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Jia W, Yu H, Fan J, Zhang J, Su L, Li D, Pan H, Zhang X. Crucial Roles of the High-Osmolarity Glycerol Pathway in the Antifungal Activity of Isothiocyanates against Cochliobolus heterostrophus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:15466-15475. [PMID: 37877171 DOI: 10.1021/acs.jafc.3c04853] [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: 10/26/2023]
Abstract
Isothiocyanates (ITCs) that are found in Brassicaceae exhibited obvious antifungal activity against Cochliobolus heterostrophus, which is the causal agent of southern corn leaf blight. However, the underlying antifungal mechanism of allyl-ITCs (A-ITCs) against C. heterostrophus remains largely unknown. Here, we used transcriptomic analysis to find that the high osmolarity pathway was upregulated significantly when treated with A-ITCs. To investigate the roles of the high osmolarity pathway in adaption to A-ITCs, we constructed Δssk2, Δpbs2, and Δhog1 mutant strains. Deletion of three genes (ChSSK2, ChPBS2, and ChHOG1) involved in the high osmolarity pathway resulted in significantly increased sensitivity of C. heterostrophus to ITCs. In addition, the phosphorylation level of ChHog1 was induced by A-ITC and was dependent on the presence of ChSsk2 and ChPbs2. Moreover, Δssk2, Δpbs2, and Δhog1 mutants exhibited a dramatically decreased virulence on maize leaves. Our findings demonstrated that the high osmolarity pathway played a positive role in ITC tolerance and virulence, which may provide novel insights into developing ITCs as a new fungicide against C. heterostrophus.
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Affiliation(s)
- Wantong Jia
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Huilin Yu
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Jinyu Fan
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Jiyue Zhang
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Longhao Su
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Dan Li
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Hongyu Pan
- College of Plant Science, Jilin University, Changchun 130062, China
| | - Xianghui Zhang
- College of Plant Science, Jilin University, Changchun 130062, China
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Zhuo R, Chen Y, Xing M, Zhang Z, Tian S, Li B. Ena Proteins Respond to PacC-Mediated pH Signaling Pathway and Play a Crucial Role in Patulin Biosynthesis. J Fungi (Basel) 2023; 9:806. [PMID: 37623577 PMCID: PMC10455529 DOI: 10.3390/jof9080806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/28/2023] [Accepted: 07/28/2023] [Indexed: 08/26/2023] Open
Abstract
Penicillium expansum is a main producer of patulin that causes severe postharvest decay and food safety issues in the fruit industry. Development, pathogenicity, and patulin production of P. expansum are strongly influenced by the PacC-pH signaling pathway. Global transcription factor PacC regulates various fungal biological processes through a complicated molecular network. In the present study, three Ena family genes (PeEnas), PeEnaA, PeEnaB, and PeEnaC, as important downstream targets of PePacC, were identified in P. expansum. Deletion of PeEnaA, PeEnaB, and PeEnaC showed little effect on mycelial growth under alkaline or high salinity conditions, but double and triple deletion of these genes impaired the virulence of P. expansum on apple fruit. Notably, patulin biosynthesis of P. expansum was distinctly inhibited in the deletion mutants of PeEnas. PeEnas regulated expressions of the patulin gene cluster, AP1, CreA, Sge1, and Hog1 at the transcriptional level and played roles in maintaining membrane potential. Overexpression of PeEnaC in ΔPePacC restored the patulin production defect of ΔPePacC. Our results indicated that, as downstream targets of PePacC, the PeEna family proteins play a crucial role in patulin biosynthesis in P. expansum.
