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Vandermeulen MD, Lorenz MC, Cullen PJ. Conserved signaling modules regulate filamentous growth in fungi: a model for eukaryotic cell differentiation. Genetics 2024; 228:iyae122. [PMID: 39239926 PMCID: PMC11457945 DOI: 10.1093/genetics/iyae122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 07/20/2024] [Indexed: 09/07/2024] Open
Abstract
Eukaryotic organisms are composed of different cell types with defined shapes and functions. Specific cell types are produced by the process of cell differentiation, which is regulated by signal transduction pathways. Signaling pathways regulate cell differentiation by sensing cues and controlling the expression of target genes whose products generate cell types with specific attributes. In studying how cells differentiate, fungi have proved valuable models because of their ease of genetic manipulation and striking cell morphologies. Many fungal species undergo filamentous growth-a specialized growth pattern where cells produce elongated tube-like projections. Filamentous growth promotes expansion into new environments, including invasion into plant and animal hosts by fungal pathogens. The same signaling pathways that regulate filamentous growth in fungi also control cell differentiation throughout eukaryotes and include highly conserved mitogen-activated protein kinase (MAPK) pathways, which is the focus of this review. In many fungal species, mucin-type sensors regulate MAPK pathways to control filamentous growth in response to diverse stimuli. Once activated, MAPK pathways reorganize cell polarity, induce changes in cell adhesion, and promote the secretion of degradative enzymes that mediate access to new environments. However, MAPK pathway regulation is complicated because related pathways can share components with each other yet induce unique responses (i.e. signal specificity). In addition, MAPK pathways function in highly integrated networks with other regulatory pathways (i.e. signal integration). Here, we discuss signal specificity and integration in several yeast models (mainly Saccharomyces cerevisiae and Candida albicans) by focusing on the filamentation MAPK pathway. Because of the strong evolutionary ties between species, a deeper understanding of the regulation of filamentous growth in established models and increasingly diverse fungal species can reveal fundamentally new mechanisms underlying eukaryotic cell differentiation.
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Affiliation(s)
| | - Michael C Lorenz
- Department of Microbiology and Molecular Genetics, University of Texas McGovern Medical School, Houston, TX 77030, USA
| | - Paul J Cullen
- Department of Biological Sciences, University at Buffalo, Buffalo, NY 14260-1300, USA
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Cao H, Gong H, Yu M, Pan X, Song T, Yu J, Qi Z, Du Y, Zhang R, Liu Y. The Ras GTPase-activating protein UvGap1 orchestrates conidiogenesis and pathogenesis in the rice false smut fungus Ustilaginoidea virens. MOLECULAR PLANT PATHOLOGY 2024; 25:e13448. [PMID: 38502297 PMCID: PMC10950028 DOI: 10.1111/mpp.13448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 12/27/2023] [Accepted: 01/30/2024] [Indexed: 03/21/2024]
Abstract
Ras GTPase-activating proteins (Ras GAPs) act as negative regulators for Ras proteins and are involved in various signalling processes that influence cellular functions. Here, the function of four Ras GAPs, UvGap1 to UvGap4, was identified and analysed in Ustilaginoidea virens, the causal agent of rice false smut disease. Disruption of UvGAP1 or UvGAP2 resulted in reduced mycelial growth and an increased percentage of larger or dumbbell-shaped conidia. Notably, the mutant ΔUvgap1 completely lost its pathogenicity. Compared to the wild-type strain, the mutants ΔUvgap1, ΔUvgap2 and ΔUvgap3 exhibited reduced tolerance to H2 O2 oxidative stress. In particular, the ΔUvgap1 mutant was barely able to grow on the H2 O2 plate, and UvGAP1 was found to influence the expression level of genes involved in reactive oxygen species synthesis and scavenging. The intracellular cAMP level in the ΔUvgap1 mutant was elevated, as UvGap1 plays an important role in maintaining the intracellular cAMP level by affecting the expression of phosphodiesterases, which are linked to cAMP degradation in U. virens. In a yeast two-hybrid assay, UvRas1 and UvRasGef (Ras guanyl nucleotide exchange factor) physically interacted with UvGap1. UvRas2 was identified as an interacting partner of UvGap1 through a bimolecular fluorescence complementation assay and affinity capture-mass spectrometry analysis. Taken together, these findings suggest that the UvGAP1-mediated Ras pathway is essential for the development and pathogenicity of U. virens.
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Affiliation(s)
- Huijuan Cao
- Institute of Plant ProtectionJiangsu Academy of Agricultural SciencesNanjingChina
| | - Hao Gong
- Institute of Plant ProtectionJiangsu Academy of Agricultural SciencesNanjingChina
| | - Mina Yu
- Institute of Plant ProtectionJiangsu Academy of Agricultural SciencesNanjingChina
| | - Xiayan Pan
- Institute of Plant ProtectionJiangsu Academy of Agricultural SciencesNanjingChina
| | - Tianqiao Song
- Institute of Plant ProtectionJiangsu Academy of Agricultural SciencesNanjingChina
| | - Junjie Yu
- Institute of Plant ProtectionJiangsu Academy of Agricultural SciencesNanjingChina
| | - Zhongqiang Qi
- Institute of Plant ProtectionJiangsu Academy of Agricultural SciencesNanjingChina
| | - Yan Du
- Institute of Plant ProtectionJiangsu Academy of Agricultural SciencesNanjingChina
| | - Rongsheng Zhang
- Institute of Plant ProtectionJiangsu Academy of Agricultural SciencesNanjingChina
| | - Yongfeng Liu
- Institute of Plant ProtectionJiangsu Academy of Agricultural SciencesNanjingChina
- College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
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Yu L, Yang Y, Qiu X, Xiong D, Tian C. The mitogen-activated protein kinase module CcSte11-CcSte7-CcPmk1 regulates pathogenicity via the transcription factor CcSte12 in Cytospora chrysosperma. STRESS BIOLOGY 2024; 4:4. [PMID: 38225467 PMCID: PMC10789715 DOI: 10.1007/s44154-023-00142-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 11/28/2023] [Indexed: 01/17/2024]
Abstract
The pathogen Cytospora chrysosperma is the causal agent of poplar canker disease and causes considerable economic losses in China. Mitogen-activated protein kinase (MAPK) cascades play a crucial role in mediating cellular responses and Pmk1-MAPKs are indispensable for pathogenic related processes in plant pathogenic fungi. In previous studies, we demonstrated that the CcPmk1 acts as a core regulator of fungal pathogenicity by modulating a small number of master downstream targets, such as CcSte12. In this study, we identified and characterized two upstream components of CcPmk1: MAPKKK CcSte11 and MAPKK CcSte7. Deletion of CcSte11 and CcSte7, resulted in slowed growth, loss of sporulation and virulence, similar to the defects observed in the CcPmk1 deletion mutant. In addition, CcSte11, CcSte7 and CcPmk1 interact with each other, and the upstream adaptor protein CcSte50 interact with CcSte11 and CcSte7. Moreover, we explored the global regulation network of CcSte12 by transcriptional analysis between CcSte12 deletion mutants and wild-type during the simulated infection process. Two hydrolase activity GO terms (GO:0004553 and GO:0016798) and starch and sucrose metabolism (mgr00500) KEGG pathway were significantly enriched in the down-regulated genes of CcSte12 deletion mutants. In addition, a subset of glycosyl hydrolase genes and putative effector genes were significantly down-regulated in the CcSte12 deletion mutant, which might be important for fungal pathogenicity. Especially, CcSte12 bound to the CcSp84 promoter region containing the TGAAACA motif. Moreover, comparison of CcSte12-regulated genes with CcPmk1-regulated genes revealed 116 overlapping regulated genes in both CcSte12 and CcPmk1, including some virulence-associated genes. Taken together, the protein complexes CcSte11-CcSte7-CcPmk1 receive signals transmitted by upstream CcSte50 and transmit signals to downstream CcSte12, which regulates hydrolase, effectors and other genes to promote virulence. Overall, these results indicate that the CcPmk1-MAPK signaling pathway of C. chrysosperma plays a key role in the pathogenicity.
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Affiliation(s)
- Lu Yu
- State Key Laboratory of Efficient Production of Forest Resources, Beijing, China
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing, 100083, China
| | - Yuchen Yang
- State Key Laboratory of Efficient Production of Forest Resources, Beijing, China
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing, 100083, China
| | - Xiaolin Qiu
- State Key Laboratory of Efficient Production of Forest Resources, Beijing, China
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing, 100083, China
| | - Dianguang Xiong
- State Key Laboratory of Efficient Production of Forest Resources, Beijing, China.
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing, 100083, China.
| | - Chengming Tian
- State Key Laboratory of Efficient Production of Forest Resources, Beijing, China.
