《植物生理学报》 2015, 51(12): 2119-2125

干旱胁迫下平邑甜茶叶片交替呼吸途径上调对光破坏的防御作用

徐秀玉^1,*, 孙山^2,*, 金立桥¹, 刘美君¹, 高辉远^1,**

¹山东农业大学生命科学学院/作物生物学国家重点实验室, 山东泰安271018; ²山东省果树研究所, 山东泰安271000

通信作者：徐秀玉；E-mail: gaohy@sdau.edu.cn；Tel: 0538-8245985

摘　要：

以平邑甜茶为实验材料, 研究了干旱胁迫下线粒体交替氧化酶呼吸途径(AOX途径)对平邑甜茶叶片的光破坏防御作用。结果表明: 干旱胁迫下线粒体AOX的蛋白表达量及AOX途径的相对活性均显著增加; 强光下用水杨基羟肟酸(SHAM)抑制正常供水和干旱胁迫处理的植株的AOX途径后, 正常供水的平邑甜茶叶片的PSII最大光化学效率(F_v/F_m)、快速叶绿素荧光响应曲线中的J点相对可变荧光(V_J)、PSII反应中心关闭的比例(1–q_P)和光合线性电子传递速率(ETR)几乎不受影响, 而干旱胁迫下的平邑甜茶叶片的ETR和F_v/F_m显著下降, 1–q_P和V_J显著上升, 这表明干旱胁迫下抑制AOX途径后, 平邑甜茶叶片发生更严重的光抑制。上述结果表明: 干旱胁迫下, AOX途径在平邑甜茶叶片的光破坏防御中起重要的作用。

关键词：平邑甜茶; 线粒体交替呼吸途径; 干旱胁迫; 光破坏防御; 水杨基羟肟酸(SHAM)

收稿：2015-11-03   修定：2015-11-20

资助：山东省科学自然基金(ZR2012CM039)和作物生物学国家重点实验室开放基金(2012KF05)。

Up-Regulation of the Mitochondrial Alternative Oxidase Pathway Enhances Photoprotection in Malus hupehensis Leaves under Drought Stress

XU Xiu-Yu^1,*, SUN Shan^2,*, JIN Li-Qiao¹, LIU Mei-Jun¹, GAO Hui-Yuan^1,**

¹State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, Shandong 271018, China; ²Shandong Institute of Pomology, Tai’an, Shandong 271000, China

Corresponding author: XU Xiu-Yu; E-mail: gaohy@sdau.edu.cn; Tel: 0538-8245985

Abstract:

The role of mitochondrial alternative oxidase (AOX) pathway in photoprotection in Malus hupehensis leaves under drought stress was studied. The results indicated that drought increased the amount of leaf AOX protein and also enhanced the activity of AOX pathway. Under high light intensity, and after treated with salicylhydroxamic acid (SHAM) to inhibit the AOX pathway, the maximal photochemical efficiency of PSII (F_v/F_m), the J steps at the relative variable fluorescence kinetics (V_J), the PSII excitation pressure (1–q_P), and electron transport rate (ETR) was not affected in water-replete plants, while the ETR and F_v/F_m significantly decreased, while the 1–q_P and V_J significantly increased in drought-stressed plants, indicating that under droughtstress condition, the inhibition of AOX pathway caused more severe photoinhibition. The results demonstrate that the AOX pathway plays an important role in the photoprotection in M. hupehensis leaves under drought stress.

Key words: Malus hupehensis; mitochondrial alternative oxidase pathway; drought stress; photoprotection; salicylhydroxamic acid