外源施加AsA和MeJA对乙烯利诱导水稻叶片衰老的影响

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

摘要:

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。

Abstract:

The effects of exogenous ascorbic acid (AsA) and methy jasmonate (MeJA) on rice (Oryza sativa) leaf senescence induced by ethephon was investigated using wild type of cultivar line Zhonghua 11(ZH-11) and the mutant line GI-2 with down-regulated GLDH gene,which GLDH was a key enzyme in AsA biosynthesis path.The results showed that exogenous AsA increased ascorbic acid content in GI-2.Likewise,the contents of Rubisco protein and chlorophyll contents increased significantly after treated by AsA,and the descending rate of photosynthetic parameters decreased,while AsA treatment had no significant effects on ZH-11.In both cultivars,MeJA significantly decreased the contents of ascorbic acid,Rubisco protein and chlorophyll after treatment,while increased the descending rate of photosynthetic parameters,and had a stronger effect on ZH-11 than GI-2.Therefore,it was demonstrated that exogenous AsA plays an effective role in alleviating the early-senescence of rice leaf induced by ethephon,while MeJA has the opposite effects.