拟南芥AtCIPK23基因对烟草抗旱能力的影响

为了探索拟南芥AtCIPK23基因对烟草耐旱能力的影响，对3个转AtCIPK23基因阳性纯合株系KA13、KA14和KA44与野生型烟草K326（对照）进行了自然干旱处理，测定离体叶片的失水速率、叶绿素含量、相对电导率、脯氨酸和可溶性糖含量，并分析了转基因及野生型材料对活性氧的清除能力，对活性氧清除基因NtSOD、NtCAT和NtAPX及干旱胁迫相关基因NtDREB、NtLEA5和NtCDPK2的表达量进行检测。结果表明：（1）转基因烟草离体叶片的失水速率明显低于K326；自然干旱7 d后，野生型K326出现了明显的干旱胁迫症状；干旱7 d进行复水后，转基因株系的复水存活率明显高于K326。（2）转基因株系中的叶绿素、脯氨酸及可溶性糖含量比K326显著提高，电导率则明显降低。（3）野生型烟草K326中H₂O₂的积累量明显高于3个转基因株系，转基因株系中ROS清除机制的3个关键基因NtSOD、NtCAT和NtAPX被诱导上调表达。（4）抗旱相关基因NtDREB、NtLEA5和NtCDPK2仅在转基因烟草中受干旱诱导。研究认为，AtCIPK23基因可能具有提高植物抗旱能力的功能。

Physiological Response of Transgenic Tobacco Carrying AtCIPK23 Genes to Drought Stress

In order to study the roles of Arabidopsis AtCIPK23 gene played in response to drought stress, we treated three AtCIPK23 gene transgenic lines and wide type tobacco K326 by drought stress. The leaf water loss rate, proline, chlorophyll, soluble sugar contents and electrical conductivity were measured. Meanwhile, ROS elimination ability, and gene expression of ROS elimination and drought resistance related genes were analyzed. The results showed that: (1) the water loss speed of leaves detached from transgenic lines distinctly slower than that of K326. After 7 days of drought stress treatment in natural environment, K326 plants showed yellowish and withered. The re watering survival rate of transgenic lines was higher than that of K326 after 7 days drought stress. (2) The concents of proline, chlorophyll and soluble sugar in transgenic lines were obvious higher than that of K326. The electrical conductivity of transgenic lines leaves was significantly lower than that of K326. (3) Under drought stress, the accumulation of H₂O₂ in K326 was significantly higher than that of three transgenic lines, and three ROS elimination related genes NtSOD, NtCAT and NtAPX were up regulated only in the transgenic lines. (4) The drought resistance related genes NtAREB, NtLEA5 and NtCDPK2 were induced by drought stress in transgenic tobacco plants. These results suggest that the AtCIPK23 gene can improve the drought stress ability of transgenic tobacco.