外源施加AsA和MeJA对乙烯利诱导水稻叶片衰老的影响

以野生型水稻(Oryza sativa)株系中花11(ZH-11)及其抗坏血酸合成关键酶基因GLDH下调株系(GI-2)为材料,研究了外源抗坏血酸(AsA)与茉莉酸甲酯(MeJA)对乙烯利诱导下水稻叶片早衰现象的影响。结果表明,外源AsA提高了水稻GI-2中的抗坏血酸含量、Rubisco含量及叶绿素的含量,减缓了其光合特性参数的下降速率,但对水稻ZH-11没有显著影响。外源MeJA降低了两株系的抗坏血酸、Rubisco及叶绿素含量,加快了叶内光合特性参数的下降速率,且对ZH-11的影响大于GI-2。因此,外源AsA处理能有效缓解乙烯利诱导的水稻叶片早衰现象,使叶片的衰老进程得以延缓,而外源MeJA作用相反。

Effects of Exogenous Ascorbic Acid and Methy Jasmonate on Ethephon-induced Leaf Senescence in Rice

Effects of exogenous ascorbic acid (AsA) and methy jiasmonate (MeJA)on senescence of ethephon-induced rice leaves was investigated between wildtype of cultivar Zhong Hua11 (ZH-11) and the mutant of lines GI-2 with the down-regulated GLDH ( the key enzyme that catalyzes the final step of Asc biosynthesis in plants) gene. The results showed that exogenous AsA increased ascorbic acid contents in GI-2 after treatment. Likewise, the contents of Rubisco protein and chlorophyll contents in AsA-treated plants increased significantly after treatment, and the descending?rate of photosynthetic characteristics decreased, while AsA treatment had no significant effects on ZH-11. In both cultivars, MeJA decreased the contents of ascorbic acid, Rubisco protein and chlorophyll contents significantly after treatment, while increased the descending?rate of photosynthetic characteristics and had a stronger effect on ZH-11 compared to GI-2. These results demonstrated that exogenous AsA plays an effective role in alleviating the early-senescence of rice leaf induced by ethephon, while the treatment with MeJA has the?opposite?effect that it accelerates the senescence process of the rice leaf.