Guanosine-specific single-stranded ribonuclease effectors of a phytopathogenic fungus potentiate host immune responses.

Autor: Kumakura N; RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan., Singkaravanit-Ogawa S; Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan., Gan P; RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan., Tsushima A; RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan.; Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan., Ishihama N; RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan., Watanabe S; RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan., Seo M; RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan.; Tropical Biosphere Research Center, University of the Ryukyus, Nakagami, Okinawa, 903-0213, Japan., Iwasaki S; RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan.; Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8561, Japan., Narusaka M; Okayama Prefectural Technology Center for Agriculture, Forestry, and Fisheries, Research Institute for Biological Sciences, Kaga, Okayama, 716-1241, Japan., Narusaka Y; Okayama Prefectural Technology Center for Agriculture, Forestry, and Fisheries, Research Institute for Biological Sciences, Kaga, Okayama, 716-1241, Japan., Takano Y; Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan., Shirasu K; RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan.; Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan.
Jazyk: angličtina
Zdroj: The New phytologist [New Phytol] 2024 Apr; Vol. 242 (1), pp. 170-191. Date of Electronic Publication: 2024 Feb 13.
DOI: 10.1111/nph.19582
Abstrakt: Plants activate immunity upon recognition of pathogen-associated molecular patterns. Although phytopathogens have evolved a set of effector proteins to counteract plant immunity, some effectors are perceived by hosts and induce immune responses. Here, we show that two secreted ribonuclease effectors, SRN1 and SRN2, encoded in a phytopathogenic fungus, Colletotrichum orbiculare, induce cell death in a signal peptide- and catalytic residue-dependent manner, when transiently expressed in Nicotiana benthamiana. The pervasive presence of SRN genes across Colletotrichum species suggested the conserved roles. Using a transient gene expression system in cucumber (Cucumis sativus), an original host of C. orbiculare, we show that SRN1 and SRN2 potentiate host pattern-triggered immunity responses. Consistent with this, C. orbiculare SRN1 and SRN2 deletion mutants exhibited increased virulence on the host. In vitro analysis revealed that SRN1 specifically cleaves single-stranded RNAs at guanosine, leaving a 3'-end phosphate. Importantly, the potentiation of C. sativus responses by SRN1 and SRN2, present in the apoplast, depends on ribonuclease catalytic residues. We propose that the pathogen-derived apoplastic guanosine-specific single-stranded endoribonucleases lead to immunity potentiation in plants.
(© 2024 The Authors New Phytologist © 2024 New Phytologist Foundation.)
Databáze: MEDLINE
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