Preliminary Analysis Of Transgenic Poplars With PEPC Key Gene In C4 Plant Photosynthesis

Poplar is one of important timber species with fast-growing in China, and a wide range of uses. Phosphoenol pyruvate carboxylase (PEPC) plays a key role in C4 plant high efficiency photosynthesis. It is of a great significance to carry out poplar (C3 plants) high-efficiency genetic engineering research by use of C4 plants PEPC gene.In this study, Transgenic Poplar with PEPC gene for materials with the control transgenic plants (non-transgenic poplar) in the seedling growth, C4 photosynthesis-related activity, photosynthesis relevant parameters of a preliminary comparative analysis of high efficiency for selection of transgenic poplar provide the basis for new varieties. The main findings are as follows:(1)The enzymes in transgenic poplars related to C4 photosynthesis increased than the control, and PEPC activity increased significantly as high as 38.6 %.(2)Transgenic poplars have strong capacity for using high light intensity, and its light saturation point increased than the control by about 10% to 20%. The photosynthetic rates of transgenic poplars in light saturation point were higher than that of the control, and the light compensation points of transgenic poplars were lower than that of control.Also,the ability of transgenic poplars to use low light were stronger than the control.(3)CO₂ saturation point and CO₂ compensation point of transgenic poplars were lower than the control. The photorespiration of transgenic poplars was lower than that of control, which is favourable to photosynthetic formation and organics accumulation. In addition, the transgenic poplars had higher efficiency of carboxylation, the highest of which was higher than that of the control by 62.3 %, indicating that transgenic poplars have the ability to use more CO₂.(4)Photo-oxidation treatment, transgenic poplars original PSâ…¡photochemical efficiency, PSâ…¡photochemical efficiency and the actual decrease in photochemical quenching significantly reduced compared to the control; and transgenic plants increased the rate of non-photochemical quenching increased significantly than control.The show that the transgenic poplar with better heat dissipation capability and light oxidation.