Physiological indices related to the efficiency （ Fv/Fm ） of light energy conversion in PSⅡ and the peroxidation of membrane lipid were measured in leaves of Oryza sativa L. sp. indica rice cv. “Shanyou 63” and sp. japonica rice cv. “9516” under different temperatures and light intensities for 4 days. No changes in Fv/Fm and membrane lipid peroxidation product (MDA) were observed, so neither photoinhibition nor photooxidation happened in both rice cultivars under moderate temperature and medium light intensity. However, Fv/Fm dropped obviously with no change in MDA contents, and photoinhibition appeared in indica rice cv. “Shanyou 63” under medium temperature and strong light intensity. Furthermore, both photoinhibition and photooxidation were observed in two rice cultivars under chilling temperature and strong light intensity. Experiments with inhibitors under chilling temperature and strong light intensity showed that indica rice had a decrease in D1 protein content and SOD activity, and the extent of inhibition of xanthophyll cycle and nonphotochemical quenching ( qN ) was larger, and a higher level of MDA was observed. The photoinhibition and photooxidation in indica rice were more distinct as compared with japonica rice. The authors suggested that PSⅡ light energy conversion efficiency ( Fv/Fm ) and membrane lipid peroxidation were the key indices for the detection of photooxidation.
不同温光条件下籼粳稻叶片的光抑制和光氧化表现
季本华1,2 焦德茂1*
（1. 江苏农业科学院农业生物遗传生理研究所，南京210014；2. 南通师范学院生命科学与技术系，南通226007）
摘要：不同温光条件(4 d)下,以粳稻(Oryza sativa L. sp. japonica)“9516”和籼稻(O. sativa L. sp. indica)“汕优63”为材料,测定了与PSⅡ光能转化效率 (Fv/Fm)和膜脂过氧化作用有关的生理指标,结果表明:适温、中等光强下两品种 Fv/Fm和膜脂过氧化作用的产物(MDA)无变化,未见光抑制和光氧化表现;适温、强光下籼稻“汕优63”的Fv/Fm明显下降,MDA未见变化, 有光抑制无光氧化表现;低温、强光下两品种有光抑制和光氧化表现。低温、强光下结合抑制剂实验证明,与粳稻相比 ,籼稻的D1蛋白量和SOD活性下降较多,叶黄素循环和非光化学猝灭(qN)受抑制程度较大,膜脂过氧化产物MDA含量较高,因而光抑制和光氧化现象较明显。实验提出:光能转化效率和膜脂过氧化表现是预测光氧化的关键指标。
关键词： D1 蛋白；psII光能转化效率(Fv/Fm)；叶黄素循环；非光化学猝灭（qN）；膜脂过氧化；水稻
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