抽薹期叶绿素缺乏油菜突变体类囊体膜的研究

Study on the Thylakoid Membranes from A Chlorophyll-Deficient Oilseed Rape Mutant at the Bolting Stage

以抽薹期野生型油菜和黄化突变体叶片为材料,分析了叶片和类囊体膜的光合色素组成、色素与蛋白相对含量;比较了类囊体膜光谱特性(室温吸收光谱、荧光光谱和圆二色谱);用温和电泳、SDS-PAGE分析了类囊体色素蛋白和多肽组成。结果显示:与野生型相比,突变体叶片的蛋白质含量不变,而Chl a 和Chl b的含量均减少;突变体类囊体膜的Chl a/Chl b 比值较高,Chl/蛋白质比值较低,LHCII色素蛋白复合物的单体和三聚体含量明显减少。突变体的天线系统相对较小、捕光效率较低。

A comparative study on leaf and thylakoid membranes was made between a new oilse ed rape (Brassica napus) mutant Cr3529 and its wild type 3529 at the bolting stage. As compared with the wild type, Cr3529 possessed a lower content of chlo rophyll. The chlorophyll a/b ratio in the mutant was about 2-fold higher of that in the wild type. SDS-PAGE analysis showed that the content of the apoproteins of LHC II greatly declined in the mutant thylakoid membranes. The results from m ild electrophoresis and two-dimensional electrophoresis showed that the trimer L HCII (LHCII*) of mutant thylakoid membranes decreased. The room temperature abso rpation spectra, fluorescence spectra and cicular dichroism spectra indicated th at the mutant has lower efficiency of light-harvesting capacity and the size of antenna system in the mutant Cr3529 is smaller than that in wild type 3529.