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing, 100083, China.
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Xiao Y, Lv W, Tong Q, Xu Z, Wang Z. The RasGEF MoCdc25 regulates vegetative growth, conidiation and appressorium-mediated infection in the rice blast fungus Magnaporthe oryzae. Fungal Genet Biol 2023; 168:103825. [PMID: 37460083 DOI: 10.1016/j.fgb.2023.103825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/26/2023]
Abstract
Ras guanine nucleotide exchange factors (RasGEFs) can trigger Ras GTPase activities and play important roles in controlling various cellular processes in eukaryotes. Recently, it has been exhibited that RasGEF Cdc25 regulates morphological differentiation and pathogenicity in several plant pathogenic fungi. However, the role of RasGEFs in Magnaporthe oryzae is largely unknown. In this study, we identified and functionally characterized a RasGEF gene MoCDC25 in M. oryzae, which is orthologous to Saccharomyces cerevisiae CDC25. Targeted gene deletion mutants (ΔMocdc25) were completely nonpathogenic and were severely impaired in hyphal growth, conidiation and appressorium formation. The mutants exhibited highly sensitive response to osmotic, cell wall integrity or oxidative stresses. MoCdc25 physically interacts with the MAPK scaffold Mst50 and the putative Cdc42GEF MoScd1 in yeast two-hybrid assays. Moreover, we found that MoCdc25 was involved in regulating the phosphorylation of the MAP kinases (Pmk1, Mps1, and Osm1). In addition, the intracellular cAMP content in hyphae of the ΔMocdc25 mutants was significantly reduced compared to the parent strain Ku80 and the defect of appressorium formation of the mutants could be partially restored by the supplement of exogenous cAMP. Taken together, we conclude that the RasGEF MoCdc25 regulates vegetative growth, conidiation, appressorium formation and pathogenicity via MAPK and cAMP response pathways in M. oryzae.
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Affiliation(s)
- Yu Xiao
- State Key Laboratory of Rice Biology and Breeding & Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Wuyun Lv
- State Key Laboratory of Rice Biology and Breeding & Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Qi Tong
- State Key Laboratory of Rice Biology and Breeding & Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Zhe Xu
- State Key Laboratory of Rice Biology and Breeding & Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Zhengyi Wang
- State Key Laboratory of Rice Biology and Breeding & Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
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Yang C, Sun J, Wu Z, Jiang M, Li D, Wang X, Zhou C, Liu X, Ren Z, Wang J, Sun M, Sun W, Gao J. FoRSR1 Is Important for Conidiation, Fusaric Acid Production, and Pathogenicity in Fusarium oxysporum f. sp. ginseng. PHYTOPATHOLOGY 2023; 113:1244-1253. [PMID: 36706002 DOI: 10.1094/phyto-10-22-0372-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The root rot disease caused by Fusarium oxysporum f. sp. ginseng is one of the most destructive diseases of ginseng, an economically important herb. However, little is known about the pathogen's toxin biosynthesis or the molecular mechanisms regulating infection of ginseng. In this study we identified and functionally characterized the FoRSR1 gene that encodes a Ras-related (RSR) small GTPase homologous to yeast Rsr1 in F. oxysporum f. sp. ginseng. Disruption of FoRSR1 resulted in a significant reduction in mycelial dry weight in liquid cultures, although vegetative growth rate was not affected on culture plates. Notably, the Forsr1 mutant exhibited blunted and swollen hyphae with multi-nucleated compartments. It produced fewer and morphologically abnormal conidia and was defective in chlamydospore formation. In infection assays with ginseng roots, the Forsr1 mutant was significantly less virulent and caused only limited necrosis at the wounding sites. Deletion of FoRSR1 also affected pigmentation, autophagy, and production of fusaric acid. Furthermore, the expression of many candidate genes involved in secondary metabolism was significantly downregulated in the mutant, suggesting that FoRSR1 is also important for secondary metabolism. Overall, our results indicated that FoRSR1 plays important roles in conidiation, vacuolar morphology, secondary metabolism, and pathogenesis in F. oxysporum f. sp. ginseng.
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Affiliation(s)
- Cui Yang
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
- State Key Laboratory of North China Crop Improvement and Regulation, Hebei Agricultural University, Baoding, Hebei, 071000, China
| | - Jing Sun
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
| | - Zhaoqun Wu
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
| | - Maozhu Jiang
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
| | - Dayong Li
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
| | - Xinjie Wang
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
| | - Chunxiang Zhou
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
| | - Xuecheng Liu
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
| | - Zhiguo Ren
- State Key Laboratory of North China Crop Improvement and Regulation, Hebei Agricultural University, Baoding, Hebei, 071000, China
| | - Jun Wang
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
| | - Manli Sun
- State Key Laboratory of North China Crop Improvement and Regulation, Hebei Agricultural University, Baoding, Hebei, 071000, China
| | - Wenxian Sun
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
| | - Jie Gao
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
- State-Local Joint Engineering Research Center of Ginseng Breeding and Application, Changchun, 130118, China
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Qian H, Sun L, Wu M, Zhao W, Liu M, Liang S, Zhu X, Li L, Su Z, Lu J, Lin F, Liu X. The COPII subunit MoSec24B is involved in development, pathogenicity and autophagy in the rice blast fungus. FRONTIERS IN PLANT SCIENCE 2023; 13:1074107. [PMID: 36699840 PMCID: PMC9868959 DOI: 10.3389/fpls.2022.1074107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 12/08/2022] [Indexed: 06/17/2023]
Abstract
The endoplasmic reticulum (ER) acts as the starting point of the secretory pathway, where approximately one-third of the proteins are correctly folded and modified, loaded into vesicles, and transported to the Golgi for further processing and modification. In this process, COPII vesicles are responsible for transporting cargo proteins from the ER to the Golgi. Here, we identified the inner shell subunit of COPII vesicles (MoSec24B) and explored the importance of MoSec24B in the rice blast fungus. The targeted disruption of MoSec24B led to decreased growth, reduced conidiation, restricted glycogen and lipids utilization, sensitivity to the cell wall and hypertonic stress, the failure of septin-mediated repolarization of appressorium, impaired appressorium turgor pressure, and decreased ability to infect, which resulted in reduced pathogenicity to the host plant. Furthermore, MoSec24B functions in the three mitogen-activated protein kinase (MAPK) signaling pathways by acting with MoMst50. Deletion of MoSec24B caused reduced lipidation of MoAtg8, accelerated degradation of exogenously introduced GFP-MoAtg8, and increased lipidation of MoAtg8 upon treatment with a late inhibitor of autophagy (BafA1), suggesting that MoSec24B regulates the fusion of late autophagosomes with vacuoles. Together, these results suggest that MoSec24B exerts a significant role in fungal development, the pathogenesis of filamentous fungi and autophagy.
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Affiliation(s)
- Hui Qian
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Lixiao Sun
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Minghua Wu
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Wenhui Zhao
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Mengyu Liu
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Shuang Liang
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Xueming Zhu
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Lin Li
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Zhenzhu Su
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Jianping Lu
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Fucheng Lin
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Xiaohong Liu
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
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The Paxillin MoPax1 Activates Mitogen-Activated Protein (MAP) Kinase Signaling Pathways and Autophagy through MAP Kinase Activator MoMka1 during Appressorium-Mediated Plant Infection by the Rice Blast Fungus Magnaporthe oryzae. mBio 2022; 13:e0221822. [PMID: 36314807 PMCID: PMC9765475 DOI: 10.1128/mbio.02218-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Paxillin is a focal adhesion-associated protein that functions as an adaptor to recruit diverse cytoskeleton and signaling molecules into a complex and plays a crucial role in several signaling pathways in mammal cells. However, paxillin-mediated signal pathways are largely unknown in phytopathogenic fungi. Previously, Pax1 of Magnaporthe oryzae (MoPax1), a paxillin-like protein, has been identified as a crucial pathogenicity determinant. Here, we report the identification of a mitogen-activated protein (MAP) kinase (MAPK) activator, Mka1 of M. oryzae (MoMka1), that physically interacts with MoPax1. Targeted gene deletion of MoMKA1 resulted in pleiotropic defects in aerial hyphal growth, conidiation, appressorium formation, and pathogenicity in M. oryzae. MoMka1 interacts with Mst50, an adaptor protein of the Mst11-Mst7-Pmk1 and Mck1-Mkk2-Mps1 cascades. Moreover, the phosphorylation levels of both Pmk1 and Mps1 in aerial hyphae of the ΔMomka1 mutant were significantly reduced, indicating that MoMka1 acts upstream from the MAPK pathways. Interestingly, we found that MoMka1 interacts with MoAtg6 and MoAtg13. Deletion of MoMKA1 led to impaired MoAtg13 phosphorylation and enhanced autophagic flux under nutrient-rich conditions, indicating that MoMka1 is required for regulation of autophagy in M. oryzae. Taken together, the paxillin MoPax1 may activate MAP kinase signaling pathways and autophagy through MAP kinase activator MoMka1 and play important roles during appressorium-mediated plant infection by the rice blast fungus. IMPORTANCE Paxillin, as an adaptor recruiting diverse cytoskeleton and signaling molecules into a complex, plays a crucial role in several signaling pathways in mammal cells. However, paxillin-mediated signal pathways are largely unknown in phytopathogenic fungi. Here, we identified that MoMka1 physically interacts with MoPax1. Furthermore, MoMka1 acts upstream from the MAPK pathways through interacting with Mst50, a key protein of the Mst11-Mst7-Pmk1 and Mck1-Mkk2-Mps1 cascades. Meanwhile, MoMka1 interacts with both MoAtg6 and MoAtg13 and controls autophagy initiation by influencing the phosphorylation level of MoAtg13. In summary, we describe a model in which MoPax1 activates MAP kinase signaling pathways and autophagy through MoMka1 during appressorium-mediated plant infection by M. oryzae.