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Affiliation(s)
- Ruiling Zhuo
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yong Chen
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
| | - Mengyang Xing
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhanquan Zhang
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
| | - Shiping Tian
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Boqiang Li
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- China National Botanical Garden, Beijing 100093, China
- Key Laboratory of Post-Harvest Handling of Fruits, Ministry of Agriculture, Beijing 100093, China
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Qin X, Tian C, Meng F. Comparative Transcriptome Analysis Reveals the Effect of the DHN Melanin Biosynthesis Pathway on the Appressorium Turgor Pressure of the Poplar Anthracnose-Causing Fungus Colletotrichum gloeosporioides. Int J Mol Sci 2023; 24:ijms24087411. [PMID: 37108573 PMCID: PMC10138971 DOI: 10.3390/ijms24087411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/13/2023] [Accepted: 04/16/2023] [Indexed: 04/29/2023] Open
Abstract
Anthracnose of poplar caused by Colletotrichum gloeosporioides is a leaf disease that seriously affects poplar growth. The pathogen invades the host in the form of adherent cells, which generate turgor pressure through the metabolism of intracellular substances prior to penetrating the epidermis of poplar leaves. In this study, the expansion-related pressure of the mature appressorium of the wild-type C. gloeosporioides was approximately 13.02 ± 1.54 MPa at 12 h, whereas it was 7.34 ± 1.23 MPa and 9.34 ± 2.22 MPa in the melanin synthesis-related gene knockout mutants ΔCgCmr1 and ΔCgPks1, respectively. The CgCmr1 and CgPks1 genes were highly expressed at 12 h in the wild-type control, implying that the DHN melanin biosynthesis pathway may play an important role in the mature appressorium stage. The transcriptome sequencing analysis indicated that the upregulated melanin biosynthesis genes in C. gloeosporioides, such as CgScd1, CgAyg1, CgThr1, CgThr2, and CgLac1, are involved in specific KEGG pathways (i.e., fatty acid biosynthesis, fatty acid metabolism, and biotin metabolism). Therefore, we speculate that the melanin synthesis-related genes and fatty acid metabolism pathway genes contribute to the regulation of the turgor pressure in the mature C. gloeosporioides appressorium, ultimately leading to the formation of infection pegs that enter plant tissues. These observations may reflect the co-evolution of C. gloeosporioides and its host.
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Affiliation(s)
- Xinyu Qin
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Fanli Meng
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing 100083, China
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Yu L, Wen D, Yang Y, Qiu X, Xiong D, Tian C. Comparative Transcriptomic Analysis of MAPK-Mediated Regulation of Pathogenicity, Stress Responses, and Development in Cytospora chrysosperma. PHYTOPATHOLOGY 2023; 113:239-251. [PMID: 36191174 DOI: 10.1094/phyto-04-22-0126-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Mitogen-activated protein kinase (MAPK) cascades are highly conserved signal transduction pathways that mediate cellular responses to various biotic and abiotic signals in plant-pathogenic fungi. Generally, there are three MAPKs in filamentous pathogenic fungi: Pmk1/Fus3/Kss1, Hog1, and Stl2. Our previous studies have shown that CcPmk1 is a core regulator of fungal pathogenicity in Cytospora chrysosperma, the causal agent of canker disease in a wide range of woody plants. Here, we identified and functionally characterized the other two MAPK genes (CcHog1 and CcSlt2) and then compared the transcriptional differences among these three MAPKs in C. chrysosperma. We found that the MAPKs shared convergent and distinct roles in fungal development, stress responses, and virulence. For example, CcHog1, CcSlt2, and CcPmk1 were all involved in conidiation and response to stresses, including hyperosmotic pressure, cell wall inhibition agents, and H2O2, but only CcPmk1 and CcSlt2 were required for hyphal growth and fungal pathogenicity. Transcriptomic analysis showed that numerous hyperosmosis- and cell wall-related genes significantly reduced their expression levels in ΔCcHog1 and ΔCcSlt2, respectively. Interestingly, RNA- and ribosome-related processes were significantly enriched in the upregulated genes of ΔCcSlt2, whereas they were significantly enriched in the downregulated genes of ΔCcPmk1. Moreover, two secondary metabolite gene clusters were significantly downregulated in ΔCcPmk1, ΔCcSlt2, and/or ΔCcHog1. Importantly, some virulence-associated genes were significantly downregulated in ΔCcPmk1 and/or ΔCcSlt2, such as candidate effector genes. Collectively, these results suggest that the similar and distinct phenotypes of each MAPK deletion mutant may result from the transcriptional regulation of a series of common or specific downstream genes, which provides a better understanding of the regulation network of MAPKs in C. chrysosperma.
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Affiliation(s)
- Lu Yu
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Dasen Wen
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Yuchen Yang
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Xiaolin Qiu
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Dianguang Xiong
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, 100083, China
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, 100083, China
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Zhang YZ, Li B, Pan YT, Fang YL, Li DW, Huang L. Protein Phosphatase CgPpz1 Regulates Potassium Uptake, Stress Responses, and Plant Infection in Colletotrichum gloeosporioides. PHYTOPATHOLOGY 2022; 112:820-829. [PMID: 34689611 DOI: 10.1094/phyto-02-21-0051-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Protein phosphatases play important roles in the regulation of various cellular processes in eukaryotes. The ascomycete Colletotrichum gloeosporioides is a causal agent of anthracnose disease on some important crops and trees. In this study, CgPPZ1, a protein phosphate gene and a homolog of yeast PPZ1, was identified in C. gloeosporioides. Targeted gene deletion showed that CgPpz1 was important for vegetative growth and asexual development, conidial germination, and plant infection. Cytological examinations revealed that CgPpz1 was localized to the cytoplasm. The ΔCgppz1 mutant was hypersensitive to osmotic stresses, cell wall stressors, and oxidative stressors. Taken together, our results indicated that CgPpz1 plays an important role in the fungal development and virulence of C. gloeosporioides and the multiple stress responses generated.
