番茄根际酚酸累积对青枯菌入侵的影响OA北大核心CSTPCD

[Objective]This study aimed to investigate the effects of phenolic acid accumulation in the tomato rhizo-sphere on the invasion of Ralstonia solanacearum,providing theoretical support for elucidating the pathogenesis of to-mato bacterial wilt.[Method]The effects of 5 phenolic acid substances(phenylpropanoic acid,benzoic acid,caffeic acid,ferulic acid and syringic acid)on the growth of R.solanacearum were examined using 96-well plate culture.The changes in soil bacterial community diversity after phenolic acid accumulation were detected using high-throughput se-quencing methods.The population changes of R.solanacearum in soil were detected using selective culture media.Princi-pal component analysis(PCA),redundancy analysis(RDA)and correlation analysis were employed to analyze the ef-fects of soil bacterial community changes on the growth and reproduction of R.solanacearum under different phenolic acid treatments.[Result]Phenylpropanoic acid,benzoic acid,caffeic acid,ferulic acid and syringic acid promoted R.so-lanacearum growth,with caffeic acid showing the most obvious effect.The OD600 nm of R.solanacearum reached 0.17 in the caffeic acid treatment,which was significantly higher than those in other treatments(P<0.05,the same below).Com-pared with blank control,the continuous accumulation of each phenolic acid substance significantly reduced the diversity indexes of soil bacterial communities(Sobs,Shannon,ACE and Chao1 indexes).After benzoic acid,caffeic acid,feru-lic acid and syringic acid treatments,the dominant phyla shifted from Proteobacteria to Firmicutes.The relative abun-dance of Firmicutes in soil was the highest in the syringic acid treatment,reaching 90.4%.However,the phenylpropanoic acid treatment showed a significant different trend compared with other phenolic acid treatments,with Proteobacteria be-coming the dominant phylum(47.3%relative abundance).RDA revealed a positive correlation between relative abun-dance of Firmicutes and soil organic matter content,and a positive correlation between relative abundance of Proteobacte-ria and pH,NO3-N,NH4-N.After 28 d of R.solanacearum inoculation in soils treated with phenolic acids,the reproduc-tive quantity of R.solanacearum was significantly higher than that of blank control,with the highest population(8.16 lg CFU/g soil)observed in the syringic acid treatment.Correlation analysis showed that the population of R.solanacearum was significantly positively correlated with the relative abundance of Firmicutes,but it was significantly negatively corre-lated with the relative abundance of other communities.[Conclusion]The accumulation of phenolic acid substances in to-mato rhizosphere disrupts the soil bacterial community structure,weakening its resistance to R.solanacearum invasion and accelerating disease development.