Photosynthesis And Physiological Impact Of Transgenic ERF Gene Aerobic Rice Under Saline-sodic Stress

Improve of the crop photosynthesis especially under stress is the main research topic in the recent years. It was supposed that enhance the crop photosynthesis is the key method to enhance the crop yield after the"Green Revolution"and using of heterosis, and increasing crop resistance is also the focus of attention of many scientific research works. Presently, the main study is introducing transcription factor which control transcription level into receptor plants. Transcription factor combine with cis-acting to regulation downstream gene expression which are the stress-related gene, ultimately increase crop yield and stress resistant.Ethylene responsive factors (ERFs) are the specific responsive factors of plant .TERF1 and LeERF2 are all belong to them. Adverse environmental conditions such as drought,high salt,extreme temperatures and pathogen attack greatly impair crop productivity. To survive these different biotic and abiotic stresses,plants have developed an elaborate signaling network that perceives these signals and modulates the expression of specific resistance genes. in these Pathways,Transcription factors play important roles in controlling the expression of specific tress-related genes. Ethylene responsive factors (ERFs) as downstream component of ethylene signaling pathway to modulate the expression of many stress-related genes through interaction with GCC box and DRE/CRT present in their promoters. In the present research, the T2 offspring of TERF1, LeERF2 and TERF1-LeERF2 transgenic rice was investigated to analyze the relation of photosynthetic capacity and stress tolerance under saline-sodic stress conditions. The main results were:(1) The TERF1, LeERF2 and TERF1-LeERF2 transgenic rice plants maintain higher germinations and growth rate than wild type under Na₂CO₃. Materially, transgenic double gene rice> transgenic single gene rice, but, there was no significant difference between transgenic TERF1and LeERF2 rice plants.(2) The LeERF2 transgenic rice plants maintain higher photosynthesis than wild type under NaCl stress. The present research show that the decrease of photosynthesis is because the low stomata conductance under 50mM NaCl, the decrease of photosynthesis is because the non stomata conductance under 100mM NaCl. Further more, the amplitude of variation increases with NaCl stress concentration.(3) Light curve and CO2 curve of rice tillering stage were determinations under 100mM NaCl. The results suggested that, before 100mM NaCl stress, Pnmax and AQY were no significant difference between the LeERF2 transgenic aerobic rice and wild type, after treated by 100mM NaCl stress, the transgenic aerobic rice maintained higher Pnmax and AQY than the wild type.(4)The TERF1-LeERF2 transgenic rice offspring plants shower higher photosynthesis capacity than the wild type under high temperature and high light conditions. But, there was no significant difference between transgenic single gene rice and the wild type. colony and correlation analysis suggested that Pn of the TERF1-LeERF2 transgenic rice offspring plants had a close correlation with ACE.