Jasmonate increases terpene synthase expression, leading to strawberry resistance to Botrytis cinerea infection

Jasmonate induced FaTPS1 to produce terpene, and overexpression FaTPS1 led to fruit resistant against B. cinerea infection, FaMYC2 induced FaTPS1 by binding to its promoter that downstream of jasmonate. Jasmonic acid (JA) and its derivatives are associated with plant defence responses against pathogenic organisms. In the present study, a total of 10,631 differentially expressed genes, 239 differentially expressed proteins, and 229 differential metabolites were screened and found to be mainly involved in pathogen perception, hormone biosynthesis and signal transduction, photosynthesis, and secondary metabolism. In strawberry fruits, methyl jasmonate (MeJA) induced FaTPS1 expression and quickly increased the terpene content. Furthermore, FaTPS1 overexpression increased the emission of sesquiterpenes, especially germacrene D, and improved strawberry resistance against Botrytis cinerea infection, although the knockdown of FaTPS1 increased its susceptibility to the same pathogen. Using a yeast one-hybrid assay and transient expression analysis, we demonstrated that FaMYC2 can bind to the G-box element in the promoter region of FaTPS1, thus inducing FaTPS1 expression. MeJA also stimulated FaMYC2 expression and regulated downstream signalling cascades. Moreover, we presented a possible model of the new signalling pathway of MeJA-mediated strawberry resistance to B. cinerea.