Chang, LiLiChangYUH TZEANHsin, Kuan-TingKuan-TingHsinLin, Chia-YingChia-YingLinCHUN-NENG WANGLI CHANG2022-06-022022-06-022022-010028-646Xhttps://scholars.lib.ntu.edu.tw/handle/123456789/612479https://www.scopus.com/record/display.uri?eid=2-s2.0-85118116996&origin=recordpageViruses cause severe damage on crops, and identification of key gene(s) that can comprehensively activate antiviral immunity will provide insights for designing effective antiviral strategies. Salicylic acid (SA)-mediated antiviral immunity and RNA interference (RNAi) are two independently discovered antiviral pathways. Previously, we identified the orchid stress-associated protein (SAP), Pha13, which serves as a hub in SA-mediated antiviral immunity. As SAPs exist as a protein family, whether duplicated SAPs have redundant or distinctive functions in antiviral immunity remains elusive. We performed functional assays on orchid Pha21, a homolog of Pha13, using transient and transgenic approaches on orchid, Arabidopsis and Nicotiana benthamiana to overexpress and/or silence Pha21. The SA treatment induced the expression of both Pha13 and Pha21, whereas Pha21 was found to play a key role in the initiation of the RNAi pathway in Phalaenopsis orchids. We demonstrated that Pha21-mediated antiviral immunity and enhancement of the RNAi pathway is conserved between dicotyledons and monocotyledons. We provide new insight that orchid SAPs confer distinctive functions to coordinate both SA-signaling and RNAi for comprehensive activation of antiviral immunity, and this information will help us develop antiviral strategies on crops.A20/AN1 proteinantiviral immunityPhalaenopsis aphroditeRNA interferencesalicylic acid-mediated immunitystress-associated protein[SDGs]SDG2[SDGs]SDG13journal article10.1111/nph.17776346142152-s2.0-85118116996WOS:000711085500001