摘要
Influence of high light stress on the photosynthesis of flag leaves of indica subspecies (cv. “Shanyou 63', sensitive to photoinhibition) and japonica subspecies (cv. “Wuyujing', resistant to photoinhibition) of rice ( Oryza sativa L.) was comparatively investigated. In both cultivars of rice, the excitation energy distribution between two photosystems was altered and the excitation energy transfer from light harvesting chlorophyll protein complexes to PSⅡ was inhibited by high light stress. These decreases were more pronounced in indica rice cultivar as compared to japonica one. The analysis of mild SDS_PAGE showed that in indica rice, high light stress almost disaggregated the trimer of light harvesting chlorophyll protein complexes of PSⅡ (LHC Ⅱ 1). The stress reduced the contents of internal antennae chlorophyll protein complexes of PSⅡ (CPa), light harvesting chlorophyll protein of PSⅠ (CPⅠa) and Chl a protein complex of PSⅠ reaction center (CPⅠ) as well as dimer of LHCⅡ (LHCⅡ 2) in indica rice. In japonica subspecies, however, high light stress depressed the contents of LHCⅡ 1, CPa and CPⅠa, but slightly impacted on CPⅠ content. Moreover, the increase in the contents of monomer of LHCⅡ by high light stress was found in both subspecies. In consistent with above results, analysis of polypeptide indicated that the amounts of 27 kD and 25 kD polypeptide of LHCⅡ in particular, as well as that of 21 kD polypeptide of CPⅠa were reduced by high light stress in both subspecies. It was found that, comparing with japonica rice, the stress pronouncedly diminished 43 kD and 47 kD proteins of CPa and 23 kD extrisic protein in indica rice.
以耐光抑制的水稻 (OryzasativaL .)粳亚种品种“武育粳”和对光抑制敏感的籼亚种品种“汕优 6 3”的剑叶为材料 ,比较研究了高光胁迫对水稻两个亚种光合系统的影响。结果表明 ,高光胁迫影响激发能在两个光系统之间的分配 ,抑制激发能向PSⅡ传递。在籼稻中激发峰和发射峰以及相关比值在受到高光胁迫后下降的幅度均比在粳稻中显著。与粳稻相比 ,高光胁迫几乎使籼稻的PSⅡ捕光色素蛋白复合体的三聚体解体 ,使其PSⅡ捕光色素蛋白复合体的二聚体、PSⅡ内周天线色素蛋白复合体、PSⅠ捕光色素蛋白复合体以及PSⅠ反应中心叶绿素a蛋白复合体的含量明显降低。高光胁迫导致水稻两亚种的PSⅡ捕光色素蛋白复合物单体含量的增加。类囊体膜多肽分析表明 ,高光胁迫使属于PSⅡ捕光色素蛋白复合体的 2 7、2 5kD蛋白和PSⅠ捕光色素蛋白复合体的 2 1kD蛋白含量在水稻两亚种中都降低 ,其中以 2 5kD蛋白含量降幅最大。在籼稻中高光胁迫使属于PSⅡ内周天线色素蛋白复合体的 43kD和 47kD蛋白以及外周 2 3kD蛋白含量明显降低而在粳稻中则影响较小。
基金
TheStateKeyBasicResearchandDevelopmentPlan (G19980 10 10 0 )
TheInnovativeFoundationofLaboratoryofPhotosynthesisBasicRe searc
