Induced resistance and mechanism of protein elicitor PevD1 against Verticillium dahliae in cotton

BU Bing-wu;QIU De-wen;ZENG Hong-mei;GUO Li-hua;YUAN Jing-jing;YANG Xiu-fen;Key Laboratory of Integrated Pest Management in Crop,Ministry of Agriculture,Institute of Plant Protection,Chinese Academy of Agricultural Science;

protein elicitor PevD1;;cotton Verticillium wilt;;Verticillium dahliae;;induced resistance;;defense response

PevDl,a secrete elicitor from Verticillium dahliae,activated hypersensitive response(HR) and systemic acquired resistance(SAR) in tobacco.In order to investigate the induced resistance and mechanisms of PevDl in cotton,the PevDl was expressed in E.coli and assayed the cotton resistance against V.dahliae and immune responses.The results showed that purified recombinant protein PevDl was not a phytotoxic factor in No.42 Xin-luzao cotton variety.Injection of PevDl in leaves improved cotton resistance at a concentration as low as8 μg/mL,the highest disease reduction was 35.04%at the 15~(th) day post V.dahliae inoculation.This protein was able to systemically induce hydrogen peroxide and nitric oxide generation,vessel reinforcement,lignin and terpenoids deposition.PevDl enhanced the expression of pathogenesis-related genes and lignin biosynthesis-related genes PAL,C4H1 and 4CL,and also increased enzyme activity of PAL,POD and PPO.The results demonstrated that the PevDl protein triggered the plant immune responses and improved disease resistance in cotton.The research not only lay a theoretical foundation for cotton Verticillium wilt disease control but also provided a scientific basis for elucidating plant-elicitor interactions.