants. Knockout mutants lacking Fmk1 are deficient in multiple virulence-related functions, including root adhesion and penetration, invasive growth, secretion of pectinolytic enzymes, and vegetative hyphal fusion. The transcription factors mediating these different outputs downstream of the MAPK cascade are currently unknown. In this study, we have analyzed the role of ste12 which encodes an orthologue of the yeast homeodomain transcription factor Ste12p. F. oxysporum mutants lacking the ste12 gene were impaired in invasive growth on tomato and apple fruit tissue and in penetration of cellophane membranes. However, ste12 was not required for adhesion to tomato roots, secretion of pectinolytic enzymes, and vegetative hyphal fusion, suggesting that these Fmk1-dependent functions are mediated by other downstream MAPK targets. The Delta ste12 strains displayed dramatically reduced virulence on tomato plants, similar to the Delta fmk1 mutant. These results indicate that invasive growth is the major virulence function controlled by the Fmk1 MAPK cascade and depends critically on the transcription factor Ste12.
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Affiliation(s)
- Nicolas Rispail
- Departamento de Genética, Universidad de Córdoba, Campus de Rabanales Edificio Gregor Mendel, Córdoba, Spain
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28
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G(alpha) and Gbeta proteins regulate the cyclic AMP pathway that is required for development and pathogenicity of the phytopathogen Mycosphaerella graminicola. EUKARYOTIC CELL 2009; 8:1001-13. [PMID: 19411619 DOI: 10.1128/ec.00258-08] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We identified and functionally characterized genes encoding three Galpha proteins and one Gbeta protein in the dimorphic fungal wheat pathogen Mycosphaerella graminicola, which we designated MgGpa1, MgGpa2, MgGpa3, and MgGpb1, respectively. Sequence comparisons and phylogenetic analyses showed that MgGPA1 and MgGPA3 are most related to the mammalian Galpha(i) and Galpha(s) families, respectively, whereas MgGPA2 is not related to either of these families. On potato dextrose agar (PDA) and in yeast glucose broth (YGB), MgGpa1 mutants produced significantly longer spores than those of the wild type (WT), and these developed into unique fluffy mycelia in the latter medium, indicating that this gene negatively controls filamentation. MgGpa3 mutants showed more pronounced yeast-like growth accompanied with hampered filamentation and secreted a dark-brown pigment into YGB. Germ tubes emerging from spores of MgGpb1 mutants were wavy on water agar and showed a nested type of growth on PDA that was due to hampered filamentation, numerous cell fusions, and increased anastomosis. Intracellular cyclic AMP (cAMP) levels of MgGpb1 and MgGpa3 mutants were decreased, indicating that both genes positively regulate the cAMP pathway, which was confirmed because the WT phenotype was restored by adding cAMP to these mutant cultures. The cAMP levels in MgGpa1 mutants and the WT were not significantly different, suggesting that this gene might be dispensable for cAMP regulation. In planta assays showed that mutants of MgGpa1, MgGpa3, and MgGpb1 are strongly reduced in pathogenicity. We concluded that the heterotrimeric G proteins encoded by MgGpa3 and MgGpb1 regulate the cAMP pathway that is required for development and pathogenicity in M. graminicola.
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Poli A, Di Pietro A, Zigon D, Lenasi H. Possible involvement of G-proteins and cAMP in the induction of progesterone hydroxylating enzyme system in the vascular wilt fungus Fusarium oxysporum. J Steroid Biochem Mol Biol 2009; 113:241-7. [PMID: 19429428 DOI: 10.1016/j.jsbmb.2009.01.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 11/06/2008] [Accepted: 01/13/2009] [Indexed: 11/19/2022]
Abstract
Fungi present the ability to hydroxylate steroids. In some filamentous fungi, progesterone induces an enzyme system which converts the compound into a less toxic hydroxylated product. We investigated the progesterone response in the vascular wilt pathogen Fusarium oxysporum, using mass spectrometry and high performance liquid chromatography (HPLC). Progesterone was mainly transformed into 15alpha-hydroxyprogesterone, which was found predominantly in the extracellular medium. The role of two conserved fungal signaling cascades in the induction of the progesterone-transforming enzyme system was studied, using knockout mutants lacking the mitogen-activated protein kinase Fmk1 or the heterotrimeric G-protein beta subunit Fgb1 functioning upstream of the cyclic adenosine monophosphate (cAMP) pathway. No steroid hydroxylation was induced in the Deltafgb1 strain, suggesting a role for the G-protein beta subunit in progesterone signaling. Exogenous cAMP restored the induction of progesterone-transforming activity in the Deltafgb1 strain, suggesting that steroid signaling in F. oxysporum is mediated by the cAMP-PKA pathway.
