Transformation Of Transcription Factor Gene DREB1 Responding To Drought Stress In Peanut

Peanut(Arachis hypogaea L.) is one of the most important oilseed and cash crop in China, which is mainly distributed in the arid and semi-arid areas. Now, the drought has affected peanut yield and quality of the primary limiting factor. DREB(dehydration responsive element binding protein) transcription factors primarily through abiotic stress signaling, regulating of expression of downstream genes related to a series of adversities to make plants resistant to abiotic stresses, such as low temperature drought and high salinity. This study selects 14 peanut varieties as materials,utilizes agrobacterium- mediated pathway for transforme DREB1 gene in peanut, analyzes the genetic transformation efficiency of different genotype varieties, and analyzes and detects the genetically modified materials from the level of gene and transcription, and drought resistance related to the physiological and biochemical properties change.The main findings are as follows:(1)Comparison of different peanut varieties of gene transfer efficiency14 peanut varieties embryo leaflet were selected receptors materials to carry out the genetic transformation of genes DREB1 in experiment.Frequency of callus inducement were significantly of 14 varieties in peanut. The callus inducement frequency of Fenghua 2 was 90.83%, which was significantly higher than other varieties, while the lowest was only 38.31%, which Yuanza9102 had. After 90-day-differentiation culture, 9 varieties differentiated adventitious bud differentiation. Fenghua2 had the highest adventitious bud differentiation rate which was 32.43%. Among 6 varieties the regeneration frequency and gene transformation frequency of Fenghua2 were 67.57% and 4.65% than theortheis respectively respectively, which was followed by Luhua8 and P10-2. Therefore, Fenghua2, Luhua8 and P10-2 were suitable as varieties of gene transformation receptor.(2)Gaining AhDREB1 gene transcription materialUsing Fenghua2 as receptor, 29565 explants were infested. The final results showed 26108 callus tissus, 4942 adventitious buds, 19300 regenerated plants were obtained respectively. After screening with 1 mol/L PPT, 1343 resistance seedlings were got. Using PCR, 122 PPT resistant plants which was the part of the screened seedlings were identificated.O nly 19 plants were proved to be transgenic, named as Y1~Y19.(3)Analysis expression of AhDREB1 in transgenic plantsThe expression of AhDREB1 in the Y1, Y2, Y3, Y4 transgenic plants were analyzed by using real time quantitative RT-PCR. There is difference on expression transcription levels of Ah DREB1 in four transgenic lines were significantly higher than in non-transgenic plants. The expression level of Ah DREB1 genes in Y1 lines, was 5.5 times higher than non-transgenic plants which was the highest among the four transgenic lines.(4)Changes of biochemical and physiology quota of 15% PEG resistance of Y1 linesWithout PEG treatment, the proline content and enzyme activities of SOD、POD、CAT in transgenic plants were significantly higher than non-transgenic plants, and the content of MDA was significantly lower than non-transgenic plants. After 6 h treatment with 15% PEG stress, the proline content and enzyme activities of SOD、POD、C AT in transgenic lines was significantly higher than that non-transgenic plants, and the content of MDA was significantly lower than non-transgenic plants.(5)Changes of phenotypic in Y1 strain after15% PEG stressDealing with 15% PEG for 3 days, the wilting degree of Y1 transgenic lines is less than the non-transgenic plants‘.