It is well known that no chlorophyll synthesis and photosystem biogenesis have been detected in dark-grown angiosperm seedlings. However, in this report, we showed that both PSⅡ and PSⅠ could be formed in dark-grown lotus ( Nelumbo nucifera Gaertn.) seedlings. Lots of evidence were given: First, during the dark-grown period, the single fluorescence emission peak at 679 nm in lotus embryo red-shifted and transformed into the normal PSⅡ fluorescence emission; Simultaneously, PSⅠ fluorescence emission at 730 nm appeared and increased obviously; Second, with partial denaturing SDS-PAGE method, PSⅠ chlorophyll-protein complex could be clearly separated from 10 days dark-grown lotus seedlings; Third, the existence of Lhca1 was also proved by Western blots. Moreover, measurements of electron transfer rate demonstrated that both PSⅡand PSⅠ core in dark-grown lotus seedlings were photochemically active.
莲胚芽暗萌发过程中的光合系统发育研究
季宏伟 唐崇钦 李良璧 匡廷云*
（中国科学院植物研究所光合作用基础研究开放实验室，北京100093）
摘要：被子植物在黑暗中萌发生长不能合成叶绿素和建成光合系统,但是将莲(Nelumbo nucifera Gaertn.)胚芽置于黑暗中萌发生长时,却可以清楚地观察到它的光合系统进行发育: 首先,在原位低温荧光光谱上,LHCⅡ的荧光发射逐步红移变成典型的PSⅡ荧光发射,同时随着萌发时间的延长,PSⅠ的荧光发射也从无到有,逐渐增强;其次,对暗萌发10 d莲苗的叶绿体进行部分变性凝胶电泳分析也得到了PSⅠ的叶绿素蛋白复合物条带,通过Western blot s的蛋白免疫检测,在暗萌发莲苗中也证实了LHCⅠ组分中有Lhca1的存在;最后,对暗萌发莲苗叶绿体的PSⅡ和PSⅠ电子传递活性测量结果表明,在暗中发育形成的PSⅡ和PSⅠ核心都是有光化学活性的.文章讨论了莲胚芽暗萌发过程中进行光合系统发育的原因.
关键词： 莲；光合系统发育；暗萌发；Western blots
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