陆地棉GhCDPK1基因响应干旱胁迫的功能初探

Preliminary Exploration for Function of Cotton GhCDPK1 Gene under Drought Stress

钙依赖性蛋白激酶(CDPKs)是一类重要的钙信号感受蛋白和响应蛋白,在植物干旱、低温、盐碱等非生物胁迫应答中起着重要的调控作用。为探讨陆地棉GhCDPK1基因在干旱胁迫下所起的作用,该研究利用实时荧光定量PCR技术分析了PEG模拟干旱胁迫下该基因的表达量,发现GhCDPK1基因受干旱胁迫诱导。通过构建植物表达载体pCAMBIA2300-GhCDPK1,采用农杆菌介导的叶盘法转化模式植物烟草,发现干旱胁迫下转基因植株保水能力明显高于野生型植株,叶绿素、脯氨酸、可溶性蛋白含量及POD、SOD活性也高于野生型植株,而丙二醛含量低于野生型植株。研究结果表明,GhCDPK1基因作为正向调控因子响应干旱胁迫诱导,过表达GhCDPK1基因可以使植株积累更多的渗透调节物质、增强抗氧化系统酶的活性和维持细胞膜的稳定性来提高植物抵御外界干旱胁迫的能力。

CDPKs（calcium-dependent protein kinases）are important calcium signal receptors and response proteins,which play important roles in response to various abiotic stresses in plants,such as drought,low temperature and salinity.To study the effect of cotton GhCDPK1 gene to drought stress,this study used quantitative real-time PCR to analyze the gene expression under PEG stress.The results showed that GhCDPK1 gene was up-regulated by drought stress.Moreover,plant expression vector was constructed and GhCDPK1 gene was introduced into tobacco by Agrobacturium-mediated leaf disk transformation method to identify the gene function.The results showed that after drought stress,the water retention capacity of transgenic plants was significantly higher than that of wild type plants;the contents of chlorophyll,proline,soluble protein and the activities of POD and SOD in transgenic tobacco plants were higher than that of wild type,whereas the content of MDA was lower than that of wild type plants.These results indicate that GhCDPK1 gene,as a positive regulator,was induced by drought stress,and over-expression of GhCDPK1 gene can enhance the ability of plants to resist drought stress by accumulating more osmotic adjustment substances,enhancing the activity of the antioxidant system and maintaining the stability of thecell membrane.