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AP2/ERF转录因子普遍存在于植物中,并广泛参与植物对生物和非生物胁迫的响应。为了提高棉花对病害及非生物逆境的抵抗能力,将分别从抗逆性优良的沙生植物铃铛刺(Halimodendron halodendron)和胡杨(Populus euphratica)中分离的Hh ERF2和Pe DREB2a转录因子基因构建以rd29A为启动子的表达载体,并通过花粉管通道法转化棉花。利用Real-time PCR分析胁迫处理的转基因阳性植株Hh ERF2和Pe DREB2a基因异位表达及下游PR(pathogenesis-related protein)基因表达情况,结果表明在病原菌、干旱和盐胁迫下转基因植株体内Hh ERF2基因能够超表达,而Pe DREB2a基因仅在干旱和盐胁迫诱导下超表达。接种大丽轮枝菌(Verticillium dahlia)后能够诱导转基因植株相关PR基因表达,同时与对照J12相比植株体内PAL、SOD和POD等酚类代谢相关酶的活性显著增加,且增强了转基因棉花对大丽轮枝菌的抵抗能力。干旱和高盐胁迫下生理生化特性分析表明,与对照相比,转基因棉花叶片中可溶性碳水化合物和相对含水量显著升高,而电导率和丙二醛(MDA)含量显著降低。因此,转基因棉花对大丽轮枝菌及干旱和高盐胁迫表现出了较强的耐受能力。
AP2 / ERF transcription factors are ubiquitous in plants and are widely involved in plant responses to both biotic and abiotic stresses. In order to improve the resistance of cotton to disease and abiotic stresses, Hh ERF2 and Pe DREB2a transcription factor genes isolated from Halimodendron halodendron and Populus euphratica, respectively, were used to construct rd29A For the promoter expression vector, and transformed cotton by pollen tube pathway. The expression of Hh ERF2 and Pe DREB2a genes and the expression of downstream pathogenesis-related proteins (PRs) in stress-treated transgenic plants were analyzed by Real-time PCR. The results showed that the expression of Hh ERF2 gene in transgenic plants under pathogen, drought and salt stress Overexpression, while Pe DREB2a gene overexpression only induced by drought and salt stress. Inoculation of Verticillium dahlia induced the expression of PR gene in transgenic plants, and compared with control J12, the activity of enzymes related to the metabolism of phenols such as PAL, SOD and POD increased significantly, Resistant to Verticillium dahliae. Physiological and biochemical characteristics under drought and salt stress showed that the soluble carbohydrate and relative water content of transgenic cotton leaves were significantly increased while the contents of electrical conductivity and malondialdehyde (MDA) were significantly decreased compared with the control. Therefore, transgenic cotton showed strong tolerance to Verticillium dahliae and drought and salt stress.