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Lin HC, de Ulzurrun GVD, Chen SA, Yang CT, Tay RJ, Iizuka T, Huang TY, Kuo CY, Gonçalves AP, Lin SY, Chang YC, Stajich JE, Schwarz EM, Hsueh YP. Key processes required for the different stages of fungal carnivory by a nematode-trapping fungus. PLoS Biol 2023; 21:e3002400. [PMID: 37988381 PMCID: PMC10662756 DOI: 10.1371/journal.pbio.3002400] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 10/24/2023] [Indexed: 11/23/2023] Open
Abstract
Nutritional deprivation triggers a switch from a saprotrophic to predatory lifestyle in soil-dwelling nematode-trapping fungi (NTF). In particular, the NTF Arthrobotrys oligospora secretes food and sex cues to lure nematodes to its mycelium and is triggered to develop specialized trapping devices. Captured nematodes are then invaded and digested by the fungus, thus serving as a food source. In this study, we examined the transcriptomic response of A. oligospora across the stages of sensing, trap development, and digestion upon exposure to the model nematode Caenorhabditis elegans. A. oligospora enacts a dynamic transcriptomic response, especially of protein secretion-related genes, in the presence of prey. Two-thirds of the predicted secretome of A. oligospora was up-regulated in the presence of C. elegans at all time points examined, and among these secreted proteins, 38.5% are predicted to be effector proteins. Furthermore, functional studies disrupting the t-SNARE protein Sso2 resulted in impaired ability to capture nematodes. Additionally, genes of the DUF3129 family, which are expanded in the genomes of several NTF, were highly up-regulated upon nematode exposure. We observed the accumulation of highly expressed DUF3129 proteins in trap cells, leading us to name members of this gene family as Trap Enriched Proteins (TEPs). Gene deletion of the most highly expressed TEP gene, TEP1, impairs the function of traps and prevents the fungus from capturing prey efficiently. In late stages of predation, we observed up-regulation of a variety of proteases, including metalloproteases. Following penetration of nematodes, these metalloproteases facilitate hyphal growth required for colonization of prey. These findings provide insights into the biology of the predatory lifestyle switch in a carnivorous fungus and provide frameworks for other fungal-nematode predator-prey systems.
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Affiliation(s)
- Hung-Che Lin
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | | | - Sheng-An Chen
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Ching-Ting Yang
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Rebecca J. Tay
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Tomoyo Iizuka
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Tsung-Yu Huang
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Chih-Yen Kuo
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - A. Pedro Gonçalves
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Siou-Ying Lin
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Yu-Chu Chang
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Jason E. Stajich
- Department of Microbiology and Plant Pathology, University of California, Riverside, California, United States of America
| | - Erich M. Schwarz
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Yen-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
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Inoue Y, Phuong Vy TT, Singkaravanit-Ogawa S, Zhang R, Yamada K, Ogawa T, Ishizuka J, Narusaka Y, Takano Y. Selective deployment of virulence effectors correlates with host specificity in a fungal plant pathogen. THE NEW PHYTOLOGIST 2023; 238:1578-1592. [PMID: 36939621 DOI: 10.1111/nph.18790] [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] [Received: 11/22/2022] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
The hemibiotrophic fungal plant pathogen Colletotrichum orbiculare is predicted to secrete hundreds of effector proteins when the pathogen infects cucurbit crops, such as cucumber and melon, and tobacco (Nicotiana benthamiana), a distantly related Solanaceae species. Here, we report the identification of sets of C. orbiculare effector genes that are differentially required for fungal virulence to two phylogenetically distant host species. Through targeted gene knockout screening of C. orbiculare 'core' effector candidates defined based on in planta gene expression, we identified: four host-specific virulence effectors (named effector proteins for cucurbit infection, or EPCs) that are required for full virulence of C. orbiculare to cucurbit hosts, but not to the Solanaceae host N. benthamiana; and five host-nonspecific virulence effectors, which collectively contribute to fungal virulence to both hosts. During host infection, only a small subset of genes, including the host-specific EPC effector genes, showed preferential expression on one of the hosts, while gene expression profiles of the majority of other genes, including the five host-nonspecific effector genes, were common to both hosts. This work suggests that C. orbiculare adopts a host-specific effector deployment strategy, in addition to general host-blind virulence mechanisms, for adaptation to cucurbit hosts.
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Affiliation(s)
- Yoshihiro Inoue
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | | | | | - Ru Zhang
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | - Kohji Yamada
- Graduate School of Technology, Industrial and Social Sciences, Tokushima University, Tokushima, 770-8513, Japan
| | - Taiki Ogawa
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | - Junya Ishizuka
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | - Yoshihiro Narusaka
- Research Institute for Biological Sciences, Okayama Prefectural Technology Center for Agriculture, Forestry and Fisheries, Okayama, 716-1241, Japan
| | - Yoshitaka Takano
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
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