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Affiliation(s)
- Anna Poli
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Vrazov Trg 2, 1000 Ljubljana, Slovenia.
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Michielse CB, van Wijk R, Reijnen L, Cornelissen BJC, Rep M. Insight into the molecular requirements for pathogenicity of Fusarium oxysporum f. sp. lycopersici through large-scale insertional mutagenesis. Genome Biol 2009; 10:R4. [PMID: 19134172 PMCID: PMC2687792 DOI: 10.1186/gb-2009-10-1-r4] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 12/22/2008] [Accepted: 01/09/2009] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Fusarium oxysporum f. sp. lycopersici is the causal agent of vascular wilt disease in tomato. In order to gain more insight into the molecular processes in F. oxysporum necessary for pathogenesis and to uncover the genes involved, we used Agrobacterium-mediated insertional mutagenesis to generate 10,290 transformants and screened the transformants for loss or reduction of pathogenicity. RESULTS This led to the identification of 106 pathogenicity mutants. Southern analysis revealed that the average T-DNA insertion is 1.4 and that 66% of the mutants carry a single T-DNA. Using TAIL-PCR, chromosomal T-DNA flanking regions were isolated and 111 potential pathogenicity genes were identified. CONCLUSIONS Functional categorization of the potential pathogenicity genes indicates that certain cellular processes, such as amino acid and lipid metabolism, cell wall remodeling, protein translocation and protein degradation, seem to be important for full pathogenicity of F. oxysporum. Several known pathogenicity genes were identified, such as those encoding chitin synthase V, developmental regulator FlbA and phosphomannose isomerase. In addition, complementation and gene knock-out experiments confirmed that a glycosylphosphatidylinositol-anchored protein, thought to be involved in cell wall integrity, a transcriptional regulator, a protein with unknown function and peroxisome biogenesis are required for full pathogenicity of F. oxysporum.
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Affiliation(s)
- Caroline B Michielse
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands
| | - Ringo van Wijk
- Current address: Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands
| | - Linda Reijnen
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands
| | - Ben JC Cornelissen
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands
| | - Martijn Rep
- Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands
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López-Berges MS, DI Pietro A, Daboussi MJ, Wahab HA, Vasnier C, Roncero MIG, Dufresne M, Hera C. Identification of virulence genes in Fusarium oxysporum f. sp. lycopersici by large-scale transposon tagging. MOLECULAR PLANT PATHOLOGY 2009; 10:95-107. [PMID: 19161356 PMCID: PMC6640436 DOI: 10.1111/j.1364-3703.2008.00512.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Forward genetic screens are efficient tools for the dissection of complex biological processes, such as fungal pathogenicity. A transposon tagging system was developed in the vascular wilt fungus Fusarium oxysporum f. sp. lycopersici by inserting the novel modified impala element imp160::gfp upstream of the Aspergillus nidulans niaD gene, followed by transactivation with a constitutively expressed transposase. A collection of 2072 Nia(+) revertants was obtained from reporter strain T12 and screened for alterations in virulence, using a rapid assay for invasive growth on apple slices. Seven strains exhibited reduced virulence on both apple slices and intact tomato plants. Five of these were true revertants showing the re-insertion of imp160::gfp within or upstream of predicted coding regions, whereas the other two showed either excision without re-insertion or no excision. Linkage between imp160::gfp insertion and virulence phenotype was determined in four transposon-tagged loci using targeted deletion in the wild-type strain. Knockout mutants in one of the genes, FOXG_00016, displayed significantly reduced virulence, and complementation of the original revertant with the wild-type FOXG_00016 allele fully restored virulence. FOXG_00016 has homology to the velvet gene family of A. nidulans. The high rate of untagged virulence mutations in the T12 reporter strain appears to be associated with increased genetic instability, possibly as a result of the transactivation of endogenous transposable elements by the constitutively expressed transposase.
