Photosystem Development in Dark-grown Lotus (Nelumbo nucifera) Seedlings

莲胚芽暗萌发过程中的光合系统发育研究(英文)

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 PS II and PS I could be formed in dark-grown lotus (Nelumbo nucifera Gaertn.) seedlings. Lots of evidence were given: First I during the dark-grown period, the single fluorescence emission peak at 679 nm in lotus embryo red-shifted and transformed into the normal PS II fluorescence emission; Simultaneously, PS I fluorescence emission at 730 nm appeared and increased obviously; Second, with partial denaturing SDS-PAGE method, PS I 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 PS II and PS I core in dark-grown lotus seedlings were photochemically active.

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 (NelumbonuciferaGaertn .)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 10d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Westernblots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。