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Cai X, Xiang S, He W, Tang M, Zhang S, Chen D, Zhang X, Liu C, Li G, Xing J, Li Y, Chen X, Nie Y. Deubiquitinase Ubp3 regulates ribophagy and deubiquitinates Smo1 for appressorium-mediated infection by Magnaporthe oryzae. MOLECULAR PLANT PATHOLOGY 2022; 23:832-844. [PMID: 35220670 PMCID: PMC9104258 DOI: 10.1111/mpp.13196] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/09/2022] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
The Ubp family of deubiquitinating enzymes has been found to play important roles in plant-pathogenic fungi, but their regulatory mechanisms are still largely unknown. In this study, we revealed the regulatory mechanism of the deubiquitinating enzyme Ubp3 during the infection process of Magnaporthe oryzae. AUBP3 deletion mutant was severely defective in appressorium turgor accumulation, leading to the impairment of appressorial penetration. During appressorium formation, the mutant was also defective in glycogen and lipid metabolism. Interestingly, we found that nitrogen starvation and rapamycin treatment induced the ribophagy process in M. oryzae, which is closely dependent on Ubp3. In the ∆ubp3 mutant, the ribosome proteins and rRNAs were not well degraded on nitrogen starvation and rapamycin treatment. We also found that Ubp3 interacted with the GTPase-activating protein Smo1 and regulated its de-ubiquitination. Ubp3-dependent de-ubiquitination of Smo1 may be required for Smo1 to coordinate Ras signalling. Taken together, our results showed at least two roles of Ubp3 in M. oryzae: it regulates the ribophagy process and it regulates de-ubiquitination of GTPase-activating protein Smo1 for appressorium-mediated infection.
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Affiliation(s)
- Xuan Cai
- Laboratory of Physiological Plant PathologySouth China Agricultural UniversityGuangzhouChina
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Shikun Xiang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Wenhui He
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Mengxi Tang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Shimei Zhang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Deng Chen
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Xinrong Zhang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Caiyun Liu
- Laboratory of Physiological Plant PathologySouth China Agricultural UniversityGuangzhouChina
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Guotian Li
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Junjie Xing
- State Key Laboratory of Hybrid RiceHunan Hybrid Rice Research CenterChangshaChina
| | - Yunfeng Li
- Laboratory of Physiological Plant PathologySouth China Agricultural UniversityGuangzhouChina
| | - Xiao‐Lin Chen
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei ProvinceCollege of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Yanfang Nie
- Laboratory of Physiological Plant PathologySouth China Agricultural UniversityGuangzhouChina
- College of Materials and EnergySouth China Agricultural UniversityGuangzhouChina
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Qu Y, Cao H, Huang P, Wang J, Liu X, Lu J, Lin FC. A kelch domain cell end protein, PoTea1, mediates cell polarization during appressorium morphogenesis in Pyricularia oryzae. Microbiol Res 2022; 259:126999. [DOI: 10.1016/j.micres.2022.126999] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 02/08/2022] [Accepted: 02/27/2022] [Indexed: 01/01/2023]
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10
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Zhang X, Wang Z, Jiang C, Xu JR. Regulation of biotic interactions and responses to abiotic stresses by MAP kinase pathways in plant pathogenic fungi. STRESS BIOLOGY 2021; 1:5. [PMID: 37676417 PMCID: PMC10429497 DOI: 10.1007/s44154-021-00004-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 07/19/2021] [Indexed: 09/08/2023]
Abstract
Like other eukaryotes, fungi use MAP kinase (MAPK) pathways to mediate cellular changes responding to external stimuli. In the past two decades, three well-conserved MAP kinase pathways have been characterized in various plant pathogenic fungi for regulating responses and adaptations to a variety of biotic and abiotic stresses encountered during plant infection or survival in nature. The invasive growth (IG) pathway is homologous to the yeast pheromone response and filamentation pathways. In plant pathogens, the IG pathway often is essential for pathogenesis by regulating infection-related morphogenesis, such as appressorium formation, penetration, and invasive growth. The cell wall integrity (CWI) pathway also is important for plant infection although the infection processes it regulates vary among fungal pathogens. Besides its universal function in cell wall integrity, it often plays a minor role in responses to oxidative and cell wall stresses. Both the IG and CWI pathways are involved in regulating known virulence factors as well as effector genes during plant infection and mediating defenses against mycoviruses, bacteria, and other fungi. In contrast, the high osmolarity growth (HOG) pathway is dispensable for virulence in some fungi although it is essential for plant infection in others. It regulates osmoregulation in hyphae and is dispensable for appressorium turgor generation. The HOG pathway also plays a major role for responding to oxidative, heat, and other environmental stresses and is overstimulated by phenylpyrrole fungicides. Moreover, these three MAPK pathways crosstalk and coordinately regulate responses to various biotic and abiotic stresses. The IG and CWI pathways, particularly the latter, also are involved in responding to abiotic stresses to various degrees in different fungal pathogens, and the HOG pathway also plays a role in interactions with other microbes or fungi. Furthermore, some infection processes or stress responses are co-regulated by MAPK pathways with cAMP or Ca2+/CaM signaling. Overall, functions of individual MAP kinase pathways in pathogenesis and stress responses have been well characterized in a number of fungal pathogens, showing the conserved genetic elements with diverged functions, likely by rewiring transcriptional regulatory networks. In the near future, applications of genomics and proteomics approaches will likely lead to better understanding of crosstalk among the MAPKs and with other signaling pathways as well as roles of MAPKs in defense against other microbes (biotic interactions).
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Affiliation(s)
- Xue Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Zeyi Wang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Cong Jiang
- State Key Laboratory of Crop Stress Biology for Arid Areas and NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jin-Rong Xu
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.
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11
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Shi H, Meng S, Qiu J, Wang C, Shu Y, Luo C, Kou Y. MoWhi2 regulates appressorium formation and pathogenicity via the MoTor signalling pathway in Magnaporthe oryzae. MOLECULAR PLANT PATHOLOGY 2021; 22:969-983. [PMID: 34036714 PMCID: PMC8295519 DOI: 10.1111/mpp.13074] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/13/2021] [Accepted: 04/21/2021] [Indexed: 05/17/2023]
Abstract
Magnaporthe oryzae causes rice blast disease, which seriously threatens the safety of food production. Understanding the mechanism of appressorium formation, which is one of the key steps for successful infection by M. oryzae, is helpful to formulate effective control strategies of rice blast. In this study, we identified MoWhi2, the homolog of Saccharomyces cerevisiae Whi2 (Whisky2), as an important regulator that controls appressorium formation in M. oryzae. When MoWHI2 was disrupted, multiple appressoria were formed by one conidium and pathogenicity was significantly reduced. A putative phosphatase, MoPsr1, was identified to interact with MoWhi2 using a yeast two-hybridization screening assay. The knockout mutant ΔMopsr1 displayed similar phenotypes to the ΔMowhi2 strain. Both the ΔMowhi2 and ΔMopsr1 mutants could form appressoria on a hydrophilic surface with cAMP levels increasing in comparison with the wild type (WT). The conidia of ΔMowhi2 and ΔMopsr1 formed a single appressorium per conidium, similar to WT, when the target of rapamycin (TOR) inhibitor rapamycin was present. In addition, compared with WT, the expression levels of MoTOR and the MoTor signalling activation marker gene MoRS3 were increased, suggesting that inappropriate activation of the MoTor signalling pathway is one of the important reasons for the defects in appressorium formation in the ΔMowhi2 and ΔMopsr1 strains. Our results provide insights into MoWhi2 and MoPsr1-mediated appressorium development and pathogenicity by regulating cAMP levels and the activation of MoTor signalling in M. oryzae.
