Auxin-repressed Protein OsARP1 Interact With RGSV

Rice grassy stunt virus(RGSV)is belong to Tenuivirus,which is transmitted by the brown planthopper(Nilaparvata lugens)in a persistent manner.Rice grassy stunt disease was first found in Philippines in 1966,and occurred widely in rice-growing areas in South,Southeast,and East Asia.It was detected in Taiwan island and Fujian Province,respectively in 1970 and 1979.In southern Vietnam during 2006-2007,more than 485,000 hectare of paddy fields were severely affected by infection with RGSV,resulting in the loss of 828,000 tons of riee valued at US $ 120 million and directly affecting millions of rice farmers.However,the molecular mechanism of RGSV-infected rice is still unknown.Auxin,a important phytohormone,regulates a variety of growth and developmental processes in plants.ARP(Auxin-repressed protein)genes that are regulated by auxin.Most of them are from dormancy of biological tissues/organs,by outside or abiotic adversity stress separated tissues/organs,and is closely related to the growth and disease resistance in plants.Satoh based on the transcriptome responses of rive to RGSV infection,found OsARP1 gene expression is restrained.OsARP1-RNAi(RNA Interference)transgenic rice lines showed the phenotypic that inhibit plant growth,leaf blade narrow and enlarged lamina inclination,similar to the RGSV-infected rice.Using Gal4-based yeast two-hybrid(Y2H)system.The results demonstrated that OsARP1 interacts with p1,p3 and p5 encoded by RGSV.OsARP1 interacts with p3 and p5 were confirmed by subcellular co-localization assays.The p3 or p5 could enhance the pathogenicity of potato virus X(PYX)in Nicotiana benthamiana plants.OsARPI may participate in the RGSV pathogenic process.According to previous reports,the form of riee plant height and leaf angle are regulated by auxin.OsARP1-RNAi transgenic rice lines showed a similar phenotype that plant dwarf and increased lamina joint angle.In this paper,used Y2H system,we found that OsARP1 interacts with the most of proteins that derive from the families of ARF(Auxin response factor)and IAA(Auxin/Indole Acetic Acid).OsARP1 and auxin pathway may be has a correlation-closed.According to the results of Y2H,we could preliminary judgment that OsARP1 mediated rice dwarf and leaf angle inclination may be closely related with auxin pathways.