Overexpression of BnMAPK1 enhances resistance to Sclerotinia sclerotiorum in Brassica napus

Abstract

Plant MAPKs (mitogen-activated protein kinases) play an important role in defense to biotic and abiotic stresses. In our previous studies, BnMAPK1 was cloned in Brassica napus and transgenic oilseed rape plants overexpressing BnMAPK1 were obtained. In this study, B. napus ZY821DH line was used as control and the corresponding transgenic plants overexpressing BnMAPK1 were used as experimental materials. The resistance to S. sclerotiorum and oxalic acid content were tested by using detached leaves inoculated with the pathogen. The dynamic changes of the relative expression of four pathogenesis-related genes, OXO, Cu/Zn-SOD, PR2, and PR3 were detected in the leaves inoculated with the pathogen. The results showed that the overexpression of BnMAPK1 significantly inhibited the invasion of the pathogen, controlled the accumulation of oxalic acid in the inoculated leaves, and maybe finally relieved the negative regulation of OXO expression caused by the pathogen and up-regulated the expression of the other three genes, Cu/Zn-SOD, PR2, and PR3. The results indicated that overexpression of BnMAPK1 can effectively improve the resistance to S. sclerotiorum in oilseed rape.