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Affiliation(s)
- Manuel Sánchez López-Berges
- Departamento de Genética, Universidad de Córdoba, Campus Universitario de Rabanales, Edif C5, 14071 Córdoba, Spain
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Yu HY, Seo JA, Kim JE, Han KH, Shim WB, Yun SH, Lee YW. Functional analyses of heterotrimeric G protein G alpha and G beta subunits in Gibberella zeae. MICROBIOLOGY-SGM 2008; 154:392-401. [PMID: 18227243 PMCID: PMC2885625 DOI: 10.1099/mic.0.2007/012260-0] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The homothallic ascomycete fungus Gibberella zeae (anamorph: Fusarium graminearum) is a major toxigenic plant pathogen that causes head blight disease on small-grain cereals. The fungus produces the mycotoxins deoxynivalenol (DON) and zearalenone (ZEA) in infected hosts, posing a threat to human and animal health. Despite its agricultural and toxicological importance, the molecular mechanisms underlying its growth, development and virulence remain largely unknown. To better understand such mechanisms, we studied the heterotrimeric G proteins of G. zeae, which are known to control crucial signalling pathways that regulate various cellular and developmental responses in fungi. Three putative Gα subunits, GzGPA1, GzGPA2 and GzGPA3, and one Gβ subunit, GzGPB1, were identified in the F. graminearum genome. Deletion of GzGPA1, a homologue of the Aspergillus nidulans Gα gene fadA, resulted in female sterility and enhanced DON and ZEA production, suggesting that GzGPA1 is required for normal sexual reproduction and repression of toxin biosynthesis. The production of DON and ZEA was also enhanced in the GzGPB1 mutant, suggesting that both GαGzGPA1 and GβGzGPB1 negatively control mycotoxin production. Deletion of GzGPA2, which encodes a Gα protein similar to A. nidulans GanB, caused reduced pathogenicity and increased chitin accumulation in the cell wall, implying that GzGPA2 has multiple functions. Our study shows that G. zeae heterotrimeric G protein subunits can regulate vegetative growth, sexual development, toxin production and pathogenicity.
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Affiliation(s)
- Hye-Young Yu
- School of Agricultural Biotechnology and Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921, Republic of Korea
| | - Jeong-Ah Seo
- School of Agricultural Biotechnology and Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921, Republic of Korea
| | - Jung-Eun Kim
- School of Agricultural Biotechnology and Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921, Republic of Korea
| | - Kap-Hoon Han
- Department of Pharmaceutical Engineering, Woosuk University, Wanju 565-701, Republic of Korea
| | - Won-Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843-2132, USA
| | - Sung-Hwan Yun
- Department of Medical Biotechnology, Soonchunhyang University, Asan 336-745, Republic of Korea
| | - Yin-Won Lee
- School of Agricultural Biotechnology and Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921, Republic of Korea
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Abstract
Filamentous fungi are multicellular eukaryotic organisms known for nutrient recycling as well as for antibiotic and food production. This group of organisms also contains the most devastating plant pathogens and several important human pathogens. Since the first report of heterotrimeric G proteins in filamentous fungi in 1993, it has been demonstrated that G proteins are essential for growth, asexual and sexual development, and virulence in both animal and plant pathogenic filamentous species. Numerous G protein subunit and G protein-coupled receptor genes have been identified, many from whole-genome sequences. Several regulatory pathways have now been delineated, including those for nutrient sensing, pheromone response and mating, and pathogenesis. This review provides a comparative analysis of G protein pathways in several filamentous species, with discussion of both unifying themes and important unique signaling paradigms.
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Affiliation(s)
- Liande Li
- Department of Plant Pathology and Microbiology, University of California, Riverside, California 92521, USA
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Vegetative hyphal fusion is not essential for plant infection by Fusarium oxysporum. EUKARYOTIC CELL 2007; 7:162-71. [PMID: 18039941 DOI: 10.1128/ec.00258-07] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Vegetative hyphal fusion (VHF) is a ubiquitous phenomenon in filamentous fungi whose biological role is poorly understood. In Neurospora crassa, the mitogen-activated protein kinase (MAPK) Mak-2 and the WW domain protein So are required for efficient VHF. A MAPK orthologous to Mak-2, Fmk1, was previously shown to be essential for root penetration and pathogenicity of the vascular wilt fungus Fusarium oxysporum. Here we took a genetic approach to test two hypotheses, that (i) VHF and plant infection have signaling mechanisms in common and (ii) VHF is required for efficient plant infection. F. oxysporum mutants lacking either Fmk1 or Fso1, an orthologue of N. crassa So, were impaired in the fusion of vegetative hyphae and microconidial germ tubes. Deltafmk1 Deltafso1 double mutants exhibited a more severe fusion phenotype than either single mutant, indicating that the two components function in distinct pathways. Both Deltafso1 and Deltafmk1 strains were impaired in the formation of hyphal networks on the root surface, a process associated with extensive VHF. The Deltafso1 mutants exhibited slightly reduced virulence in tomato fruit infection assays but, in contrast to Deltafmk1 strains, were still able to perform functions associated with invasive growth, such as secretion of pectinolytic enzymes or penetration of cellophane sheets, and to infect tomato plants. Thus, although VHF per se is not essential for plant infection, both processes have some signaling components in common, suggesting an evolutionary relationship between the underlying cellular mechanisms.
