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.