摘要
Plants can produce reactive oxygen species(ROS)to counteract pathogen invasion,and pathogens have also evolved corresponding ROS scavenging strategies to promote infection and pathogenicity.Catalases(CATs)have been found to play pivotal roles in detoxifying H_(2)O_(2)formed by superoxide anion catalyzed by superoxide dismutases(SODs).However,few studies have addressed H_(2)O_(2)removing during rust fungi infection of wheat.In this study,we cloned a CAT gene PsCAT1 from Puccinia striiformis f.sp.tritici(Pst),which encodes a monofunctional heme-containing catalase.PsCAT1 exhibited a high degree of tolerance to pH and temperature,and forms high homopolymers.Heterologous complementation assays in Saccharomyces cerevisiae reveal that the signal peptide of PsCAT1 is functional.Overexpression of PsCAT1 enhanced S.cerevisiae resistance to H_(2)O_(2).Transient expression of PsCAT1 in Nicotiana benthamiana suppressed Bax-induced cell death.Knockdown of PsCAT1 using a host-induced gene silencing(HIGS)system led to the reduced virulence of Pst,which was correlated to H_(2)O_(2)accumulation in HIGS plants.These results indicate that PsCAT1 acts as an important pathogenicity factor that facilitates Pst infection by scavenging host-derived H_(2)O_(2).
基金
supported by the National Natural Science Foundation of China(31620103913 and U2003118)
Natural Science Basic Research Plan in Shaanxi Province of China(2020JZ-12),National“111 plan”(BP0719026)and Shaanxi Innovation Team Project(2018TD-004).
