Abstract:

To explore the differences of sesitivities to chill and strong light in indica and japonica rice (Oryza sativa), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under Chill condition and strong light. The contents of unsaturated fatty acids of thylakoid membrane lipids decreased and that of the saturated ones increased with the time of Chill- and strong lighttreatment, resulting in the reduction of the index of unsaturation of fatty acids (IUFA). The activities of violaxanthin deepoxidase (VDE), a key enzyme of xanthophyll cycle, also reduced. The content of violaxanthin (V) increased, and the contents of antheraxanthin (A) and zeaxanthin (Z) decreased, the ratio of (A+Z)/(A+Z+V) decreased correspondingly. Arrhenius analysis showed that VDE was sensitive to both chill and unsaturation level of thylakoid membrane lipids. Correlation analysis showed that there was distinctly positive relationships between IUFA of thylakoid membrane lipids and the activity of VDE, Fv/Fm, and D1 protein content. Lower IUFA values, less fluidity and stability of thylakoid membrane lipids, lower VDE activity and (A+Z)/(A+Z+V) ratio were found in indica rice cv. Shanyou 63 than in japonica rice cv. 9516 under chill and strong light.

低温强光下籼粳稻紫黄质脱环氧化酶活性和类囊体膜脂不饱和度的变化
季本华  曹云英  谢焕松  朱素琴 马 强 焦德茂

（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： 为了阐明籼稻(Oryza sativa L. spp. indica)、粳稻(O. sativa L. spp. japonica)对低温强光敏感性
的差异,着重研究了低温强光下水稻类囊体膜脂不饱和度与叶黄素循环的变化。随着低温强光处理时间的延长,类囊体膜脂不饱和脂肪酸含量降低,饱和脂肪酸含量增加,因而膜脂不饱和指数(IUFA)下降。同时,叶黄素循环的关键酶——紫黄质脱环氧化酶（VDE）活性降低,叶黄素循环组分中紫黄质（V）含量增加,而单环氧玉米黄质（A）和玉米黄质（Z）的含量减少,表现为(A+Z)/(A+Z+V)比值下降。Arrhenius分析证明,VDE对低温和膜脂不饱和度都敏感。相关分析表明,类囊体IUFA分别与VDE活性、(A+Z)/(A+Z+V)和D1蛋白量呈显著的正相关。与粳稻9516相比,籼稻汕优63类囊体膜的IUFA较低,低温下类囊体膜脂流动性和稳定性较差,VDE活性和(A+Z)/(A+Z+V)比值较低。
关键词： 类囊体膜脂；叶黄素循环；紫黄质脱环氧化酶；Arrhenius作图；水稻

通讯作者。E-mail: <photosyn@public1.ptt.js.cn>。