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Zhao X, Mehrabi R, Xu JR. Mitogen-activated protein kinase pathways and fungal pathogenesis. EUKARYOTIC CELL 2007; 6:1701-14. [PMID: 17715363 PMCID: PMC2043402 DOI: 10.1128/ec.00216-07] [Citation(s) in RCA: 265] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Xinhua Zhao
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
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Chen D, Janganan TK, Chen G, Marques ER, Kress MR, Goldman GH, Walmsley AR, Borges-Walmsley MI. The cAMP pathway is important for controlling the morphological switch to the pathogenic yeast form of Paracoccidioides brasiliensis. Mol Microbiol 2007; 65:761-79. [PMID: 17635191 PMCID: PMC2064555 DOI: 10.1111/j.1365-2958.2007.05824.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Paracoccidioides brasiliensis is a human pathogenic fungus that switches from a saprobic mycelium to a pathogenic yeast. Consistent with the morphological transition being regulated by the cAMP-signalling pathway, there is an increase in cellular cAMP levels both transiently at the onset (< 24 h) and progressively in the later stages (> 120 h) of the transition to the yeast form, and this transition can be modulated by exogenous cAMP. We have cloned the cyr1 gene encoding adenylate cyclase (AC) and established that its transcript levels correlate with cAMP levels. In addition, we have cloned the genes encoding three Gα (Gpa1–3), Gβ (Gpb1) and Gγ (Gpg1) G proteins. Gpa1 and Gpb1 interact with one another and the N-terminus of AC, but neither Gpa2 nor Gpa3 interacted with Gpb1 or AC. The interaction of Gpa1 with Gpb1 was blocked by GTP, but its interaction with AC was independent of bound nucleotide. The transcript levels for gpa1, gpb1 and gpg1 were similar in mycelium, but there was a transient excess of gpb1 during the transition, and an excess of gpa1 in yeast. We have interpreted our findings in terms of a novel signalling mechanism in which the activity of AC is differentially modulated by Gpa1 and Gpb1 to maintain the signal over the 10 days needed for the morphological switch.
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Affiliation(s)
- Daliang Chen
- Centre for Infectious Diseases, Wolfson Research Institute, School of Biological and Biomedical Sciences, University of Durham – Queen's CampusStockton-on-Tees TS17 6BH, UK.
| | - Thamarai K Janganan
- Centre for Infectious Diseases, Wolfson Research Institute, School of Biological and Biomedical Sciences, University of Durham – Queen's CampusStockton-on-Tees TS17 6BH, UK.
| | - Gongyou Chen
- Centre for Infectious Diseases, Wolfson Research Institute, School of Biological and Biomedical Sciences, University of Durham – Queen's CampusStockton-on-Tees TS17 6BH, UK.
| | - Everaldo R Marques
- Departamento de Ciencias Farmaceuticas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Av. do Cafe S/NCEP 14040-903, Ribeirao Preto, Sao Paulo, Brazil.
| | - Marcia R Kress
- Departamento de Ciencias Farmaceuticas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Av. do Cafe S/NCEP 14040-903, Ribeirao Preto, Sao Paulo, Brazil.
| | - Gustavo H Goldman
- Departamento de Ciencias Farmaceuticas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Av. do Cafe S/NCEP 14040-903, Ribeirao Preto, Sao Paulo, Brazil.
| | - Adrian R Walmsley
- Centre for Infectious Diseases, Wolfson Research Institute, School of Biological and Biomedical Sciences, University of Durham – Queen's CampusStockton-on-Tees TS17 6BH, UK.
