不同生境下木麻黄脯氨酸含量和质膜ATPase活性的研究

采集生长于恶劣环境和中生环境的普通木麻黄(Casuarina)小枝,超速离心提取粗质膜制剂后,用两相系统法纯化得到质膜微囊,研究不同生境下木麻黄的质膜ATPase活性,并测定木麻黄小枝的游离脯氨酸含量。实验结果表明:同一生境中的木麻黄ATPase活性相对一致,而同一树种木麻黄不同生境下质膜微囊H~+-ATPase、Ca~(2+)-ATPase、K~+-ATPase活性有显著差异,表现出以渗透胁迫为主的恶劣环境下的木麻黄质膜微囊ATPase活性和木麻黄细胞内游离脯氨酸明显高于中生环境下生长的木麻黄。说明普通木麻黄在干旱和盐胁迫下能调整生理生化过程来提高其质膜ATPase活性和增加细胞内脯氨酸含量提高渗透调节能力以保证其在恶劣环境的正常生长。

CHANGES OF PLASMA MEMBRANE ATPase ACTIVITIES AND PROLINE ACCUMULATION IN TWIGS OF CASUARINA UNDER DIFFERENT GROWTH CONDITIONS

Twigs of Casuarina were collected from Dongshan and Xiamen Island, China. Crude plasma membrane preparation was obtained from Casuarina twigs by ultra-centrifugation. Sealed plasma membrane vesicles were isolated with aqueous PEG3350-Dextran T500 two phase partitioning. We studied the proline accumulation in twigs and the ATPase activities of plasma membrane of Casurina under different growth conditions. The results showed that free proline content and the PM ATPase activities from unfavorable growth conditions were obviously higher than those from favorable environment. This suggested that Casuarina responded to osmotic stress by increasing osmotic material content and the proton transportation activities of PM ATPase.