FabHLH37调控草莓抗灰霉病的功能分析OA北大核心CSTPCD

[Objectives]This paper aimed to verify the function of strawberry bHLH(basic/helix-loop-helix)family transcription factor FabHLH37,and analyze the mechanism of its regulation of strawberry resistance to gray mold,so as to provide new gene resources for strawberry disease resistance breeding.[Methods]The total RNA of strawberry'Benihoppe'was extracted and reversely transcribed into cDNA.The FabHLH37 coding region sequence was cloned and bioinformatic analysis was performed using online software.Real-time quantitative PCR(qPCR)was used to detect the relative expression of this gene in different tissues of strawberry and in fruits inoculated with Botrytis cinerea.The subcellular localization of the gene was studied using the transient expression system of tobacco.The function of FabHLH37 against Botrytis cinerea was studied by transient expression system in strawberry fruits.[Results]The total length of FabHLH37 gene CDS was 789 bp,encoding 262 amino acids.The theoretical isoelectric point(pI)was 6.61,and the relative molecular weight was 2.9×105.Analysis of homologous evolution with different species of bHLH37 protein showed that FabHLH37 protein was closely related to the bHLH37 protein in Rosaceae crops such as rose and apple.The subcellular localization results showed that FabHLH37 was specifically expressed in the nucleus.The qPCR analysis showed that the expression of FabHLH37 was the highest in strawberry roots,followed by leaves,and the expression of FabHLH37 gene was significantly induced by Botrytis cinerea infection.The transient expression of FabHLH37 in strawberry fruits showed that compared with the control,strawberry fruits with overexpression of FabHLH37 were less susceptible to Botrytis cinerea inoculation,while strawberry fruits with silence of FabHLH37 were the opposite.Further qPCR detection showed that the expression levels of FaPR1/4/5-1,FaBG2-1,FaCHI3-1,FaSOD,FaPAL and other defense genes were positively correlated with the expression levels of FabHLH37 in the transient expression system of strawberry fruits.Overexpression of FabHLH37 could significantly increase the expression of these genes,while silencing FabHLH37 could significantly decrease the expression of these genes.[Conclusions]FabHLH37 transcription factor could positively regulate resistance to Botrytis cinerea by inducing the expression of defense genes in strawberry fruits.