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 ...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.展开更多
基金supported by the National Natural Science Foundation of China(Grant numbers 31772027 and 31972126).
文摘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.
