茉莉酸甲酯和油菜素内酯减轻苹果叶片光抑制的生理机制研究
Alleviation of Photoinhibition by Methyl Jasmonate and Brassinolide under Strong Light in Apple Leaves

以3 a生苹果为试材，研究茉莉酸甲酯（MeJA）和油菜素内酯（BR）对苹果叶片光合生理的影响，初步探究其减轻光抑制的机制。结果表明，MeJA和BR处理后Pn升高，叶片光合效能增强，但与气孔运动关。在引入PSⅡ修复抑制剂林可霉素（LinC）后，MeJA和BR对光抑制的缓解受阻，说明2种生长调节剂对叶片光抑制的减轻是通过促进受损PSⅡ修复来实现的。另外，MeJA和BR处理后活性氧积累减少，抗氧化酶活性升高也证实了这一结论。综合分析认为，MeJA和BR处理可以促进强光下受损PSⅡ的修复，维持较高的光化学活性，减少过剩激发能，避免光抑制现象的加剧。
In this study, we investigated effects of Methyl Jasmonate (MeJA) and Brassinolide (BR) on photosynthetic physiology and preliminarily explore its mechanism in alleviating photoinhibition in apple leaves. The results demonstrated that Pn increased, photochemistry efficiency and photosynthetic electron transport capacity were improved after treated by MeJA and BR, but it had nothing to do with stomatal movement. However, such increase was inhibited by the application of PSⅡ inhibitor LinC,The remission of MeJA and BR photoinhibition was blocked. This results showed that MeJA and BR alleviated photoinhibiton through facilitating the repair of PSⅡ. Subsequent reactive oxygen species (ROS) antioxidant enzymes trials confirmed the study. With MeJA and BR application, antioxidant enzymes activities improved and ROS accumulated less. As a consequence, the depression of PSⅡ repair could be reduced and apple leaves would maintain better photochemistry efficiency compared with control and protect photosynthetic apparatus from the damage of excess excitation and avoid the acceleration of photoinhibition.