1.Identification And Characterization Of Interacting Proteins Of The Fungal Effector AvrPi9 In Rice 2.The Ribonuclease P Protein Subunit P30 Rpp30 Interacts With The Histone H4 Deacetylase HDT701 And Regulates Rice Immunity

The rice blast disease,caused by Magnaportha oryza,is the most devastating fungal disease of rice worldwide.For food security,it is important to study the interaction between rice and M.oryza,and uncover the pathogenesis and resistance mechanisms.There are two layers of plant immunity:PTI and ETI.The ETI is based on highly polymorphic resistance proteins that are activated upon the recognition of pathogen avirulence effectors,often associated with a hypersensitive response.To identify AvrPi9-interacting proteins(APINs)in rice,we used AvrPi9 as a bait protein in yeast two-hybrid screens in a rice cDNA library.GST Pull-down assays were used to verify the interaction between AvrPi9 and APINs.Genotype and phenotype identification of APIN1-RNAi transgenic plants indicated that APIN1 is associated with rice resistance to M.oryza.This part of research has provided a clue for the host target of AvrPi9 in rice cells.tRNAs are non-coding RNAs(-75 nt)transcribed by the RNA polymerase Ⅲand perform critical functions in protein synthesis.RNase P is a conserved and necessary endonuclease that processes the 5’ trailer of tRNA precursors.We focused on the interaction analysis between a subunit of RNase P(Rpp30)and histone H4 deacetylase(HDT701)in the second part of the research.Genotype and phenotype analyses of the Rpp30-OX and RNAi plants showed that Rpp30 positively regulates rice immunity.Three acetylation sites in Rpp30-N terminal conserved functional domain are also identified by LC-MS/MS,providing additional evidence for the interaction and modification between these two proteins.All together,this part of research uncovers the function of Rpp30 in the regulation of rice innate immunity,and provides new information on tRNA biological functions in plant immunity.