Mechanism Analysis Of The Rice Amino Acid Transporter OsMP1 Involved In Resistance To Magnaporthe Oryzae

Rice is one of the most important crops in the world,and solving the rice diseases is an effective way to increase yield,make high yield and stable yield of rice.The plants have evolved complex immune systems to deal with the infection of pathogens.In the early stage of the laboratory,the membrane protein gene OsMP1 was identified from gene chip and i TRAQ proteomics.The main results were as follows:It was found that most of the homologous proteins of OsMP1 were WAT1-related proteins,and WAT1 belonged to the Mt N21 family,so the evolutionary analysis of OsMP1and Mt N21 family in Arabidopsis showed that OsMP1 belonged to the group IV of the Mt N21 family,which were proved to have amino acid transport activity.Therefore,it is speculated that OsMP1 is an amino acid transporter.The expression of OsMP1 in resistant variety Heihezijing was significantly induced by Magnaporthe oryzae,but there was no significant induction of OsMP1 in susceptible variety Suyunuo.It showed that OsMP1 was involved in the regulation of resistance to Magnaporthe oryzae by inoculating the transgenic materials of OsMP1.We made microscopic observation on the transgenic materials of P_35S::OsMP1-GFP under the infection of Magnaporthe oryzae.We found that this gene was mainly enriched around the infected cells,which further indicated that the expressive location of this gene was related to the resistance to Magnaporthe oryzae.Then we determined the content of free amino acids in transgenic plant seeds.And it was showed that the seeds of overexpression lines contained almost less phenylalanine than Suyunuo and the seeds of osmp1 lines contained almost more serine、valine、isoleucine、phenylalanine、histidine than Heikezijing.We immersed rice roots into different amino acids solutions for 24 h,then sprayed Magnaporthe oryzae conidia onto Suyunuo.And it was found that glutamic acid and serine treatment could increase the resistance of Magnaporthe oryzae.Besides OsMP1 could respond to the induction of glutamic acid and serine.Therefore,it is speculated that OsMP1 may transport glutamate and serine.Then the expression in xenopus oocytes shows that OsMP1 mediates both amino acid import and export.And it is suggested that OsMP1 can mediate the growth of yeast cells on the medium with a variety of amino acids,and its substrate specificity in yeast cells is very extensive.It was showed that it was highly expressed in young panicles of resistant varieties by OsMP1 expression analysis of different organs,and the expression of OsMP1 affected the weight of seeds,indicating that the amino acid transporter OsMP1 may be related to the loading of amino acids in phloem of panicle.It was found that the expression of OsMP1 affected the expression of ATPase gene coupled with transmembrane transport and plant hormone signal transduction pathway by RNA-seq analysisin CRISPR/Cas9 knockout-transgenic materials and control Heikezijing.Combined with the analysis of related genes,it is speculated that the mechanism of OsMP1is that Magnaporthe oryzae affects the expression of OsMP1,the concentration of intracellular amino acids and H⁺,thus affecting the role of organelle amino acid transporters,and changing the content of amino acids in cytoplasmic matrix and organelles.Therefore it triggers immune systems in plants and causes changes in SA/JA and hormone networks in plants,which activates downstream genes to play a role.