Identification And Functional Analysis Of The Target Of Effector Protein Pst14872 In Puccinia Striiformis F.sp.tritici

As an important food crop in China,wheat is planted in a wide range,and its production safety is directly related to the national economy and people's livelihood.Wheat stripe rust is one of the common diseases in wheat.It is caused by Puccinia striiformis f.sp.tritici,which seriously damages wheat production.At present,the main way to control stripe rust is to cultivate resistant varieties and use chemical agents.However,due to its frequent virulence variation,the resistance of existing resistant varieties is easy to weaken or even lose,and the difficulty of control stripe rust is increased.Current studies have shown that some pathogenic factors,effector proteins,are secreted by the haustorium during the infection of Puccinia striiformis.Therefore,in order to deepen people's understanding of the pathogenesis of stripe rust and guide people's to control stripe rust,the research on these pathogenic factors has certain theoretical significance.In the previous study,we obtained an effector Pst14872 of stripe rust.On this basis,we screened and obtained several potential targets by yeast two hybrid screening technology,and confirmed a target protein TaClpS1 by yeast two hybrid,Pull-down and co-IP assay.In order to clarify the function of TaClpS1,we have performed further experiments.Sequence analysis of TaClpS1 showed that TaClpS1 encoded 162 amino acids and contained an evolutionarily conserved domain,CLPs.TaClpS1 was found to be specifically localized in the chloroplast when expressed transiently in wheat protoplasts.q RT-PCR assay showed that TaClpS1 was up-regulated in the early stage of Pst infection.Silencing TaClpS1 by virus-induced gene silencing(VIGS)resulted in an increase in resistance against Pst,combined with an increase in expression of TaPR1 and TaPR2 and accumulation of reactive oxygen species(ROS).In addition,histological observation showed that the number of haustorium,hyphal lengths and hyphal infection area were decreased at 24 hpi and 120 hpi.In conclusion,effector Pst14872 interacts with host protein TaClpS1,which negatively regulates wheat defense against wheat stripe rust.