Analysis Of Drought Resistance And Physiological Mechanism Of Transgenic Wheat With GmDREB3 Gene

China’s major wheat producing areas are mostly in dry areas,and there exist droughts in varying degrees each,which lead reductions of output.Therefore,cultivating drought-resistant wheat varieties is one of the effective ways to maintain high yield and stable yield of wheat.With the development of transgenic technology,the use of transgenic technology to create drought-resistant transgenic wheat can greatly speed up the improvement of wheat varieties,shorten the breeding cycle,and ensure the safety of wheat productionAt present,plant drought resistance genomics research mostly focuses on model plants,we lack reports on crops,especially wheat drought resistance transgenic research.On the other hand,most of the drought resistance tests of transgenic plants were carried out indoors,lacking evidence of field trials.We identified and cloned the GmDREB3 gene from the salt-tolerant soybean cultivar Tiefong 8 by gene functional analysis in lab.The functional analysis showed that the GmDREB3 gene could significantly increase the drought resistance of Arabidopsis thaliana,and then,through the minimal expression box method of the gene gun,the GmDREB3 gene was transfonned into the wheat cultivar Jimai 22,and we obtained a new batch of transgenic wheat.In this paper,the field drought resistance of transgenic offspring is analyzed by field experiment,with the combination of physiological mechanism of drought resistance of transgenic wheat based on the determination analysis of physiological indexes.The results are as follows(1)Molecular detection of transgenic progeny:PCR was used to detect 8 strains of GmDREB3 gene T5,which were 16SY 46,16SY 48,16SY 56,16SY 57,16SY 63,16SY 211,16SY 217 and 16SY 318.The results show that all the 8 strains could be detected target gene.The GmDREB3 gene was integrated into the wheat genome and could be stably inherited.The 16SY318 strain was one of the transgenic strains used for the application of the productive test project.The results of RT-PCR show that GmDREB3 gene could be expressed in 16SY318 strain.Southern Blot results show that there was one copy of the GmDREB3 gene in the 16SY318 strain.The ELISA results showed that the GmDREB3 protein was expressed in the roots,stems,leaves and grains of the 16SY318 strain,and the expression of the root protein was the highest(2)Yield of transgenic progeny:Among the 8 transgenic strains of GmDREB3,the yield of transgenic strains have increased by 1.31%to 15.73%under drought treatment,among which the 16SY318 strain had a 16.7%increase of production.While the yield of transgenic strains have increased by-1.21%to 8.41%under water treatment,among which the 16SY318 strain had a production increase by 5.68%.The drought resistance index of the transgenic strains were among 1.01 to 1.27,and the drought resistance was moderate and strong.The drought resistance index of the 16SY318 strain was 1.27,and the drought resistance was strong(3)Research results of agronomic traits:The average plant height of GmDREB3 gene was 2.65%higher than that of the receptor under drought condition,among which 16SY48,16SY63 and 16SY318 have reached significant difference.While the average plant height of GmDREB3 gene was 3.055%higher than that of the receptor under water condition,among which 16SY63 and 16SY318 strains have reached significant difference.About the spikes of per mu,the average plant height of GmDREB3 gene was 3.83%higher than that of the receptor under drought condition,among which 16SY56 and 16SY318 strains have reached extremely significant difference,and 16SY46 and 16SY217 strains have reached significant difference.The average plant height of GmDREB3 gene was 5.1%higher than that of the receptor under water condition,among which 16SY56 and 16SY211 strains have reached extremely significant difference,and 16SY46 and 16SY217 strains have reached significant difference.About the grain number per spike,the average plant height of GmDREB3 gene was 5.47%higher than that of the receptor under drought condition,among which 16SY48,16SY63,16SY217 and 16SY318 strains have reached significant difference.While under water treatment,the average plant height of GmDREB3 gene was 2.65%higher than that of the receptor,among which 16SY48 and 16SY56 strains have reached significant difference About 1000-grain weight,the average plant height of GmDREB3 gene was respectively 0.01%and 1.55%higher than that of the receptor under drought and water treatments.The results showed that the yield increase of GmDREB3 transgenic wheat was mainly from the increase of spikes per mu and grains per spike(4)Analysis results of field physiological indicators:The chlorophyll content of 16SY46 and 16SY318 strains was higher than that of the control receptor group at the filling stage under the drought treatment,reaching a significant difference.While the difference was not significant under the water treatment.The chlorophyll fluorescence kinetics index Fv/Fm of the 16SY48,16SY217 and 16SY 318 strains was significantly higher than that of the control receptor under drought treatmen,while the Fv/Fm index of the 16SY57 and 16SY63 strains were significantly higher than that of the recptor under water treatment.The canopy temperature depression of the 16SY46,16SY48,16SY56,16SY63,16SY217 and 16SY318 strains was higher than that of the control receptor,reaching a significant difference.While the 16SY56,16SY211,16SY217 and 16SY318 strains were significantly higher than that of the recptor under water treatment.(5)Protein stability analysis results under simulation in vivo:The GmDREB3 protein was extremely unstable under simulated gastric fluid conditions.The GmDREB3 protein was extremely unstable under simulated intestinal fluid conditions.The GmDREB3 protein was stable under 90 ℃ heat treatment and it remained activity after heat treatment.The results showed that the GmDREB3 protein was extremely unstable under simulated gastrointestinal conditions but showed stablility under heat treatment.In conclusion,the yield of the GmDREB3 transgenic wheat was higher than that of the receptor under drought condition,and the increase of yield was mainly from the increase of the spikes per mu and the grains per spike.Through this study,we not only obtained the new genetically modified wheat with significant drought resistance,but also discussed the physiological mechanism of increasing drought resistance of transgenic wheat.All these above have laid foundations of improving the drought resistance of wheat in China.