【摘要】 研究了低温胁迫对水稻类囊体膜蛋白磷酸化和光能分配的影响。类囊体膜蛋白组分的SDS-PAGE和免疫印迹分析结果显示,低温弱光条件下光系统Ⅱ(PSⅡ)功能蛋白的稳态水平均有所降低。低温(77K)荧光分析表明,低温处理后类囊体膜光能吸收明显下降,而且FPSⅡ/FPSⅠ的比值均较对照组下降,表明低温弱光条件下有更多的激发能被分配到PSⅠ。低温处理同时还改变了类囊体膜蛋白磷酸化水平,捕光天线LHCⅡ蛋白中lhcb1的磷酸化水平明显降低,lhcb2的磷酸化水平增加,进一步证实lhcb2向PSⅠ移动,改变光能分配。PSⅡ反应中心D1、D2蛋白和核心天线CP43的磷酸化水平增高,有利于PSⅡ二聚体的稳定。更多还原

【Abstract】 Changes in the distribution of light energy in photosystem and the phosphorylation of the thylakoid membrane proteins in rice leaves(Oryza sativa L.)during chilling stress were studied.The SDS-PAGE of thylakoid membranes showed that the contents of most thylakoid polypeptides,especially the function proteins of photosystem Ⅱ,decreased during the chilling stress.Further immunoblot analysis indicated the LHCⅡ had a little drop and the reaction centre protein D2 was reduced greatly.In addition,the low temperature(77 K)fluorescence emission spectrum indicated that the light energy absorb drops obviously in the thylakoid membrane after chilling stress.The fact of reduction of FPSⅡ/FPSⅠ during the cold stress indicated the more excitation energies to assign to the light system Ⅰ.At the same time,the low-temperature treatment also changed the phosphorylation of the thylakiod membrane protein.Immunoblot analysis with phosphothreonine(Thr(P))antibody showed the phosphorylation of light harvesting complexes protein(lhcb1?lhcb4)was droped,obviously but the phosphorylation of lhcb2 was somewhat increased,it is also indicated the more excitation energies transfer to PSⅠ through lhcb2.In addition,the PSⅡ core proteins D1,D2 and CP43 phosphorylation level increased which play a key role in the stabilization of photosystem two dimmers.更多还原