以4℃处理的水稻品种辽盐241植株叶片总RNA为模板, 用基因特异引物通过RT-PCR扩增出1 700 bp的OsCDPK7基因。该基因序列比已报道的基因序列(GenBank登录号：AB042550)缺失了26个氨基酸, 而丝氨酸/苏氨酸蛋白激酶活性中心和钙结合结构域完整, 具备钙依赖的蛋白激酶活性。构建了由组成型启动子E12调控的OsCDPK7基因植物表达载体, 利用农杆菌介导法转化水稻, 经Km筛选及Southern杂交验证, 获得10株转基因植株。耐盐性分析表明：OsCDPK7基因的组成型表达提高了T₂代转基因植株的耐盐性, 部分转基因水稻在0.2 mol/L NaCl培养基中能够萌发; 幼苗期水稻经0.4 mol/L NaCl浇灌10 d, 去除胁迫后能恢复正常生长; 而对照在以上情况下均不能萌发和恢复。结果表明, 利用植物信号转导过程中的调控因子能够提高转基因作物的耐盐性。然而, 在不同耐性的转基因植株中, OsCDPK7基因的表达有一定的差异。

A 1 700 bp DNA fragment, OsCDPK7 gene, was cloned with RT-PCR from liaoyan241 leaf treated under a low temperature of 4℃. Compared to the OsCDPK7 gene reported before (GenBank accession No. AB042550), this fragment, lack of 26 amino acids, possesses the activity of Ca²⁺-dependent protein kinase because of a complete integration of the Ca²⁺ binding structure domain and Ser/Thr protein kinase activity center. Plant expression vector was constructed,, OsCDPK7 gene was regulated by E12 promoter. OsCDPK7 gene was transferred into rice via Agrobacterium-mediated method. After Km screening and Southern blot, 10 transgenic plants were obtained. The analysis on the salt tolerance showed that the expression of OsCDPK7 gene composition enhanced the salt tolerance of T₂ transgenic plants, part of T₂ transgenic seeds could germinate in 0.2 mol/L NaCl medium, and T2 transgenic young plants could rejuvenate after treatment with 0.4 mol/L NaCl for 10 days, while the controlled plants could not germinate and died in salt stress. This research finding proved that the regulation factor of the plant signal transduction could enhance the salt tolerance of transgenic plants, while OsCDPK7 expression was different in the different tolerence transgenic plants.