摘要
以2年生温州蜜柑(Citrus unishiu Marc.)离体叶片为试材,利用叶绿素荧光探针、Western-blotting及抑制剂,研究了叶黄素循环、D1蛋白周转及电子传递在防御光破坏中的作用。结果表明,高温强光(40 ℃,2000 μmol·m-2·s-1)处理30min后,温州蜜柑叶片的初始荧光Fo显著升高,最大荧光Fm、非光化学猝灭系数NPQ、最大光能转化效率Fv/Fm及PSⅡ的量子产额ΦPSⅡ显著降低,同时,D1蛋白含量也大幅下降。用D1蛋白合成抑制剂林可霉素或叶黄素循环抑制剂二硫苏糖醇(DTT)饲喂叶片后,Fv/Fm、Fm、ETR(表观光合电子传递速率)、ΦPSⅡ和D1蛋白下降幅度增大,而且饲喂林可霉素的下降幅度大于饲喂DTT。使用电子传递抑制剂(DCMU)抑制叶圆片电子传递后,高温强光下Fo显著上升了78%,Fv/Fm和D1蛋白含量下降了33%和83%。这些结果表明,D1蛋白周转和叶黄素循环对温州蜜柑叶片光合机构光破坏有保护作用,而且D1蛋白周转的作用大于叶黄素循环,D1蛋白周转在一定程度上依赖于电子传递。
The role of D1 protein turnover,xanthophylls cycle and electron transport in protecting photosynthetic apparatus against photodamage in two-year old Satsuma mandarin（Citrus unishiu Marc.） detached leaves were investigated by using chlorophyll fluorescence,Western-blotting and inhibitors.The results showed that the initial fluorescence（Fo）increased significantly in leaves when exposed to high temperature and strong light（40 ℃,2 000 μmol · m-2 · s-1）for 30 min,on the other hand,maximum fluorescence（Fm）,non-photochemical quenching（NPQ）,maximal photochemical efficiency of PSⅡ（Fv/Fm）declined,and the D1 protein was degraded.Under high temperature and strong light,reduced levels of Fv/Fm,Fm,ETR（electron transport rate）,ΦPSⅡ （quantum yield of PSⅡ）and content of D1 protein were observed in dithiothreitol（DTT,xanthophylls cycle inhibitor）or lincomycin（D1 synthesis inhibitor）-fed leaves compared to non-fed ones.More severe decrease occurred in lincomycin-treated leaves than that in DTT-treated ones.After DCMU（an inhibitor of electron transport）was added onto leaves,under high temperature and strong light,Fo level increased by 78%,Fv/Fm value,while D1 protein content decreased by 33% and 83% respectively.These results suggest that the xanthophylls cycle and the D1 protein turnover might play important role in protecting photosynthetic apparatus of Satsuma mandarin leaves against photodamage,and the contribution of the D1 protein turnover to photo-protect is prior to xanthophylls cycle.From our results,it is apparent that the D1 protein turnover might depend on electron transport.
出处
《园艺学报》
CAS
CSCD
北大核心
2011年第2期205-214,共10页
Acta Horticulturae Sinica
基金
国家自然科学基金项目(30771497)
关键词
柑橘
温州蜜柑
高温强光
叶黄素循环
D1蛋白
叶绿素荧光
citrus
Satsuma mandarin
high temperature and strong light
xanthophylls cycle
D1 protein
chlorophyll fluorescence