- For correspondence. E-mail , ; Tel. (+44) (0)191 334 0465 or 0467; Fax (+44) (0)191 334 0468
| | - M Inês Borges-Walmsley
- Centre for Infectious Diseases, Wolfson Research Institute, School of Biological and Biomedical Sciences, University of Durham – Queen's CampusStockton-on-Tees TS17 6BH, UK.
- For correspondence. E-mail , ; Tel. (+44) (0)191 334 0465 or 0467; Fax (+44) (0)191 334 0468
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Sagaram US, Shim WB. Fusarium verticillioides GBB1, a gene encoding heterotrimeric G protein beta subunit, is associated with fumonisin B biosynthesis and hyphal development but not with fungal virulence. MOLECULAR PLANT PATHOLOGY 2007; 8:375-384. [PMID: 20507507 DOI: 10.1111/j.1364-3703.2007.00398.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Fusarium verticillioides (Sacc.) Nirenberg (teleomorph Gibberella moniliformis Wineland) is a maize pathogen that causes ear rots and stalk rots. The fungus also produces a group of mycotoxins, fumonisins, on infected ears, which cause considerable health and economic concerns for humans and animals worldwide. To date, our understanding of the molecular mechanisms associated with fungal virulence and fumonisin biosynthesis in F. verticillioides is limited. In this study, GBB1, a gene encoding a putative beta subunit of a heterotrimeric G protein, was disrupted and the effects on fumonisin biosynthesis and virulence were evaluated. A GBB1 deletion mutant (Deltagbb1) showed no significant differences in radial growth and mycelial mass but produced significantly less fumonisin B(1 )(FB(1)) than its wild-type progenitor. HPLC analysis showed that Deltagbb1 produced less than 10 p.p.m. FB(1) while the wild-type produced over 140 p.p.m. when strains were grown on cracked corn kernels. Reduced expression of the key FB(1 )biosynthetic genes, FUM1 and FUM8, in Deltagbb1 provides further evidence that GBB1 is involved in FB(1) regulation. Stalk rot virulence, as measured by mean lesion length and by area, was not significantly different in Deltagbb1 compared with the wild-type, suggesting that GBB1 does not regulate virulence in F. verticillioides. Developmentally, hyphae of Deltagbb1 do not deviate from the original axis of polarity established upon germ tube emergence in contrast to wild-type hyphae that meander on and off axis as they grow. Complementation of Deltagbb1 with GBB1 restored FB(1) production and hyphal growth to wild-type. The results of this study demonstrate that heterotrimeric G protein beta subunit plays an important role in regulation of FB(1) biosynthesis and hyphal growth, but not virulence in F. verticillioides.
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Affiliation(s)
- Uma Shankar Sagaram
- Department of Plant Pathology and Microbiology, Program for the Biology of Filamentous Fungi, Texas A&M University, College Station, TX 77843-2132, USA
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Jin QC, Dong HT, Peng YL, Chen BS, Shao J, Deng Y, Dai CE, Fang YQ, Lou YC, Li YZ, Li DB. Application of cDNA array for studying the gene expression profile of mature appressoria of Magnaporthe grisea. J Zhejiang Univ Sci B 2007; 8:88-97. [PMID: 17266183 PMCID: PMC1791059 DOI: 10.1631/jzus.2007.b0088] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Appressorium is an infection structure of the phytopathogenic fungus Magnaporthe grisea. Analysis of gene expression profiles of appressorium development provides insight into the molecular basis of pathogenicity and control of this fungal plant disease. A cDNA array representing 2927 unique genes based on a large EST (expressed sequence tag) database of M. grisea strain Y34 was constructed and used to profile the gene expression patterns at mycelium and appressorium maturation stages. Compared with mycelia, 55 up-regulated and 22 down-regulated genes were identified in mature appressoria. Among 77 genes, 16 genes showed no similarity to the genome sequences of M. grisea. A novel homologue of peptidyl-prolyl cis-trans isomerase was found to be expressed at low-level in mature appressoria of M. grisea. The results indicated that the genes such as pyruvate carboxylase, phospholipid metabolism-related protein and glyceraldehyde 3-phosphate dehydrogenase involved in gluconeogenesis, lipid metabolism and glycolysis, showed differential expression in mature appressoria. Furthermore, genes such as PTH11, beta subunit of G protein and SGT1 involved in cell signalling, were expressed differentially in mature appressoria. Northern blot analysis was used to confirm the cDNA array results.
