摘要
以鱼腥藻为材料 ,研究了外源Ca2 +对模拟微重力环境中微藻细胞膜透性的影响。实验结果表明 :提高培养基中的Ca2 +浓度可减轻由模拟微重力造成的膜透性增大 ,有助于稳定细胞膜结构和功能。同时 ,外源Ca2 +降低了藻细胞光系统Ⅱ (PSⅡ )的光化学效率 (以荧光参数Fv/Fm表示 )下降的幅度 ,表明外源Ca2 +对模拟微重力环境下鱼腥藻细胞光合作用的损伤 ,有良好的防护效应。
In this study, the effects of exogenous Ca 2+ on the membrane permeability and photosynthetic characteristics of Anabaena sp.PCC7120 cells under simulated microgravity were studied. Simulated microgravity was provided by a slowly horizontal rotating clinostat. Physiological characteristics of Anabaena sp.PCC7120 cells in three different content of Ca 2+ were measured. During 72h of treatment, the membrane permeability of Anabaena sp.PCC7120 cells was higher 16% in Ca 2+-free medium than that in the control (0.245mmol/L), and higher 45% than that in medium of high concentration of Ca 2+ (0.490mmol/L). The photochemistry efficiency (expressed as Fv/Fm) of Anabaena sp.PCC7120 cells decreased under simulated microgravity, but the range of decreasing was different in three different treatments. In Ca 2+-free medium, the value of Fv/Fm quickly decreased at the first day, and the decreasing range reached 35% at the third day. However, in the Ca 2+-complete medium, the value of Fv/Fm decreased slowly. With increasing concentration of Ca 2+ in medium, the decreasing range was only 26% in medium of high concentration of Ca 2+(0.490mmol/L) at the end of experiments. The treatment with Ca 2+ channel inhibitor showed that the second messenger was involved in the protective process. Experimental results showed that increased Ca 2+ in medium could alleviate membrane permeability induced by simulated microgravity, and lessened the decreasing range of photochemistry efficiency in Anabaena sp.PCC7120 cells. Exogenous Ca 2+ might enhance stabilization of plasma membrane. Moreover, exogenous Ca 2+ might alleviate the microgravity-induced damage of photosynthesis of Anabaena sp.PCC7120 cells.
出处
《水生生物学报》
CAS
CSCD
北大核心
2003年第2期136-139,共4页
Acta Hydrobiologica Sinica
基金
92 1国家载人航天工程项目资助
