SlVQ15 Regulates Tomato Resistance To Botrytis Cinerea

Tomato is a widely grown vegetable,plays an important role in daily life,and has a high economic value.Botrytis cinerea is a fungal disease,which can infect tomato.Chemical control measures are mainly used to control B.cinerea,but bring instability to the ecological environment and product safety.Therefore,exploring the defesne genes of B.cinerea provides a more scientific method.Both the phytohormone jasmonate(JA)and the VQ motif-containing proteins play crucial roles in plant resistance to Botrytis cinerea.However,their crosstalk in resistance to Botrytis cinerea is unclear,especially in tomato(Solanum lycopersicum).In this study,we found that tomato VQ15 interacted with JA-ZIM domain proteins,repressors of the JA signaling pathway,and Sl WRKY31 to regulate tomato resistance to B.cinerea.The results are as follows:1.The real-time quantitative PCR analysis showed that SlVQ15 was highly induced by B.cinerea.Silencing SlVQ15 using virus-induced gene silencing reduced resistance to B.cinerea.2.SlVQ15-overexpressing lines(SlVQ15OE-1 and SlVQ15OE-2)enhanced tomato resistance to B.cinerea,and with B.cinerea-infection,the expressions of defense-related genes Sl TD and Sl PR-STH2 were significantly up-regulated.CRISPR/Cas9 gene editing lines(slvq15-c-1 and slvq15-c-2)reduced tomato resistance to B.cinerea,and with B.cinerea-infection,the expressions of Sl TD and Sl PR-STH2 were obviously down-regulated.These results suggested that SlVQ15 positively regulates tomato resistance to B.cinerea.3.Yeast two-hybrid(Y2H),firefly luciferase(LUC)complementation imaging(LCI)assays and pull-down assays demonstrated that SlVQ15 formes homodimers,and that its C-terminus is necessary and sufficient for the homomeric interaction.4.Y2 H,LCI and Pull down assays demonstrated that SlVQ15 interacts with Sl JAZ2,Sl JAZ5,Sl JAZ6,Sl JAZ7 and Sl JAZ11.Y2 H assays showed ath the N-terminus of Sl JAZs is required for the interaction with SlVQ15.5.Y2 H,LCI and Pull down assays demonstrated that SlVQ15 physically interacts with Sl WRKY31,while Sl JAZ11 inhibited the interaction between SlVQ15 and Sl WRKY31.6.SlVQ15 promotes the transcriptional activation function of Sl WRKY31.Sl JAZ11 inhibits the SlVQ15-promoted transcriptional activation activity of Sl WRKY31.7.In addition,we obtained a slwrky31 mutant(slwrky3-c)using CRISPR/Cas9 gene editing technology.Phenotypic analysis showed that the slwrky31-c mutant showed a higher susceptibility to B.cinerea.We further silenced SlVQ15 in slwrky31-c background and discovered that silencing SlVQ15 in slwrky31-c mutant caused decreased resistance to B.cinerea compared with slwrky31-c mutant.In conclusion,SlVQ15 interacts with Sl JAZs and Sl WRKY31 to regulate JA-mediated tomato resistance to B.cinerea.This study revealed the molecular mechanism of SlVQ15 resistance to B.cinerea,which provided a theoretical basis for breeding tomato resistant varieties.