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Affiliation(s)
- Qing-chao Jin
- Bioinformatics and Gene Network Research Group, School of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029, China
| | - Hai-tao Dong
- Bioinformatics and Gene Network Research Group, School of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029, China
- †E-mail:
| | - You-liang Peng
- Key Laboratory of Molecular Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100094, China
| | - Bao-shan Chen
- Laboratory of Subtropical Bioresource Conservation and Utilization, Guangxi University, Nanning 530004, China
| | - Jing Shao
- Bioinformatics and Gene Network Research Group, School of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029, China
| | - Ye Deng
- Bioinformatics and Gene Network Research Group, School of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029, China
| | - Cheng-en Dai
- Bioinformatics and Gene Network Research Group, School of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029, China
| | - Yong-qi Fang
- Bioinformatics and Gene Network Research Group, School of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029, China
| | - Yi-chun Lou
- Bioinformatics and Gene Network Research Group, School of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029, China
| | - You-zhi Li
- Laboratory of Subtropical Bioresource Conservation and Utilization, Guangxi University, Nanning 530004, China
| | - De-bao Li
- Bioinformatics and Gene Network Research Group, School of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029, China
- †E-mail:
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Hagen S, Marx F, Ram AF, Meyer V. The antifungal protein AFP from Aspergillus giganteus inhibits chitin synthesis in sensitive fungi. Appl Environ Microbiol 2007; 73:2128-34. [PMID: 17277210 PMCID: PMC1855660 DOI: 10.1128/aem.02497-06] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The antifungal protein AFP from Aspergillus giganteus is highly effective in restricting the growth of major human- and plant-pathogenic filamentous fungi. However, a fundamental prerequisite for the use of AFP as an antifungal drug is a complete understanding of its mode of action. In this study, we performed several analyses focusing on the assumption that the chitin biosynthesis of sensitive fungi is targeted by AFP. Here we show that the N-terminal domain of AFP (amino acids 1 to 33) is sufficient for efficient binding of AFP to chitin but is not adequate for inhibition of the growth of sensitive fungi. AFP susceptibility tests and SYTOX Green uptake experiments with class III and class V chitin synthase mutants of Fusarium oxysporum and Aspergillus oryzae showed that deletions made the fungi less sensitive to AFP and its membrane permeabilization effect. In situ chitin synthase activity assays revealed that chitin synthesis is specifically inhibited by AFP in sensitive fungi, indicating that AFP causes cell wall stress and disturbs cell integrity. Further evidence that there was AFP-induced cell wall stress was obtained by using an Aspergillus niger reporter strain in which the cell wall integrity pathway was strongly induced by AFP.
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Affiliation(s)
- Silke Hagen
- Berlin University of Technology, Institute of Biotechnology, Department Microbiology and Genetics, Gustav-Meyer-Allee 25, D-13355 Berlin, Germany
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Prados-Rosales RC, Serena C, Delgado-Jarana J, Guarro J, Di Pietro A. Distinct signalling pathways coordinately contribute to virulence of Fusarium oxysporum on mammalian hosts. Microbes Infect 2006; 8:2825-31. [PMID: 17095278 DOI: 10.1016/j.micinf.2006.08.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 07/03/2006] [Accepted: 08/30/2006] [Indexed: 11/23/2022]
Abstract
The filamentous fungus Fusarium oxysporum causes vascular wilt on a wide range of plant species and is an emerging pathogen of humans. A mitogen-activated protein kinase, Fmk1, and a G protein beta subunit, Fgb1, control pathogenicity of F. oxysporum on plants through distinct signalling pathways. In the present report, we studied the genetic interaction between fmk1 and fgb1 and their role in virulence on a mammalian host. The delta fmk1 or delta fgb1 single mutants exhibited similar virulence patterns as the wild type strain in an immunodepressed mouse model. By contrast, double mutants lacking both genes had dramatically reduced virulence. All mutants showed similar in vitro growth or tolerance to temperature and osmotic stress as the wild type strain. However, the delta fgb1 and delta fmk1 strains were reduced in specific extracellular protease activity or adhesion to fibronectin, respectively, two factors previously associated with fungal virulence. Thus, Fmk1 and Fgb1 are components of distinct signalling pathways which collectively control virulence of F. oxysporum on mammalian hosts.
