光氧化条件下碳代谢中间产物与光合电子传递对PSII光化学活性的调节作用  

The Modulation of PSII Photochemical Activity by Carbon Metabolic Intermediates and Photosynthetic Electron Transport under Photooxidation Conditions

作　　者：林植芳[1] 彭长连[1] 林桂珠[1] 

机构地区：[1]中国科学院华南植物园,广东数字植物园重点实验室,广东广州510650

出　　处：《热带亚热带植物学报》2005年第1期1-7,共7页Journal of Tropical and Subtropical Botany

基　　金：国家自然科学基金(39920019; 30270125)资助

摘　　要：在MV和强光的光氧化条件下研究外加光合碳代谢中间产物、光呼吸C2酸和光合电子传递抑制剂等对菠菜叶绿体PSII光化学活性的调节作用。结果表明, 光氧化条件下外加“RuBP再生系统”和乙醇酸钠可提高qP和ΦPSII,而R5P、DHAP和HCO3ˉ可提高qN,显示其对光氧化下叶绿体PSII活性有一定程度的保护作用。其他外加化合物3-PGA、3-GAP、HPMS、DCMU、DBMIB、Ant A、短杆菌肽D等则对以叶绿素荧光参数表示的光化学活性和氧电极测定的全链电子传递速率表现抑制效应。据此认为在叶绿体水平上阻断或改变光合电子流的流向,更改光合碳还原和光呼吸代谢物浓度,皆可直接或间接影响光氧化下PSII的光化学活性,其作用因不同化合物而异。PSII photochemical activity and electron transport rate of whole chain (PSII+PSI) in spinach chloroplasts were measured under photooxidation (MV plus strong light) with or without addition of various exogenousphotosynthetic carbon metabolic intermediates, Na-glycolate and inhibitors of photosynthetic electron transport. The results indicated that under photooxidation condition, the addition of 'RuBP regeneration system' and sodium glycolate increased qP and ΦPSII, while R5P, DHAP and HCO3ˉ increased qN, compared to nonphoto-oxidative control. Other chemicals, 3-PGA, 3-GAP, HPMS, DCMU, DBMIB, Ant A and gramicidin D all showed an inhibitory effect on PSII photochemical activity (expressed by chlorophyll fluorescence parameters) and electron transport rate of PSII+PSI (determined by oxygen electrode). It is proposed that carbon metabolic intermediate could act as a physiological regulator to modulate PSII photochemical activity. Alteration or blocking the flux /direction of photosynthetic electron transport, and changing the concentration of metabolites in Calvin cycle and photorespiratoy C2 acid cycle would cause a direct or indirect effect on PSII activity under photooxidation condition. The effect varied with different chemicals.

关 键 词：菠菜叶绿体 光氧化 PSⅡ活性 碳代谢中间产物 电子传递 

分 类 号：Q945.78[生物学—植物学]