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Affiliation(s)
- Yun-Zhao Zhang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Bing Li
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, Henan 450001, China
| | - Yu-Ting Pan
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Yu-Lan Fang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - De-Wei Li
- The Connecticut Agricultural Experiment Station Valley Laboratory, Windsor, CT 06095, U.S.A
| | - Lin Huang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
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Jiang L, Zhang S, Su J, Peck SC, Luo L. Protein Kinase Signaling Pathways in Plant- Colletotrichum Interaction. FRONTIERS IN PLANT SCIENCE 2022; 12:829645. [PMID: 35126439 PMCID: PMC8811371 DOI: 10.3389/fpls.2021.829645] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
Anthracnose is a fungal disease caused by members of Colletotrichum that affect a wide range of crop plants. Strategies to improve crop resistance are needed to reduce the yield losses; and one strategy is to manipulate protein kinases that catalyze reversible phosphorylation of proteins regulating both plant immune responses and fungal pathogenesis. Hence, in this review, we present a summary of the current knowledge of protein kinase signaling pathways in plant-Colletotrichum interaction as well as the relation to a more general understanding of protein kinases that contribute to plant immunity and pathogen virulence. We highlight the potential of combining genomic resources and phosphoproteomics research to unravel the key molecular components of plant-Colletotrichum interactions. Understanding the molecular interactions between plants and Colletotrichum would not only facilitate molecular breeding of resistant cultivars but also help the development of novel strategies for controlling the anthracnose disease.
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Affiliation(s)
- Lingyan Jiang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, College of Tropical Crops, Hainan University, Haikou, China
| | - Shizi Zhang
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, College of Tropical Crops, Hainan University, Haikou, China
| | - Jianbin Su
- Division of Plant Sciences, Interdisciplinary Plant Group, Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, United States
| | - Scott C. Peck
- Division of Biochemistry, Interdisciplinary Plant Group, Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, United States
| | - Lijuan Luo
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, College of Tropical Crops, Hainan University, Haikou, China
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Usman HM, Tan Q, Fan F, Karim MM, Yin WX, Zhu FX, Luo CX. Sensitivity of Colletotrichum nymphaeae to Six Fungicides and Characterization of Fludioxonil-Resistant Isolates in China. PLANT DISEASE 2022; 106:165-173. [PMID: 34406787 DOI: 10.1094/pdis-05-21-0993-re] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Colletotrichum nymphaeae is the dominant species causing anthracnose disease of peach in China. In this study, 140 isolates of C. nymphaeae were assessed for their sensitivity to six fungicides. It was found that C. nymphaeae was highly resistant to carbendazim, procymidone, and boscalid but sensitive to pyraclostrobin and prochloraz. For fludioxonil, the fungus exhibited differential sensitivities (i.e., approximately 14% of isolates were resistant to fludioxonil and the resistance was stable). Fludioxonil-resistant isolates had a mean EC50 value of 2.2380 µg/ml, whereas the mean EC50 value was 0.0194 µg/ml in fludioxonil-sensitive isolates. The mean EC50 values of C. nymphaeae for pyraclostrobin and prochloraz were 0.0083 µg/ml and 0.002 µg/ml, respectively. No cross-resistance was observed between fungicides from different groups. Mycelial growth rate, control efficacy, and osmotic stress responses were significantly different (P < 0.05) between fludioxonil-sensitive (FluS) and -resistant (FluR) isolates, but no significant difference was observed (P > 0.05) in virulence and sporulation between FluS and FluR isolates. No mutation was detected in coding regions of the CnOs-1, Cal, Hk1, Hog1, TPI, and Mrr1 genes. Interestingly, with fludioxonil treatment, the expression of ABC transporter gene atrB was significantly overexpressed in some resistant isolates. However, overexpression of the atrB gene was not detected in one moderately and one highly resistant isolate, indicating that other unknown mechanisms may be involved. Current findings uncovered several effective chemicals and provided the foundation for designing management strategies to practically control peach anthracnose with the most effective demethylation inhibitor fungicides and quinone outside inhibitor fungicides.