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Affiliation(s)
- Rafael C Prados-Rosales
- Departamento de Genética, Universidad de Córdoba, Campus de Rabanales Edificio C5, 14071 Córdoba, Spain
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41
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Sagaram US, Butchko RAE, Shim WB. The putative monomeric G-protein GBP1 is negatively associated with fumonisin B production in Fusarium verticillioides. MOLECULAR PLANT PATHOLOGY 2006; 7:381-389. [PMID: 20507454 DOI: 10.1111/j.1364-3703.2006.00347.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
SUMMARY Fumonisin B(1) (FB(1)) is a mycotoxin produced by Fusarium verticillioides that contaminates maize. FB(1) has been linked to a number of human and animal mycotoxicoses worldwide. Despite its significance, our understanding of the FB(1) biosynthesis regulatory mechanisms is limited. Here, we describe F. verticillioides GBP1, encoding a monomeric G-protein, and its role in FB(1) biosynthesis. GBP1 was discovered as an expressed sequence tag (EST) up-regulated in the F. verticillioides fcc1 mutant that showed reduced conidiation and no FB(1) biosynthesis when grown on maize kernels. Sequence analysis showed that GBP1 encodes a putative 368-amino-acid protein with similarity to DRG and Obg subclasses of G-proteins that are involved in development and stress responses. A GBP1 knockout mutant (Deltagbp1) exhibited normal growth, but increased FB(1) production (> 58%) compared with the wild-type when grown on corn kernels. Complementation of Deltagbp1 with the wild-type GBP1 gene restored FB(1) production levels to that of the wild-type. Our data indicate that GBP1 is negatively associated with FB(1) biosynthesis but not with conidiation in F. verticillioides. The deletion of GBP1 led to up-regulation of key FB(1) biosynthetic genes, FUM1 and FUM8, suggesting that the increased FB(1) production in Deltagbp1 is due to over-expression of FUM genes.
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Affiliation(s)
- Uma Shankar Sagaram
- Department of Plant Pathology and Microbiology, Program for the Biology of Filamentous Fungi, Texas A&M University, College Station, TX 77843-2132, USA
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Delgado-Jarana J, Sousa S, González F, Rey M, Llobell A. ThHog1 controls the hyperosmotic stress response in Trichoderma harzianum. Microbiology (Reading) 2006; 152:1687-1700. [PMID: 16735732 DOI: 10.1099/mic.0.28729-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Trichoderma harzianumis a widespread mycoparasitic fungus, able to successfully colonize a wide range of substrates under different environmental conditions. Transcript profiling revealed a subset of genes induced inT. harzianumunder hyperosmotic shock. Thehog1gene, a homologue of the MAPKHOG1gene that controls the hyperosmotic stress response inSaccharomyces cerevisiae, was characterized.T. harzianum hog1complemented thehog1Δ mutation inS. cerevisiae, but showed different features to yeast alleles: improved osmoresistance by expression of thehog1allele and a lack of lethality when thehog1F315Sallele was overexpressed. ThHog1 protein was phosphorylated inT. harzianumunder different stress conditions such as hyperosmotic or oxidative stress, among others. By using a ThHog1-GFP fusion, the protein was shown to be localized in nuclei under these stress conditions. Two mutant strains ofT. harzianumwere constructed: one carrying thehog1F315Sallele, and a knockdownhog1-silenced strain. The silenced strain was highly sensitive to osmotic stress, and showed intermediate levels of resistance against oxidative stress, indicating that the main role of ThHog1 protein is in the hyperosmotic stress response. Stress cross-resistance experiments showed evidences of a secondary role of ThHog1 in oxidative stress. The strain carrying thehog1F315Sallele was highly resistant to the calcineurin inhibitor cyclosporin A, which suggests the existence of links between the two pathways. The two mutant strains showed a strongly reduced antagonistic activity against the plant pathogensPhoma betaeandColletotrichum acutatum, which points to a role of ThHog1 protein in fungus–fungus interactions.
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Affiliation(s)
- Jesús Delgado-Jarana
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla/CSIC, CIC Isla de la Cartuja, Sevilla, Spain
| | - Sonia Sousa
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla/CSIC, CIC Isla de la Cartuja, Sevilla, Spain
| | - Fran González
- Newbiotechnic SA, Parque Industrial Bollullos de la Mitación, Sevilla, Spain
| | - Manuel Rey
- Newbiotechnic SA, Parque Industrial Bollullos de la Mitación, Sevilla, Spain
| | - Antonio Llobell
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla/CSIC, CIC Isla de la Cartuja, Sevilla, Spain
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