The Impact On Nitrogen Metabolism In Oryza Sativa Of RGSV

Rice grassy stunt virus(RGSV) is a member of Tenuivirus, can cause rice grassy dwarf disease. In the 1970s in South Asia and southeast Asia,RGSV pandemic, caused serious economic losses. It is circulatively and propagatively transmitted by the brown planthopper(Nila parvata lugens). The geome of RGSV consists of 6 kinds of ssRNA, coded 12 proteins.To evaluate the effect on rice plants infected by RGSV over the transcript levels,we analyzed the expression of N-transporters.Transcriptlevelsfor N transporter were analyzed using real-time quantitative reverse transcription PCR,we found that high affinity and low affinity of nitrate transporter had up-regulated but not all, OsNRTl.1 OsNRT2.1 up-regulated 2.4 times and 2.8 times, respectively.The transporters of ammonium nitrogen OsAMT1.3,OsAMT3.1,OsAMT3.2 significantly up-regulated 3.1,10.9,14.8 times. The total nitrogen content of rice infected by RGSV rice were measured, the results show that total nitrogen content increased, which is consistent with the real-timePCR results.Analysis of the expression of miR167/ARF8 and miR393/AFB3 module,revealed an incoherent feed-forward mechanism that is induced by nitrate and repressed by N metabolites generated by nitrate reduction and assimilation.miR393/AFB3 and miR167/ARB8 are unique N-responsive module that controls root system architecture in respinse to external and internal navailability, which affects absorption of nitrate nitrogen and ammonium nitrogen in rice. Transformants for miR167 and miR393 gene in rice were produced by an Agrobacterium tumefaciens-mediated transformation method,and analysis the growth phenotype of TO generation plant. Our results indicated leaf etiolation, irregular patches and blade twist among TO plants.