【摘要】 Cd²⁺使叶绿体低温（77K）荧光发射光谱中 F686/F736及 F696/F736和激发光谱中F480/F436比值降低,说明 Cd²⁺不利于激发能向 PSⅡ传递。SDS-PAGE 分析表明,Cd（2+）处理后叶绿体类囊体膜中光系统Ⅱ捕光叶绿素蛋白质复合物 LHCⅡ的部分寡聚体解聚成单体,且 LHCⅡ的总量也减少了。分析表明 Cd²⁺使属于 LHCⅡ的多肽减少。已知LHCⅡ在光能吸收、传递以及激发能在两个光系统间的分配和调节方面起着重要作用,Cd²⁺引起部分 LHCⅡ解聚和总量减少,必然导致由 LHCⅡ捕获和向光系统Ⅱ中心传递的能量减少。更多还原

【Abstract】 The fluorescence emission and excitation spectra at 77 K showed that Cd²⁺ treatment re- duced the ratio of F686/F736,F696/F736 and F480/F436 in spinach chloroplasts.It is suggested that Cd²⁺ impeded the excitation energy transfer from light harvesting chlorophyll to PSⅡ trap. The chlorophyll protein complexes of spinach chloroplasts were resolved by SDS-PAGE.It showed that the total amount of LHCⅡ decreased after Cd²⁺ treatment.A decrease of 27 kD polypeptide in LHCII was also found by the treatment of Cd²⁺.Since LHCⅡ play an im- portant role in the absorption and transfer of light energy and the distribution of excitation energy between PSⅡ and PSⅠ,a decrease of LHCⅡ certainly may cause a decrease of excita- tion energy transfer from LHCⅡ to PSⅡ reaction center.更多还原