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Affiliation(s)
- Huanbin Shi
- State Key Laboratory of Rice BiologyChina National Rice Research InstituteHangzhouChina
| | - Shuai Meng
- State Key Laboratory of Rice BiologyChina National Rice Research InstituteHangzhouChina
- Hubei Key Lab of Plant Pathology, and College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Jiehua Qiu
- State Key Laboratory of Rice BiologyChina National Rice Research InstituteHangzhouChina
| | - Congcong Wang
- State Key Laboratory of Rice BiologyChina National Rice Research InstituteHangzhouChina
| | - Yazhou Shu
- State Key Laboratory of Rice BiologyChina National Rice Research InstituteHangzhouChina
| | - Chaoxi Luo
- Hubei Key Lab of Plant Pathology, and College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Yanjun Kou
- State Key Laboratory of Rice BiologyChina National Rice Research InstituteHangzhouChina
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12
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Wang X, Lu D, Tian C. Mitogen-activated protein kinase cascade CgSte50-Ste11-Ste7-Mk1 regulates infection-related morphogenesis in the poplar anthracnose fungus Colletotrichum gloeosporioides. Microbiol Res 2021; 248:126748. [PMID: 33752111 DOI: 10.1016/j.micres.2021.126748] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 11/28/2022]
Abstract
The hemibiotrophic pathogen Colletotrichum gloeosporioides is the causal agent of poplar anthracnose and causes considerable economic losses. This fungus infects its host through a specialized structure called an appressorium. In a previous study, we demonstrated that the mitogen-activated protein kinase (MAPK) CgMk1 plays a critical role in appressorium formation and pathogenicity. In this study, we identified three upstream components of CgMk1, the putative adaptor protein CgSte50, MAPKKK CgSte11, and MAPKK CgSte7, and showed that CgSte50, CgSte11, and CgSte7 positively regulate the phosphorylation of CgMk1. Deletion of CgSte50, CgSte11, and CgSte7 resulted in the loss of appressorium formation, penetration of the cellophane membrane, invasive growth and pathogenicity, similar to the defects observed in the CgMk1 mutant. CgSte50, CgSte11, CgSte7 and CgMk1 were also required for polarity during conidial germination. At the initial stage of appressorium formation, the accumulation of reactive oxygen species (ROS) was altered in the CgSte50, CgSte11, CgSte7 and CgMk1 deletion mutants compared with that in wild type (WT). Furthermore, the CgSte50, CgSte11, CgSte7 and CgMk1 deletion mutants manifested pleiotropic defects during vegetative growth; all mutants exhibited albino colonies, and the aerial hyphae had reduced hydrophobicity. In the mutants, autolysis was detected at the colony edge, and septum formation in the hyphae was elevated compared with that in the WT hyphae. Moreover, deletion of CgSte50, CgSte11, CgSte7 and CgMk1 affected vegetative growth under nitrogen-limiting and osmotic stress conditions. CgSte50, CgSte11, and CgSte7 but not CgMk1 were required for the oxidative stress response. Taken together, these results indicate that the CgMk1 MAPK cascade plays vital roles in various important functions in C. gloeosporioides.
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Affiliation(s)
- Xiaolian Wang
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Dongxiao Lu
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China.
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13
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Ras2 is important for growth and pathogenicity in Fusarium circinatum. Fungal Genet Biol 2021; 150:103541. [PMID: 33639303 DOI: 10.1016/j.fgb.2021.103541] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 11/21/2022]
Abstract
In this study, we investigated to possible role of Ras2 in Fusarium circinatum- a fungus that causes pine pitch canker disease on many different pine species and has a wide geographic distribution. This protein is encoded by the RAS2 gene and has been shown to control growth and pathogenicity in a number of fungi in a mitogen-activated protein kinase- and/or cyclic adenosyl monophosphate pathway-dependent manner. The aim was therefore to characterize the phenotypes of RAS2 gene knockout and complementation mutants of F. circinatum. These mutants were generated by transforming protoplasts of the fungus with suitable split-marker constructs. The mutant strains, together with the wild type strain, were used in growth studies as well as pathogenicity assays on Pinus patula seedlings. Results showed that the knockout mutant strain produced significantly smaller lesions compared to the complementation mutant and wild type strains. Growth studies also showed significantly smaller colonies and delayed conidial germination in the knockout mutant strain compared to the complement mutant and wild type strains. Interestingly, the knockout mutant strain produced more macroconidia than the wild type strain. Collectively, these results showed that Ras2 plays an important role in both growth and pathogenicity of F. circinatum. Future studies will seek to determine the pathway(s) through which Ras2 controls these traits in F. circinatum.
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14
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Abstract
This introductory chapter describes the life cycle of Magnaporthe oryzae, the causal agent of rice blast disease. During plant infection, M. oryzae forms a specialized infection structure called an appressorium, which generates enormous turgor, applied as a mechanical force to breach the rice cuticle. Appressoria form in response to physical cues from the hydrophobic rice leaf cuticle and nutrient availability. The signaling pathways involved in perception of surface signals are described and the mechanism by which appressoria function is also introduced. Re-polarization of the appressorium requires a septin complex to organize a toroidal F-actin network at the base of the cell. Septin aggregation requires a turgor-dependent sensor kinase, Sln1, necessary for re-polarization of the appressorium and development of a rigid penetration hypha to rupture the leaf cuticle. Once inside the plant, the fungus undergoes secretion of a large set of effector proteins, many of which are directed into plant cells using a specific secretory pathway. Here they suppress plant immunity, but can also be perceived by rice immune receptors, triggering resistances. M. oryzae then manipulates pit field sites, containing plasmodesmata, to facilitate rapid spread from cell to cell in plant tissue, leading to disease symptom development.
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15
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Qu Y, Wang J, Huang P, Liu X, Lu J, Lin FC. PoRal2 Is Involved in Appressorium Formation and Virulence via Pmk1 MAPK Pathways in the Rice Blast Fungus Pyricularia oryzae. FRONTIERS IN PLANT SCIENCE 2021; 12:702368. [PMID: 34589096 PMCID: PMC8473790 DOI: 10.3389/fpls.2021.702368] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/17/2021] [Indexed: 05/07/2023]
Abstract
Pyricularia oryzae is an important plant pathogenic fungus that can severely damage rice and wheat crops, leading to significant reductions in crop productivity. To penetrate into and invade tissues of its plant host, this fungus relies on an invasive structure known as an appressorium. Appressorium formation is rigorously regulated by the cAMP-PKA and Pmk1 MAPK pathways. Here, we identified PoRal2, a homologous protein of Schizosaccharomyces pombe Ral2, and characterized its roles in fungal development and virulence in P. oryzae. PoRal2 contains N-terminal kelch repeats and C-terminal BTB domains. PoRal2 is involved in sporulation, aerial hypha and conidiophore differentiation, appressorium formation, plant penetration, and virulence. During appressorium formation, ∆Poral2 mutants generate appressoria with long germ tubes on hydrophobic surfaces. ∆Poral2 mutants exhibited a defective response to exogenous cAMP and the activated RAS2 G18V on a hydrophilic surface, indicating impairment in the cAMP-PKA or Pmk1 MAPK signaling pathways. Deletion of PoRAL2 leads to lowered Pmk1 phosphorylation level in the mutant. Moreover, PoRal2 is found to interact with Scd1, Smo1, and Mst50, which are involved in activation of Pmk1. In addition, the expression levels of MPG1, WISH, and PDEH in the cAMP-PKA pathway, RAS2 in both the cAMP-PKA and Pmk1 MAPK pathways, and melanin biosynthesis genes (ALB1, BUF1, and RSY1) were significantly down-regulated in the ∆Poral2. Therefore, PoRal2 is involved in fungal development and virulence by its crosstalk in the cAMP-PKA and Pmk1 MAPK signaling pathways.
