Zinc finger transcription factorsBnaSTOP2sregulate sulfur metabolism and confer resistance toSclerotinia sclerotioruminBrassica napus

Abstract

ABSTRACTRapeseed (Brassica napusL.) has a high sulfur requirement for optimal growth, development, and pathogen resistance. In this study, we identified zinc finger transcription factors,BnaSTOP2s, that play key roles in sulfur metabolism andSclerotinia sclerotiorumresistance. First, our results suggested thatBnaSTOP2sare involved in sulfur as evidenced from extensive protein interaction screening. Knockout ofBnaSTOP2sreduced the response sensitivity in both sulfur-deficient and sulfur-excessive conditions by promoting the elongation of primary roots of seedlings. Furthermore, the content of essential sulfur-containing metabolites, including glucosinolate and glutathione, were substantially down-regulated in roots and leaves ofBnastop2mutants, which is consistent with the significantly lowered transcriptional levels of key players of GSL synthesis and transportation,BnaMYB28sandBnaGTR2s, respectively. Through comprehensive RNA-seq analysis, we revealed the substantial effect ofBnaSTOP2son sulfur metabolism from source to sink. Additionally, we observed a significant decrease while increase in leaf lesion sizes of theBnaSTOP2-OE andBnastop2mutants, respectively, when compared to the wild type duringSclerotinia sclerotioruminfection, suggesting the vital role ofBnaSTOP2in plant defense response. Overall, our findings highlight thatBnaSTOP2sseems to be global regulators of sulfur metabolism and confer resistance toSclerotinia sclerotioruminfection inB. napus.