Identification Of Transgenic Wheat By The DREB Gene From Soybean/cotton And Determination Physiological And Biochemical Indexes

Drought and high salinity stresses are major responsible for the reduction of crop yield. In northern of china, aridity or half-aridity soil cover with major area planting wheat and water resource is restricted not to satisfied for irrigating crop and people living.Therefore, improving drought-tolerance of wheat cultivars is very important for crop production.256 transformated lines were obtained by biolistic bombarding with a DREB transcription factor GmDREB1 and GhDREB gene, from soybean and cotton. The results of PCR analysis in T0,T1 generation transgenic plants showed that the transformated genes could be inherited to next generation stably and transformated genes in some transgenic plants were separated in T1 generation according to the Mendelian disciplinarian. The results of identification of drought tolerance of some T1,T2 generation transgenic lines showed that the level of drought tolerance of the transgenic lines, GM245,GM246,GM247, were high than the wild type and GmDREB1 gene could improve transgenic wheat to drought tolerance. Moreover, PCR identification of T2,T3 generation transgenic plants using wheat cultivars Lumai 22 and Lumai 23 as donor showed that DREB genes could be inherited to next generation stably, and two lines, GM241 and GH20, more resistant to drought than that donor wheat were obtained.To study the change in physiology and metabolism of T2 generation transgenic lines, transgenic lines, GM241 and GH20, were planted in pots and content of soluble carbohydrate and proline in plant cell,transpiration rate and photosynthesis rate in the leaves of the transgenic wheat were investigated during booting stage to blooming stage. The results indicated that more low declining degree of photosynthesis rate were more low and rising speed of transpiration rate were more slow in transgenic lines than that in the wild type during drought treatment. After waterred, the transgenic plants recoveried faster than that in wild type wheat. More high level of content of soluble carbohydrate and proline were accumulated in transgenic lines than that in wild type wheat. These studies indicated that transgenic plants could stady the photosystem and normal metabolism by accumulated osmotic substance under drought stress condition. The analysis results of chlorophyII fluorescence parameters of leaves and content of soluble carbohydrate of T3 generation transgenic lines in land under drought stress condition showed that transgenic line 56-12-1 accumulated more high level of content of soluble carbohydrate after stress treatment.In conclusion, we obtained transgenic lines that were more tolerant to drought stress than that in wild type wheat, which would be advantaged to product high drought-tolerant wheat cultivars. Furthermore, studies of physiology and metabolism in transgenic wheat would be advantaged to uncover mechanism that GmDREB1 and GhDREB gene improve drought tolerant of transgenic plants.