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Affiliation(s)
- Yingmin Qu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Jing Wang
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Pengyun Huang
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Xiaohong Liu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Jianping Lu
- College of Life Sciences, Zhejiang University, Hangzhou, China
- Jianping Lu,
| | - Fu-Cheng Lin
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Biotechnology, Zhejiang University, Hangzhou, China
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- *Correspondence: Fu-Cheng Lin,
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16
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Chen A, Ju Z, Wang J, Wang J, Wang H, Wu J, Yin Y, Zhao Y, Ma Z, Chen Y. The RasGEF FgCdc25 regulates fungal development and virulence in Fusarium graminearum via cAMP and MAPK signalling pathways. Environ Microbiol 2020; 22:5109-5124. [PMID: 32537857 DOI: 10.1111/1462-2920.15129] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 06/11/2020] [Accepted: 06/12/2020] [Indexed: 11/29/2022]
Abstract
Ras GTPases act as molecular switches to control various cellular processes by coupling integrated signals in eukaryotes. Activities of Ras GTPases are triggered by Ras GTPase guanine nucleotide exchange factors (RasGEFs) in general, whereas the role of RasGEF in plant pathogenic fungi is largely unknown. In this study, we characterized the only RasGEF protein in Fusarium graminearum, FgCdc25, by combining genetic, cytological and phenotypic strategies. FgCdc25 directly interacted with RasGTPase FgRas2, but not FgRas1, to regulate growth and sexual reproduction. Mutation of the FgCDC25 gene resulted in decreased toxisome formation and deoxynivalenol (DON) production, which was largely depended on cAMP signalling. In addition, FgCdc25 indirectly interacted with FgSte11 in FgSte11-Ste7-Gpmk1 cascade, and the ΔFgcdc25 strain totally abolished the formation of infection structures and was nonpathogenic in planta, which was partially recovered by addition of exogenous cAMP. In contrast, FgCdc25 directly interplayed with FgBck1 in FgBck1-MKK1-Mgv1 cascade to negatively control cell wall integrity. Collectively, these results suggest that FgCdc25 modulates cAMP and MAPK signalling pathways and further regulates fungal development, DON production and plant infection in F. graminearum.
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Affiliation(s)
- Ahai Chen
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Zhenzhen Ju
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Jinli Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Jing Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Hongkai Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Jiayu Wu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Yanni Yin
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
| | - Yun Chen
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
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17
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Yan Y, Tang J, Yuan Q, Gu Q, Liu H, Huang J, Hsiang T, Zheng L. ChCDC25 Regulates Infection-Related Morphogenesis and Pathogenicity of the Crucifer Anthracnose Fungus Colletotrichum higginsianum. Front Microbiol 2020; 11:763. [PMID: 32457707 PMCID: PMC7227425 DOI: 10.3389/fmicb.2020.00763] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 03/30/2020] [Indexed: 12/12/2022] Open
Abstract
The fungal pathogen, Colletotrichum higginsianum, causes a disease called anthracnose on various cruciferous plants. Here, we characterized a Saccharomyces cerevisiae CDC25 ortholog in C. higginsianum, named ChCDC25 (CH063_04363). The ChCDC25 deletion mutants were defective in mycelial growth, conidiation, conidial germination, appressorial formation, and invasive hyphal growth on Arabidopsis leaves, resulting in loss of virulence. Furthermore, deletion of ChCDC25 led to increased sensitivity to cell wall stress and resulted in resistance to osmotic stress. Exogenous cyclic adenosine monophosphate (cAMP) and IBMX treatments were able to induce appressorial formation in the ChCDC25 mutants, but abnormal germ tubes were still formed. The results implied that ChCDC25 is involved in pathogenicity by regulation of cAMP signaling pathways in C. higginsianum. More importantly, we found that ChCDC25 may interact with Ras2 and affects Ras2 protein abundance in C. higginsianum. Taken together, ChCDC25 regulates infection-related morphogenesis and pathogenicity of C. higginsianum. This is the first report to reveal functions of a CDC25 ortholog in a hemibiotrophic phytopathogen.
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Affiliation(s)
- Yaqin Yan
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Jintian Tang
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China.,Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, China
| | - Qinfeng Yuan
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Qiongnan Gu
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Hao Liu
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Junbin Huang
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
| | - Lu Zheng
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
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18
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Threonine synthase CoTHR4 is involved in infection-related morphogenesis during the pre-penetration stage in Colletotrichum orbiculare. Microb Pathog 2019; 137:103746. [DOI: 10.1016/j.micpath.2019.103746] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/08/2019] [Accepted: 09/11/2019] [Indexed: 12/13/2022]
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Aboelfotoh Hendy A, Xing J, Chen X, Chen X. The farnesyltransferase β-subunit RAM1 regulates localization of RAS proteins and appressorium-mediated infection in Magnaporthe oryzae. MOLECULAR PLANT PATHOLOGY 2019; 20:1264-1278. [PMID: 31250536 PMCID: PMC6715606 DOI: 10.1111/mpp.12838] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Post-translational farnesylation can regulate subcellular localization and protein-protein interaction in eukaryotes. The function of farnesylation is not well identified in plant pathogenic fungi, particularly during the process of fungal infection. Here, through functional analyses of the farnesyltransferase β-subunit gene, RAM1, we examine the importance of protein farnesylation in the rice blast fungus Magnaporthe oryzae. Targeted disruption of RAM1 resulted in the reduction of hyphal growth and sporulation, and an increase in the sensitivity to various stresses. Importantly, loss of RAM1 also led to the attenuation of virulence on the plant host, characterized by decreased appressorium formation and invasive growth. Interestingly, the defect in appressoria formation of the Δram1 mutant can be recovered by adding exogenous cAMP and IBMX, suggesting that RAM1 functions upstream of the cAMP signalling pathway. We found that two Ras GTPases, RAS1 and RAS2, can interact with Ram1, and their plasma membrane localization was regulated by Ram1 through their C-terminal farnesylation sites. Adding a farnesyltransferase inhibitor Tipifarnib can result in similar defects as in Δram1 mutant, including decreased appressorium formation and invasive growth, as well as mislocalized RAS proteins. Our findings indicate that protein farnesylation regulates the RAS protein-mediated signaling pathways required for appressorium formation and host infection, and suggest that abolishing farnesyltransferase could be an effective strategy for disease control.
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Affiliation(s)
- Ahmed Aboelfotoh Hendy
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhan430070China
- Department of Agricultural Botany, Faculty of Agriculture (Saba Basha)Alexandria UniversityAlexandria21531Egypt
| | - Junjie Xing
- State Key Laboratory of Hybrid RiceHunan Hybrid Rice Research CenterChangsha410125China
| | - Xiaoyang Chen
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhan430070China
| | - Xiao‐Lin Chen
- The Provincial Key Lab of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhan430070China
- State Key Laboratory of Hybrid RiceHunan Hybrid Rice Research CenterChangsha410125China
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20
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Zhu W, Xu X, Peng F, Yan DZ, Zhang S, Xu R, Wu J, Li X, Wei W, Chen W. The cyclase-associated protein ChCAP is important for regulation of hyphal growth, appressorial development, penetration, pathogenicity, conidiation, intracellular cAMP level, and stress tolerance in Colletotrichum higginsianum. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 283:1-10. [PMID: 31128679 DOI: 10.1016/j.plantsci.2019.02.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/20/2019] [Accepted: 02/22/2019] [Indexed: 06/09/2023]
Abstract
Colletotrichum higginsianum causes anthracnose disease in a wide range of cruciferous crops and has been used as a model system to study plant-pathogen interactions and pathogenicity of hemibiotrophic plant pathogens. Conidiation, hyphae growth, appressorial development and appressorial penetration are significant steps during the infection process of C. higginsianum. However, the mechanisms of these important steps during infection remain incompletely understood. To further investigate the mechanisms of the plant-C. higginsianum interactions during infection progress, we characterized Cyclase-Associated Protein (ChCAP) gene. Deletion of the ChCAP gene resulted in reduction in conidiation and hyphal growth rate. The pathogenicity of ΔChCAP mutants was significantly reduced with much smaller lesion on the infected leaves compared to that of wild type strain with typically water-soaked and dark necrotic lesions on Arabidopsis leaves. Further study demonstrated that the appressorial formation rate, turgor pressure, penetration ability and switch from biotrophic to necrotrophic phases decreased obviously in ΔChCAP mutants, indicating that the attenuated pathogenicity of ΔChCAP mutants was due to these defective phenotypes. In addition, the ΔChCAP mutants sectored on PDA with abnormal, dark color, vesicle-like colony morphology and hyphae tip. Moreover, the ΔChCAP mutants had a reduced intracellular cAMP levels and exogenous cAMP can partially rescue the defects of ΔChCAP mutants in appressorial formation and penetration rate, but not in colony morphology, conidial shape and virulence, indicating that ChCAP is a key component in cAMP signaling pathway and likely play other roles in biology of C. higginsianum. In summary, our findings support the role of ChCAP in regulating conidiation, intracellular cAMP level, hyphal growth, appressorial formation, penetration ability and pathogenicity of this hemibiotrophic fungus.
