The Role Of Exogenous Ergothioneine In The Interaction Between Chinese Cabbage And Plasmodiophora Brassicae Wor.

Chinese cabbage(Brassica rapa L.ssp.pekinensis)is one of the most important sources of vegetables in Asia.Clubroot caused by P.brassicae has seriously threatened the growth and yield of Chinese cabbage.Ergothione(EGT)is a sulfur metabolite,which is widely found in animals and plants and can only be obtained by ingestion.Its unique antioxidant and cytoprotective effects have attracted wide attention.More and more studies have shown that secondary metabolites were directly related to the clubroot resistance of cruciferous plants.Previously,metabolome studies in our laboratory have shown that EGT was a significant differential metabolite in the interaction between Chinese cabbage and P.brassicae.At present,very less studies about the effect of EGT on plant disease resistance have been reported.It was found that EGT could significantly improve the resistance of Chinese cabbage to P.brassicae.In order to further explore the mechanism of EGT in improving the clubroot resistance of Chinese cabbage,the transcriptome sequencing technique was used to analyze the mechanism of EGT on the resistance of Chinese cabbage to P.brassicae.The main results are as follows:1.Under the treatment of 0.05 m M EGT,the root physiological indexes and root activity of Chinese cabbage were significantly higher than those of the control,and EGT promoted the root growth of Chinese cabbage.However,under the combined treatment of EGT and P.brassica,there was no significant difference in root physiological index and root activity between the ergothione treatment group and the control group,but the contents of malondialdehyde were significantly lower than those of the control.Exogenous ergothione reduced the degree of cell membrane damage in Chinese cabbage.2.Different concentrations of EGT were used to treat resting spores of P.brassicae.It was found that EGT could significantly reduce the germination rate of resting spores and directly kill P.brassicae.It may increase the resistance of Chinese cabbage to P.brassicae by directly inhibiting the germination of resting spores,but it does not show concentration dependence and will not increase with the increase of concentration.3.Through transcriptome sequencing analysis,it was found that the differential genes induced by EGT were significantly enriched in the phenylpropane biosynthesis(Phenylpropanoid biosynthesis)pathway,and the differential expressed genes encoded related enzymes involved in lignin synthesis and the expression was up-regulated.Through the q PTPCR verification of related genes,POD enzyme activity determination and lignin content determination,it was confirmed that EGT promoted the synthesis of Chinese cabbage lignin and improved the resistance of Chinese cabbage to P.brassicae.It was clear that EGT could promote root growth,inhibit the germination of resting spores of P.brassicae and induce the clubroot resistance of Chinese cabbage,and the biosynthesis pathway of phenylpropanes was activated in the process of inducing resistance.The accumulation of lignin plays an important role in inducing disease resistance.The results provide a new insight for the comprehensive control of clubroot of Chinese cabbage and further study on the action mechanism of EGT.