Abstract:【Objective】 Monogalactose diglyceride synthase (MGD) is a key enzyme in the synthesis of monogalactose diglyceride (MGDG) and plays an important role in plant response to low phosphorus tolerance. To systematically understand the role and function of OsMGD2 and OsMGD3 genes in response to phosphorus(P) deficiency. 【Methods】 A pot experiment was conducted to analysis physiological responses and lipid composition changes of wild-type (SR1) and transgenic tobacco under normal and P deficiency condition.【Results】 The was no difference in P content between transgenic and wild-type tobacco under normal and P deficiency conditions. However, the biomass, chlorophyll content, and photosynthetic electronic transfer of transgenic tobacco were significantly higher than wild type. The phospholipid (PL) content, digalactose diglyceride (DGDG) content, DGDG/MGDG ratio and galactosyllipid (GL)/PL ratio of transgenic tobacco were significantly higher than those of wild type tobacco under low phosphorus deficiency, and the lipid content and ratio of OsMGD3 transgenic tobacco were higher than OsMGD2 transgenic tobacco.【Conclusion】 Regulation of OsMGD2/3 gene expression in rice can improve the membrane lipid remodeling ability of plants under phosphorus deficiency, maintain the higher photosynthetic and growth capacity of plants under phosphorus deficiency, and increase the plant tolerance to low phosphorus stress.