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Affiliation(s)
- Hafiz Muhammad Usman
- Key Lab of Horticultural Plant Biology, Ministry of Education and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Qin Tan
- Key Lab of Horticultural Plant Biology, Ministry of Education and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Fei Fan
- Key Lab of Horticultural Plant Biology, Ministry of Education and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Mohammad Mazharul Karim
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
- Plant Pathology Division, Bangladesh Agricultural Research Institute, Gazipur 1701, Bangladesh
| | - Wei-Xiao Yin
- Hubei Key Lab of Plant Pathology and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Fu-Xing Zhu
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Chao-Xi Luo
- Key Lab of Horticultural Plant Biology, Ministry of Education and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
- Hubei Key Lab of Plant Pathology and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
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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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CgEnd3 Regulates Endocytosis, Appressorium Formation, and Virulence in the Poplar Anthracnose Fungus Colletotrichum gloeosporioides. Int J Mol Sci 2021; 22:ijms22084029. [PMID: 33919762 PMCID: PMC8103510 DOI: 10.3390/ijms22084029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/02/2021] [Accepted: 04/03/2021] [Indexed: 01/23/2023] Open
Abstract
The hemibiotrophic ascomycete fungus Colletotrichum gloeosporioides is the causal agent of anthracnose on numerous plants, and it causes considerable economic losses worldwide. Endocytosis is an essential cellular process in eukaryotic cells, but its roles in C. gloeosporioides remain unknown. In our study, we identified an endocytosis-related protein, CgEnd3, and knocked it out via polyethylene glycol (PEG)-mediated protoplast transformation. The lack of CgEnd3 resulted in severe defects in endocytosis. C. gloeosporioides infects its host through a specialized structure called appressorium, and ΔCgEnd3 showed deficient appressorium formation, melanization, turgor pressure accumulation, penetration ability of appressorium, cellophane membrane penetration, and pathogenicity. CgEnd3 also affected oxidant adaptation and the expression of core effectors during the early stage of infection. CgEnd3 contains one EF hand domain and four calcium ion-binding sites, and it is involved in calcium signaling. A lack of CgEnd3 changed the responses to cell-wall integrity agents and fungicide fludioxonil. However, CgEnd3 regulated appressorium formation and endocytosis in a calcium signaling-independent manner. Taken together, these results demonstrate that CgEnd3 plays pleiotropic roles in endocytosis, calcium signaling, cell-wall integrity, appressorium formation, penetration, and pathogenicity in C. gloeosporioides, and it suggests that CgEnd3 or endocytosis-related genes function as promising antifungal targets.
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Schnabel G, Tan Q, Schneider V, Ishii H. Inherent tolerance of Colletotrichum gloeosporioides to fludioxonil. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2021; 172:104767. [PMID: 33518054 DOI: 10.1016/j.pestbp.2020.104767] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 12/19/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
Colletotrichum spp. cause devastating diseases in agricultural crops, including fruit crops. They can differ in host plant and plant organ specificity and even in fungicide sensitivity. In strawberry, members of the C. gloeosporioides species complex (referred to as C. gloeosporioides) primarily cause crown rot and those of the C. acutatum species complex (referred to as C. acutatum) primarily cause fruit rot. Fludioxonil is registered for use (in combination with cyprodinil; Switch 62.5WG in the US) in strawberry against anthracnose disease caused by Colletotrichum spp. In this study we examined the sensitivity of C. gloeosporioides (C. fructicola and C. siamense) and C. acutatum (C. nymphaeae and C. fioriniae) isolates from different hosts and different geographical locations in the US to fludioxonil and examined possible mechanisms of inherent fungicide tolerance. The dose response to fludioxonil of C. gloeosporioides isolates (including 4 isolates of C. theobromicola) revealed about 70% inhibition of mycelial growth at 1 mg/L that was maintained at 10 mg/L and 100 mg/L and lead to minimum inhibitory concentration (MIC) values >100 mg/L. In contrast, mycelial growth of C. acutatum isolates was completely inhibited at 1 mg/L. C. gloeosporioides isolates were also significantly less sensitive to iprodione. An investigation into possible mechanisms of C. gloeosporioides isolates tolerance to fludioxonil and iprodione revealed no evidence of OS-1 gene involvement. Isolates of both species complexes were equally sensitive to salt stress based on mycelial growth inhibition on potato dextrose agar amended with 2%, 4%, and 6% NaCl. In addition, orthologous amino acid alterations in OS-1 previously linked to fludioxonil resistance in Botrytis cinerea were not found in C. gloeosporioides or C. acutatum isolates. This study also showed limited in vitro inhibitory activity of cyprodinil against isolates of both species complexes (MIC values >100 mg/L) and unveils a potential weakness of the fludioxonil+cyprodinil premixture marketed as Switch 62.5WG against C. gloeosporioides species complexes.
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Affiliation(s)
- Guido Schnabel
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634, United States of America.
| | - Qin Tan
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634, United States of America
| | - Verena Schneider
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634, United States of America
| | - Hideo Ishii
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634, United States of America; University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan
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