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Affiliation(s)
- Wenjun Zhu
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, People's Republic of China
| | - Xiaowen Xu
- Hubei Academy of Forestry, Wuhan 430075, People's Republic of China
| | - Fang Peng
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, People's Republic of China
| | - Da-Zhong Yan
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, People's Republic of China
| | - Shaopeng Zhang
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, People's Republic of China
| | - Ran Xu
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, People's Republic of China
| | - Jing Wu
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, People's Republic of China
| | - Xin Li
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, People's Republic of China
| | - Wei Wei
- Department of Plant Pathology, Washington State University, United States Department of Agriculture-Agricultural Research Service, Washington State University, Pullman 99164, USA.
| | - Weidong Chen
- Department of Plant Pathology, Washington State University, United States Department of Agriculture-Agricultural Research Service, Washington State University, Pullman 99164, USA.
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Conidial Morphogenesis and Septin-Mediated Plant Infection Require Smo1, a Ras GTPase-Activating Protein in Magnaporthe oryzae. Genetics 2018; 211:151-167. [PMID: 30446520 PMCID: PMC6325701 DOI: 10.1534/genetics.118.301490] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/12/2018] [Indexed: 01/21/2023] Open
Abstract
The pathogenic life cycle of the rice blast fungus Magnaporthe oryzae involves a series of morphogenetic changes, essential for its ability to cause disease. The smo mutation was identified > 25 years ago, and affects the shape and development of diverse cell types in M. oryzae, including conidia, appressoria, and asci. All attempts to clone the SMO1 gene by map-based cloning or complementation have failed over many years. Here, we report the identification of SMO1 by a combination of bulk segregant analysis and comparative genome analysis. SMO1 encodes a GTPase-activating protein, which regulates Ras signaling during infection-related development. Targeted deletion of SMO1 results in abnormal, nonadherent conidia, impaired in their production of spore tip mucilage. Smo1 mutants also develop smaller appressoria, with a severely reduced capacity to infect rice plants. SMO1 is necessary for the organization of microtubules and for septin-dependent remodeling of the F-actin cytoskeleton at the appressorium pore. Smo1 physically interacts with components of the Ras2 signaling complex, and a range of other signaling and cytoskeletal components, including the four core septins. SMO1 is therefore necessary for the regulation of RAS activation required for conidial morphogenesis and septin-mediated plant infection.
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Yan Y, Yuan Q, Tang J, Huang J, Hsiang T, Wei Y, Zheng L. Colletotrichum higginsianum as a Model for Understanding Host⁻Pathogen Interactions: A Review. Int J Mol Sci 2018; 19:E2142. [PMID: 30041456 PMCID: PMC6073530 DOI: 10.3390/ijms19072142] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 07/18/2018] [Accepted: 07/18/2018] [Indexed: 11/16/2022] Open
Abstract
Colletotrichum higginsianum is a hemibiotrophic ascomycetous fungus that causes economically important anthracnose diseases on numerous monocot and dicot crops worldwide. As a model pathosystem, the Colletotrichum⁻Arabidopsis interaction has the significant advantage that both organisms can be manipulated genetically. The goal of this review is to provide an overview of the system and to point out recent significant studies that update our understanding of the pathogenesis of C. higginsianum and resistance mechanisms of Arabidopsis against this hemibiotrophic fungus. The genome sequence of C. higginsianum has provided insights into how genome structure and pathogen genetic variability has been shaped by transposable elements, and allows systematic approaches to longstanding areas of investigation, including infection structure differentiation and fungal⁻plant interactions. The Arabidopsis-Colletotrichum pathosystem provides an integrated system, with extensive information on the host plant and availability of genomes for both partners, to illustrate many of the important concepts governing fungal⁻plant interactions, and to serve as an excellent starting point for broad perspectives into issues in plant pathology.
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Affiliation(s)
- Yaqin Yan
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
| | - Qinfeng Yuan
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
| | - Jintian Tang
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
| | - Junbin Huang
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Yangdou Wei
- Department of Biology, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada.
| | - Lu Zheng
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
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Affiliation(s)
- Cong Jiang
- NWAFU-Purdue Joint Research Center, College of Plant Protection, State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Shaanxi, P. R. China
- Dept. of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
| | - Xue Zhang
- Dept. of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
| | - Huiquan Liu
- NWAFU-Purdue Joint Research Center, College of Plant Protection, State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Shaanxi, P. R. China
| | - Jin-Rong Xu
- Dept. of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail:
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Rise of a Cereal Killer: The Biology of Magnaporthe oryzae Biotrophic Growth. Trends Microbiol 2018; 26:582-597. [PMID: 29395728 DOI: 10.1016/j.tim.2017.12.007] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 12/16/2017] [Accepted: 12/20/2017] [Indexed: 01/24/2023]
Abstract
The rice blast fungus, Magnaporthe oryzae, causes one of the most destructive diseases of cultivated rice in the world. Infections caused by this recalcitrant pathogen lead to the annual destruction of approximately 10-30% of the rice harvested globally. The fungus undergoes extensive developmental changes to be able to break into plant cells, build elaborate infection structures, and proliferate inside host cells without causing visible disease symptoms. From a molecular standpoint, we are still in the infancy of understanding how M. oryzae manipulates the host during this complex multifaceted infection. Here, we describe recent advances in our understanding of the cell biology of M. oryzae biotrophic interaction and key molecular factors required for the disease establishment in rice cells.
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Li Y, Zhang X, Hu S, Liu H, Xu JR. PKA activity is essential for relieving the suppression of hyphal growth and appressorium formation by MoSfl1 in Magnaporthe oryzae. PLoS Genet 2017; 13:e1006954. [PMID: 28806765 PMCID: PMC5570492 DOI: 10.1371/journal.pgen.1006954] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/24/2017] [Accepted: 08/04/2017] [Indexed: 11/29/2022] Open
Abstract
In the rice blast fungus Magnaporthe oryzae, the cAMP-PKA pathway regulates surface recognition, appressorium turgor generation, and invasive growth. However, deletion of CPKA failed to block appressorium formation and responses to exogenous cAMP. In this study, we generated and characterized the cpk2 and cpkA cpk2 mutants and spontaneous suppressors of cpkA cpk2 in M. oryzae. Our results demonstrate that CPKA and CPK2 have specific and overlapping functions, and PKA activity is essential for appressorium formation and plant infection. Unlike the single mutants, the cpkA cpk2 mutant was significantly reduced in growth and rarely produced conidia. It failed to form appressoria although the intracellular cAMP level and phosphorylation of Pmk1 MAP kinase were increased. The double mutant also was defective in plant penetration and Mps1 activation. Interestingly, it often produced fast-growing spontaneous suppressors that formed appressoria but were still non-pathogenic. Two suppressor strains of cpkA cpk2 had deletion and insertion mutations in the MoSFL1 transcription factor gene. Deletion of MoSFL1 or its C-terminal 93-aa (MoSFL1ΔCT) was confirmed to suppress the defects of cpkA cpk2 in hyphal growth but not appressorium formation or pathogenesis. We also isolated 30 spontaneous suppressors of the cpkA cpk2 mutant in Fusarium graminearum and identified mutations in 29 of them in FgSFL1. Affinity purification and co-IP assays showed that this C-terminal region of MoSfl1 was essential for its interaction with the conserved Cyc8-Tup1 transcriptional co-repressor, which was reduced by cAMP treatment. Furthermore, the S211D mutation at the conserved PKA-phosphorylation site in MoSFL1 partially suppressed the defects of cpkA cpk2. Overall, our results indicate that PKA activity is essential for appressorium formation and proper activation of Pmk1 or Mps1 in M. oryzae, and phosphorylation of MoSfl1 by PKA relieves its interaction with the Cyc8-Tup1 co-repressor and suppression of genes important for hyphal growth. The cAMP-PKA signaling pathway plays a critical role in regulating various cellular processes in eukaryotic cells in response to extracellular cues. In the rice blast fungus, this important pathway is involved in surface recognition, appressorium morphogenesis, and infection. However, the exact role of PKA is not clear due to the functional redundancy of two PKA catalytic subunits CPKA and CPK2. To further characterize their functions in growth and pathogenesis, in this study we generated and characterized the cpkA cpk2 double mutant and its suppressor strains. Unlike the single mutants, cpkA cpk2 mutant had severe defects in growth and conidiation and was defective in appressorium formation and plant infection. Interestingly, the double mutant was unstable and produced fast-growing suppressors. In two suppressor strains, mutations were identified in a transcription factor gene orthologous to SFL1, a downstream target of PKA in yeast. Deletion of the entire or C-terminal 93 residues of MoSFL1 could suppress the growth defect of cpkA cpk2. Furthermore, the terminal region of MoSfl1 was found to be essential for its interaction with the MoCyc8 co-repressor, which may be negatively regulated by PKA. Therefore, loss-of-function mutations in MoSFL1 can bypass PKA activity to suppress the growth defect of cpkA cpk2.
