寒地冬小麦TaEXPA7同源基因的遗传转化及其功能分析

膨胀素是一类具有非酶活性的细胞壁松弛蛋白,广泛参与植物生长的各个阶段,其表达受非生物胁迫如低温等调控。为了探究寒地冬小麦(Triticum aestivum)膨胀素基因 TaEXPA7-A/B/D的功能,本研究将 TaEXPA7-A/B/D三个基因分别转入拟南芥(Arabidopsis thaliana)中,利用抗性筛选和PCR鉴定,分别获得了过表达 TaEXPA7-A/B/D三个基因的转基因拟南芥植株,分别观察并测定了 TaEXPA7-A/B/D三个基因对转基因拟南芥生长和低温胁迫下生理指标的影响。结果表明,转基因拟南芥的根长、侧根数目、株高、开花后2周内的花序和角果数目均显著高于野生型;4℃低温处理后,转基因植株中抗氧化酶SOD、POD和CAT的活性及可溶性糖的含量相比于野生型均维持在较高的水平,且MDA的积累量较低。以上结果表明, TaEXPA7-A/B/D三个基因的过表达显著促进了转基因拟南芥的生长,并使植株在低温条件下维持更好的抗氧化和渗透调节能力。

Genetic Transformation and Functional Analysis of TaEXPA7 Homologous Gene in Winter Wheat in Cold Region

Expansin is a cell wall relaxing protein without enzyme activity. It is widely involved in plant growth and its expression is regulated by abiotic stress such as low temperature.To explore the function of the TaEXPA7-A/B/D in winter wheat(Triticum aestivum),we transformed three genes into Arabidopsis.The three genes expressed in the growth of over-expressed Arabidopsis and physiological indices under low temperature stress were observed and determined.In summary, our study suggested that the root length, number of lateral roots, plant height, number of inflorescences and pods within 2 weeks after flowering of transgenic Arabidopsis were significantly higher than those of wild type.The activities of SOD,POD,CAT and the content of soluble sugar in transgenic Arabidopsis were higher than those in wild type, but the accumulation of MDA was lower. The above results showed that the overexpression of TaEXPA7-A/B/D significantly promoted the growth of transgenic Arabidopsis and maintained better antioxidant and osmoregulation ability under low temperature.