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渗透胁迫对高梁根K~(+)吸收的影响

乙引, 汤章城

中科院上海植物生理研究所.上海200032

摘要

以CaSO_(4)0.5mmolL~(-1)溶液培养高梁到低钾植株,在渗透胁迫下当PEG-1000使外界渗透势下降时,刺激了高粱根K~(+)亲和系统的净K~(+)积累,其表观K_(m)值和V_(max)值分别为18#mu#mol L~(-1)和49.6#mu#molg~(-1)DWh~(-1)。此高亲和系统不受可渗物质乙二醇和外界pH变化的影响,蛋白质合成抑制剂环己酰亚胺抑制。

关键词： 渗透胁迫; 高粱根; 钾吸收; H~(+)分泌

Effects of osmotic stress on K~(+) uptake in sorghum roots

Yi Yin, Tang Zhangcheng

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

Abstract

Low K~(+) sorghum plants were cultured in 0.5 mmol L~(-1) CaSO_(4) solution.The low K~(+) roots of these plants had two K~(+) uptake systems: a high-affinity component and a linearlow-affinity component. A decrease of the external osmotic potential, caused by PEG-1000 solution,simulated K~(+) accumulation completed by a new transport system with appearant K_(m) and V_(max) values of 18 #mu#mol L~(-1) and 49.6 #mu#molg~(-1)DWh~(-1),respectively.The relationship between H~(+) efflux and K~(+) accumulation showed that the high-affinity system was driven directly by ATP,while the low-affinity system was coupled to H~(+) extrusion.The inhibition of this process by cycloheximide,indicated that the high-affinity component was formed through de novo synthesis under PEG-1000 stress.Therefore,it is suggested that osmotic stress can induce the formation of a high-affinity K~(+) transport system.

Key words: Osmotic stress;Sorghum roots;K~(+) uptake;H~(+)secretion

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引用本文：

乙引, 汤章城. 渗透胁迫对高梁根K~(+)吸收的影响[J]. 生理学报 1996; 48 (2): .

Yi Yin, Tang Zhangcheng. Effects of osmotic stress on K~(+) uptake in sorghum roots. Acta Physiol Sin 1996; 48 (2): (in Chinese with English abstract).