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Affiliation(s)
- Yang Li
- Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
| | - Xue Zhang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
| | - Shuai Hu
- Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Huiquan Liu
- Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Jin-Rong Xu
- Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail:
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Zhu W, Zhou M, Xiong Z, Peng F, Wei W. The cAMP-PKA Signaling Pathway Regulates Pathogenicity, Hyphal Growth, Appressorial Formation, Conidiation, and Stress Tolerance in Colletotrichum higginsianum. Front Microbiol 2017; 8:1416. [PMID: 28791004 PMCID: PMC5524780 DOI: 10.3389/fmicb.2017.01416] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/12/2017] [Indexed: 11/13/2022] Open
Abstract
Colletotrichum higginsianum is an economically important pathogen that causes anthracnose disease in a wide range of cruciferous crops. Understanding the mechanisms of the cruciferous plant–C. higginsianum interactions will be important in facilitating efficient control of anthracnose diseases. The cAMP-PKA signaling pathway plays important roles in diverse physiological processes of multiple pathogens. C. higginsianum contains two genes, ChPKA1 and ChPKA2, that encode the catalytic subunits of cyclic AMP (cAMP)-dependent protein kinase A (PKA). To analyze the role of cAMP signaling pathway in pathogenicity and development in C. higginsianum, we characterized ChPKA1 and ChPKA2 genes, and adenylate cyclase (ChAC) gene. The ChPKA1 and ChAC deletion mutants were unable to cause disease and significantly reduced in hyphal growth, tolerance to cell wall inhibitors, conidiation, and appressorial formation with abnormal germ tubes, but they had an increased tolerance to elevated temperatures and exogenous H2O2. In contrast, the ChPKA2 mutant had no detectable alteration of phenotypes, suggesting that ChPKA1 contributes mainly to PKA activities in C. higginsianum. Moreover, we failed to generate ΔChPKA1ChPKA2 double mutant, indicating that deletion of both PKA catalytic subunits is lethal in C. higginsianum and the two catalytic subunits possibly have overlapping functions. These results indicated that ChPKA1 is the major PKA catalytic subunit in cAMP-PKA signaling pathway and plays significant roles in hyphal growth, pathogenicity, appressorial formation, conidiation, and stress tolerance in C. higginsianum.
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Affiliation(s)
- Wenjun Zhu
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic UniversityWuhan, China
| | - Man Zhou
- Institute for Interdisciplinary Research, Jianghan UniversityWuhan, China
| | - Zeyang Xiong
- Institute for Interdisciplinary Research, Jianghan UniversityWuhan, China
| | - Fang Peng
- College of Biology and Pharmaceutical Engineering, Wuhan Polytechnic UniversityWuhan, China
| | - Wei Wei
- Institute for Interdisciplinary Research, Jianghan UniversityWuhan, China
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Li G, Zhang X, Tian H, Choi YE, Tao WA, Xu JR. MST50 is involved in multiple MAP kinase signaling pathways in Magnaporthe oryzae. Environ Microbiol 2017; 19:1959-1974. [PMID: 28244240 DOI: 10.1111/1462-2920.13710] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 02/17/2017] [Accepted: 02/19/2017] [Indexed: 12/31/2022]
Abstract
Appressorium formation plays a critical role in Magnaporthe oryzae. Mst50 is an adapter protein of the Mst11-Mst7-Pmk1 cascade that is essential for appressorium formation. To further characterize its functions, affinity purification was used to identify Mst50-interacting proteins (MIPs) in this study. Two of the MIPs are Mst11 and Mst7 that are known to interact with Mst50 for Pmk1 activation. Surprisingly, two other MIPs are Mck1 and Mkk2 that are the upstream kinases of the Mps1 pathway. Domain deletion analysis showed that the sterile alpha-motif of Mst50 but not the Ras-association domain was important for its interaction with Mck1 and responses to cell wall and oxidative stresses. The mst50 mutant was reduced in Mps1 activation under stress conditions. MIP11 encodes a RACK1 protein that also interacted with Mck1. Deletion of MIP11 resulted in defects in cell wall integrity, Mps1 phosphorylation and plant infection. Furthermore, Mst50 interacted with histidine kinase Hik1, and the mst50 mutant was reduced in Osm1 phosphorylation. These results indicated that Mst50 is involved in all three MAPK pathways in M. oryzae although its functions differ in each pathway. Several MIPs are conserved hypothetical proteins and may be involved in responses to various signals and crosstalk among signaling pathways.
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Affiliation(s)
- Guotian Li
- Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China.,Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Xue Zhang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Huan Tian
- Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yoon-E Choi
- Division of Environmental Science and Ecological Engineering, College of Life Sciences and Biotechnology, Korea University, Seoul, 136-713, Republic of Korea
| | - W Andy Tao
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Jin-Rong Xu
- Purdue-NWAFU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China.,Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
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28
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Gu Q, Chen M, Huang J, Wei Y, Hsiang T, Zheng L. Multifaceted Roles of the Ras Guanine-Nucleotide Exchange Factor ChRgf in Development, Pathogenesis, and Stress Responses of Colletotrichum higginsianum. PHYTOPATHOLOGY 2017; 107:433-443. [PMID: 28026997 DOI: 10.1094/phyto-03-16-0137-r] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The infection process of Colletotrichum higginsianum, which causes a disease of crucifers, involves several key steps: conidial germination, appressorial formation, appressorial penetration, and invasive growth in host tissues. In this study, the ChRgf gene encoding a Ras guanine-nucleotide exchange factor protein was identified by screening T-DNA insertion mutants generated from Agrobacterium tumefaciens-mediated transformation that were unable to cause disease on the host Arabidopsis thaliana. Targeted gene deletion of ChRgf resulted in a null mutant (ΔChrgf-42) with defects in vegetative growth, hyphal morphology, and conidiation, and poor surface attachment and low germination on hydrophobic surfaces; however, there were no apparent differences in appressorial turgor pressure between the wild type and the mutant. The conidia of the mutant were unable to geminate on attached Arabidopsis leaves and did not cause any disease symptoms. Intracellular cyclic adenosine monophosphate levels in the ΔChrgf mutant were lower than that of the wild type. Our results suggest that ChRgf is a key regulator in response to salt and osmotic stresses in C. higginsianum, and indicate that it is involved in fungal pathogenicity. This gene seems to act as an important modulator upstream of several distinct signaling pathways that are involved in regulating vegetative growth, conidiation, infection-related structure development, and stress responses of C. higginsianum.
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Affiliation(s)
- Qiongnan Gu
- First, second, and sixth authors: The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, Hubei, China; first and fourth authors: Department of Biology, University of Saskatchewan, Saskatoon S7N 5E2, Canada; and fifth author: School of Environmental Sciences, University of Guelph, Guelph N1G 2W1, Canada
| | - Meijuan Chen
- First, second, and sixth authors: The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, Hubei, China; first and fourth authors: Department of Biology, University of Saskatchewan, Saskatoon S7N 5E2, Canada; and fifth author: School of Environmental Sciences, University of Guelph, Guelph N1G 2W1, Canada
| | - Junbin Huang
- First, second, and sixth authors: The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, Hubei, China; first and fourth authors: Department of Biology, University of Saskatchewan, Saskatoon S7N 5E2, Canada; and fifth author: School of Environmental Sciences, University of Guelph, Guelph N1G 2W1, Canada
| | - Yangdou Wei
- First, second, and sixth authors: The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, Hubei, China; first and fourth authors: Department of Biology, University of Saskatchewan, Saskatoon S7N 5E2, Canada; and fifth author: School of Environmental Sciences, University of Guelph, Guelph N1G 2W1, Canada
| | - Tom Hsiang
- First, second, and sixth authors: The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, Hubei, China; first and fourth authors: Department of Biology, University of Saskatchewan, Saskatoon S7N 5E2, Canada; and fifth author: School of Environmental Sciences, University of Guelph, Guelph N1G 2W1, Canada
| | - Lu Zheng
- First, second, and sixth authors: The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, Hubei, China; first and fourth authors: Department of Biology, University of Saskatchewan, Saskatoon S7N 5E2, Canada; and fifth author: School of Environmental Sciences, University of Guelph, Guelph N1G 2W1, Canada
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29
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Shi HB, Chen GQ, Chen YP, Dong B, Lu JP, Liu XH, Lin FC. MoRad6-mediated ubiquitination pathways are essential for development and pathogenicity in Magnaporthe oryzae. Environ Microbiol 2016; 18:4170-4187. [PMID: 27581713 DOI: 10.1111/1462-2920.13515] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Accepted: 08/28/2016] [Indexed: 01/19/2023]
Abstract
The ubiquitin system modulates protein functions through targeting substrates for ubiquitination. Here, E2 conjugating enzyme MoRad6-related ubiquitination pathways are identified and analyzed in Magnaporthe oryzae, the causal agent of rice blast disease. Disruption of MoRad6 leads to severe defects in growth, sporulation, conidial germination, appressorium formation, and plant infection. To depict the functions of MoRad6, three putative ubiquitin ligases, MoRad18, MoBre1 and MoUbr1, are also characterized. Deletion of MoRad18 causes minor phenotypic changes, while MoBre1 is required for growth, conidiation and pathogenicity in M. oryzae. Defects in ΔMobre1 likely resulted from the reduction in di- and tri-methylation level of Histone 3 lysine 4 (H3K4). Notably, MoUbr1 is crucial for conidial adhesion and germination, possibly by degrading components of cAMP/PKA and mitogen-activated protein kinase (MAPK) Pmk1 signaling pathways via the N-end rule pathway. Germination failure of ΔMoubr1 conidia could be rescued by elevation of cAMP level or enhanced Pmk1 phosphorylation resulting from further deletion of MoIra1, the M. oryzae homolog of yeast Ira1/2. These reveal vital effects of cAMP/PKA and MAPK Pmk1 signaling on conidial germination in M. oryzae. Altogether, our results suggest that MoRad6-mediated ubiquitination pathways are essential for the infection-related development and pathogenicity of M. oryzae.
