Functional identification of the OsMGD2 and OsMGD3 genes in rice and their influence on phosphorus deficiency in tobacco
[Objective]Monogalactose diglyceride synthase(MGD)is a key enzyme in the synthesis of mo-nogalactose diglyceride(MGDG)and plays an important role in plant response to low phosphorus toler-ance.We aim to understand the role of the OsMGD2 and OsMGD3 genes of rice in response to phosphorus(P)deficiency.[Methods]A pot experiment was conducted to analyze physiological responses and lipid composition changes of the wild-type(SR1)and transgenic tobacco under normal and low P condition.[Results]There was no difference in P content between the transgenic and wild-type tobacco under normal and P deficiency conditions.However,the biomass,chlorophyll content,and photosynthetic electronic transfer of the transgenic tobacco were higher than wild-type.The phospholipid(PL)content,digalactose diglyceride(DGDG)content,DGDG/MGDG ratio,and GL/PL ratio of the transgenic tobacco were higher than those of the wild-type tobacco under low phosphorus deficiency,and the lipid content and ratio of the tobacco expressing OsMGD3 were higher than the tobacco expressing OsMGD2.[Conclusion]Regulation of OsMGD2/3 gene expression in rice can improve lipid remodeling ability and maintain higher photosyn-thetic and growth capacity under phosphorus deficiency,increasing plant tolerance to low phosphorus stress.