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作 者 ：郭春爱;周玮;刘芳;许晓明

期 刊 ：作物学报 2007年 33卷 08期 页码：1390-1392

关键词：水稻；热稳定性；低叶绿素b突变体；叶绿素荧光参数；光系统Ⅱ；

Keywords:Rice, Thermostability, Low chlorophyll b mutant, Chlorophyll fluorescence parameters, PhotosystemⅡ,

摘 要 ：

通过测定不同温度处理后水稻低叶绿素b突变体及其野生型(镇恢249)叶绿素荧光参数和快速荧光诱导动力学曲线的变化，研究了低叶绿素b对突变体光系统Ⅱ热稳定性的影响。结果表明，突变体荧光参数F_o快速升高的温度拐点(43℃)比野生型(46℃)低3℃。升温到40℃以上，两者多相荧光曲线开始出现明显的K点，说明高温伤害了放氧复合体(OEC)，且突变体受伤害的程度大于野生型。同时，高温引发PSⅡ反应中心失活。总之，低叶绿素b突变体对高温更敏感，PSⅡ捕光色素蛋白复合体(LHCⅡ)中叶绿素b减少可能降低了PSⅡ结构与功能的热稳定性。

Abstract:

Low chlorophyll b rice mutant and the wild type rice (Zhenhui 249) were used to study the effects of low chlorophyll b on thermostability of photosystemⅡ in mutant by measuring their changes in chlorophyll fluorescence parameters and polyphasic chlorophyll fluorescence transients under different temperature treatments. The results showed that the temperature of Fo rising threshold was shifted 3℃ lower in the mutant (43℃) than in the wild type (46℃). At temperature up to over 40℃, O-J-I-P transient was transformed into O-K-J-I-P transient, a very clear K point appeared, this suggested that high temperature damaged the oxygen evolving complex (OEC), and the degree of damage was severer in mutant than in the wild type. In addition, high temperature led to inactivation of PSⅡ reaction centre. All results indicated that the mutant showed a tendency for higher thermosensitivity, and the decrease of chlorophyll b in LHCII could lead to less thermostability of PSⅡ structure and function.

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