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Affiliation(s)
- Huan-Bin Shi
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou, 310058, China
| | - Guo-Qing Chen
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006, China
| | - Ya-Ping Chen
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou, 310058, China
| | - Bo Dong
- Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Science, Hangzhou, 310021, China
| | - Jian-Ping Lu
- College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Xiao-Hong Liu
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou, 310058, China
| | - Fu-Cheng Lin
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou, 310058, China
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30
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Kou Y, Naqvi NI. Surface sensing and signaling networks in plant pathogenic fungi. Semin Cell Dev Biol 2016; 57:84-92. [DOI: 10.1016/j.semcdb.2016.04.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/21/2016] [Accepted: 04/26/2016] [Indexed: 11/29/2022]
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31
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Martin-Urdiroz M, Oses-Ruiz M, Ryder LS, Talbot NJ. Investigating the biology of plant infection by the rice blast fungus Magnaporthe oryzae. Fungal Genet Biol 2016; 90:61-68. [DOI: 10.1016/j.fgb.2015.12.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 12/13/2015] [Accepted: 12/14/2015] [Indexed: 10/22/2022]
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Ryder LS, Talbot NJ. Regulation of appressorium development in pathogenic fungi. CURRENT OPINION IN PLANT BIOLOGY 2015; 26:8-13. [PMID: 26043436 PMCID: PMC4781897 DOI: 10.1016/j.pbi.2015.05.013] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Revised: 04/29/2015] [Accepted: 05/13/2015] [Indexed: 05/20/2023]
Abstract
Many plant pathogenic fungi have the capacity to breach the intact cuticles of their plant hosts using specialised infection cells called appressoria. These cells exert physical force to rupture the plant surface, or deploy enzymes in a focused way to digest the cuticle and plant cell wall. They also provide the means by which focal secretion of effectors occurs at the point of plant infection. Development of appressoria is linked to re-modelling of the actin cytoskeleton, mediated by septin GTPases, and rapid cell wall differentiation. These processes are regulated by perception of plant cell surface components, and starvation stress, but also linked to cell cycle checkpoints that control the overall progression of infection-related development.
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Affiliation(s)
- Lauren S Ryder
- School of Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
| | - Nicholas J Talbot
- School of Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom.
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33
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Qi L, Kim Y, Jiang C, Li Y, Peng Y, Xu JR. Activation of Mst11 and Feedback Inhibition of Germ Tube Growth in Magnaporthe oryzae. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 28:881-91. [PMID: 26057388 DOI: 10.1094/mpmi-12-14-0391-r] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Appressorium formation and invasive growth are two important steps in the infection cycle of Magnaporthe oryzae that are regulated by the Mst11-Mst7-Pmk1 mitogen-activated protein kinase (MAPK) pathway. However, the molecular mechanism involved in the activation of Mst11 MAPK kinase kinase is not clear in the rice blast fungus. In this study, we functionally characterized the regulatory region of Mst11 and its self-inhibitory binding. Deletion of the middle region of Mst11, which contains the Ras-association (RA) domain and two conserved phosphorylation sites (S453 and S458), blocked Pmk1 activation and appressorium formation. However, the MST11(ΔRA) transformant MRD-2 still formed appressoria, although it was reduced in virulence. Interestingly, over 50% of its germ tubes branched and formed two appressoria by 48 h, which was suppressed by treatments with exogenous cAMP. The G18V dominant active mutation enhanced the interaction of Ras2 with Mst11, suggesting that Mst11 has stronger interactions with the activated Ras2. Furthermore, deletion and site-directed mutagenesis analyses indicated that phosphorylation at S453 and S458 of Mst11 is important for appressorium formation and required for the activation of Pmk1. We also showed that the N-terminal region of Mst11 directly interacted with its kinase domain, and the S789G mutation reduced their interactions. Expression of the MST11(S789G) allele rescued the defect of the mst11 mutant in plant infection and resulted in the formation of appressoria on hydrophilic surfaces, suggesting the gain-of-function effect of the S789G mutation. Overall, our results indicate that the interaction of Mst11 with activated Ras2 and phosphorylation of S453 and S458 play regulatory roles in Mst11 activation and infection-related morphogenesis, possibly by relieving its self-inhibitory interaction between its N-terminal region and the C-terminal kinase domain. In addition, binding of Mst11 to Ras2 may be involved in the feedback inhibition of cAMP signaling and further differentiation of germ tubes after appressorium formation.
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Affiliation(s)
- Linlu Qi
- 1 MOA Key Laboratory of Plant Pathology, China Agricultural University, Beijing 100193, China
- 2 Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, U.S.A
| | - Yangseon Kim
- 2 Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, U.S.A
| | - Cong Jiang
- 2 Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, U.S.A
- 3 NWAFU-PU Joint Research Center, Northwestern A&F University, Yangling, Shaanxi 712100, China
| | - Yang Li
- 2 Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, U.S.A
| | - Youliang Peng
- 1 MOA Key Laboratory of Plant Pathology, China Agricultural University, Beijing 100193, China
| | - Jin-Rong Xu
- 2 Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, U.S.A
- 3 NWAFU-PU Joint Research Center, Northwestern A&F University, Yangling, Shaanxi 712100, China
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34
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Arkowitz RA, Bassilana M. Regulation of hyphal morphogenesis by Ras and Rho small GTPases. FUNGAL BIOL REV 2015. [DOI: 10.1016/j.fbr.2015.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Wang G, Li G, Zhang S, Jiang C, Qin J, Xu JR. Activation of the signalling mucin MoMsb2 and its functional relationship with Cbp1 in Magnaporthe oryzae. Environ Microbiol 2015; 17:2969-81. [PMID: 25808678 DOI: 10.1111/1462-2920.12847] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 03/10/2015] [Accepted: 03/12/2015] [Indexed: 11/27/2022]
Abstract
Various surface signals are recognized by Magnaporthe oryzae to activate the Pmk1 MAP kinase that is essential for appressorium formation and invasive growth. One of upstream sensors of the Pmk1 pathway is the MoMsb2 signalling mucin. However, the activation of MoMsb2 and its relationship with other sensors is not clear. In this study, we showed that the cleavage and transmembrane domains are essential for MoMsb2 functions. Cleavage of MoMsb2 was further confirmed by western blot analysis, and five putative cleavage sites were functionally characterized. Expression of the extracellular region alone partially rescued the defects of Momsb2 in appressorium formation and virulence. The cytoplasmic region of MoMsb2, although dispensable for appressorium formation, was more important for penetration and invasive growth. Interestingly, the Momsb2 cbp1 double mutant deleted of both mucin genes was blocked in Pmk1 activation. It failed to form appressoria on artificial surfaces and was non-pathogenic. In addition, we showed that MoMsb2 interacts with Ras2 but not with MoCdc42 in co-immunoprecipitation assays. Overall, results from this study indicated that the extracellular and cytoplasmic regions of MoMsb2 have distinct functions in appressorium formation, penetration and invasive growth, and MoMsb2 has overlapping functions with Cbp1 in recognizing environmental signals for Pmk1 activation.
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Affiliation(s)
- Guanghui Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China.,Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Guotian Li
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Shijie Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Cong Jiang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Jun Qin
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Jin-Rong Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China.,Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
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