Effect Of GABA On Wheat Under NaCl-stress And Cloning Of GABA Translocator Gene

γ-aminobutyric acid (GABA) is a free state exists in prokaryotes and eukaryotes extensive four-carbon non-protein amino acid, The GABA's content in the face of adversity stress could increased and play a protection role for plants.The wheat cultivar, Triticum aestivum'LiaoDa 01', under NaCl treatment at five levels, 0 mmol/L, 100 mmol/ L, 200mmol/L , 300mmol/L, 400mmol/L in the wheat seed germination process , were selected for GABA treatment trials salt stress concentration. in certain NaCl concentration conditions of NaCl stress, With the wheat two leaves exogenous 4 kinds of GABA concentration 0 mmol/L, 0.2mmol/L, 0.5mmol/L, 1mmol/L for processing. By measuring this nacl-stress physiological and biochemical indexes, such as the wheat germination percetage, seedling growth condition, enzymes activity, proline content, Fv/ Fm, chlorophyll content and membrane permeability, try to reveal the effects of exogenous GABA Concentration on Salt Tolerance of whea. then were cloned the wheat GABA transporter gene, and from the molecular level reveal to the effects of GABA salt tolerance.The main results and conclusions are as follows:1. As the salt concentration of wheat germination rate, germination index and vigor index index were decreased, in order to salt stress on wheat does not cause serious injury, choose 200mmol/L of salt concentration for the optimum conditions, in certain NaCl concentration conditions of NaCl stress exogenous GABA treated with wheat seeds and compared to the control facilities of wheat seed germination percetage of GABA is higher, and in the GABA concentration of 0.5mmol/L germinationpercetage, fresh weight, dry weight and relative water content forces the most significant effect. Root length increased with the increase of GABA concentration, GABA concentrations increased with the embryo more sensitive to GABA on wheat shows the ground and the underground parts of the sensitivity of different.2 .Under the NaCl stress, wheat, superoxide dismutase (SOD) activity in first and then decreased, under GABA concentrations in 0.5 mmol/L the catalase (CAT), peroxidase (POD) activity was first increased and then decreased , the concentration over 0.5mmol/L started to decrease its activity. Chlorophyll fluorescence maximum photosynthetic efficiency (Fv/Fm) values and significantly increased compared to the control, chlorophyll a, chlorophyll b, carotenoid content relative increase too, proline content decreased and then increased it began to decrease ,in the GABA concentration 0.5mmol/L when the highest content, afte put the exogenous GABA the accum- ulation of MDA and conductivity were significantly reduced, indicating GABA effectively alleviate wheat seedlings cell membrane lipid peroxidation under NaCl stress.3 .The effects caused by GABA to wheat growth and physiological and biochemical showed that GABA could increase the salt tolerance of wheat. And wheat GABA translocator gene was cloned to get the middle fragment together with 3' fragment, which laid the foundation of molecular biology for function research of GABA.