叶绿素缺乏油菜突变体的LHCⅡ多肽组成、蛋白含量与cab基因转录研究

Study on the polypeptide composition and content of LHCⅡ and the cab gene transcription in chlorophyll-reduced mutant of oilseed rape seedlings

与野生型油菜相比 ,叶绿素缺乏油菜突变体 Cr35 2 9L HC 多肽组成并未发生改变 ,但其含量却都明显降低 .RNA印迹及点杂交结果都显示出 Cr35 2 9cab基因的转录增加 .这些结果表明 :该叶绿素缺乏突变体仅影响L HC 多肽的蛋白含量 ;并未影响其组成 ;突变体 L HC 蛋白量的减少并非 cab基因转录降低所致 .可见转录水平的调节仅对 L HC 在类囊体膜上的积累起有限作用 ;

Compared to the wild type oilseed rape,there were no changes of LHCⅡ polypeptide composition in the thylakoid membranes of mutant type Cr3529 .While the content of the 3 polypeptides was markedly declined.RNA gel blot and dot blot analysis indicated that the abundance of cab transcript in Cr3529 was higher than that in the wild type.These results suggest that,reduced chlorophyll level of the mutant type only has influence on the content of LHCⅡ polypeptides,while no effect on the polypeptide composition.The lower LHCⅡ content in the mutant type isnt due to the decreased cab transcription,and the transcriptional regulation only plays a limited role in the accumulation of physiological amounts LHCⅡ within thylakoid membranes.The integrity of chloroplast is not necessary for the maintaince of nuclear gene cab transcription and the synthesis of plastid signal.