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Article|01 Oct 2020|OPEN
Involvement of CsWRKY70 in salicylic acid-induced citrus fruit resistance against Penicillium digitatum
Bing Deng1, Wenjun Wang1, Changqing Ruan1,2, Lili Deng1,2, Shixiang Yao1,2 & Kaifang Zeng1,2,
1College of Food Science, Southwest University, 400715 Chongqing, China
2Research Center of Food Storage & Logistics, Southwest University, 400715 Chongqing, China

Horticulture Research 7,
Article number: 20157 (2020)
doi: 10.1038/hortres.2020.157
Views: 75

Received: 23 Nov 2019
Revised: 23 Jun 2020
Accepted: 07 Jul 2020
Published online: 01 Oct 2020

Abstract

Penicillium digitatum causes serious losses in postharvest citrus fruit. Exogenous salicylic acid (SA) can induce fruit resistance against various pathogens, but the mechanism remains unclear. Herein, a transcriptome-based approach was used to investigate the underlying mechanism of SA-induced citrus fruit resistance against P. digitatum. We found that CsWRKY70 and genes related to methyl salicylate (MeSA) biosynthesis (salicylate carboxymethyltransferase, SAMT) were induced by exogenous SA. Moreover, significant MeSA accumulation was detected in the SA-treated citrus fruit. The potential involvement of CsWRKY70 in regulating CsSAMT expression in citrus fruit was studied. Subcellular localization, dual luciferase, and electrophoretic mobility shift assays and an analysis of transient expression in fruit peel revealed that the nucleus‐localized transcriptional activator CsWRKY70 can activate the CsSAMT promoter by recognizing the W-box element. Taken together, the findings from this study offer new insights into the transcriptional regulatory mechanism of exogenous SA-induced disease resistance in Citrus sinensis fruit.