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经渗透胁迫高粱根的质膜囊泡K~(+)-ATP酶及其运输特征

乙引, 汤章城

中科院上海植物生理研究所.上海 200032

摘要

经PEG-1000处理的高粱根,用不连续蔗糖密度梯度制备获得反转密闭的纯化质膜囊泡,显示一种特殊的ATP酶活力,它不同于H~(+)-ATP酶,其最适pH为7.5,具有高ATP亲和力和较低的K~(+)转运能力。环己酰亚胺和钒酸钠能抑制其活力,表明它是新合成的P-型ATP酶。

关键词： 高粱根; 质膜囊泡; K~(+)－ATP酶; 渗透胁迫

K~(+)-ATPase and its transport characterization of plasma membrane vesicles from sorghum roots after osmotic stress

Yi Yin, Tang Zhangcheng

Shanghai Institute of Plant Physiology,The Chinese Academy of Sciences.Shanghai 200032

Abstract

Sealed inside-out plasma membrane vesicles prepared by step sucrose gradient from sorghu (Sorghum vulgare L. Jinza No. 5) roots were used to study ATPase activity and K~(+) transport across the membrane. In the absence of Mg~(2+), PM ATPase shoed a pH optimum of 7.5 under PEG-1000 stress. It was unlike plant PM H~(+)-ATPase which need Mg~(2+) and had an optimum pH value of 6.5. Further research proved that the ATPase had a highaffinity for ATP and a low K~(+) transport rate which was not related to H&&~(+)&& transport. The inhibition of its activity by cycloheximide and vanadate showed that it was a P-type ATPase synthesized de novo under osmotic stress. Basing on these observations we conclude that the ATPase is a primary ion-motive K~(+)-ATPase induced by osmotic stress.

Key words: Sorghum root;Plasma membrane vesicles;K~(+)-ATPase;Osmotic stress

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引用本文：

乙引, 汤章城. 经渗透胁迫高粱根的质膜囊泡K~(+)-ATP酶及其运输特征[J]. 生理学报 1996; 48 (3): .

Yi Yin, Tang Zhangcheng. K~(+)-ATPase and its transport characterization of plasma membrane vesicles from sorghum roots after osmotic stress. Acta Physiol Sin 1996; 48 (3): (in Chinese with English abstract).