气孔开放过程中苹果酸对保卫细胞磷酸烯醇式丙酮酸羧化酶活性抑制作用的减弱。

Lessened malate inhibition of guard-cell phosphoenolpyruvate carboxylase velocity during stomatal opening.

作者信息

Zhang S Q, Outlaw W H, Chollet R

机构信息

Department of Biological Science, Florida State University, Tallahassee 32306-3050.

出版信息

FEBS Lett. 1994 Sep 19;352(1):45-8. doi: 10.1016/0014-5793(94)00916-3.

DOI:10.1016/0014-5793(94)00916-3

PMID:7925940

Abstract

Leaflets of Vicia faba with closed stomata or with opening stomata were freeze-dried. Excised guard-cell pairs were assayed individually under suboptimal conditions (pH 7.1 and subsaturating substrate) for phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) using quantitative histochemical procedures. L-Malate, 400 microM, significantly inhibited guard-cell PEPC activity of closed stomata but not that of opening stomata. We postulate that the lessened sensitivity of guard-cell PEPC activity to malate inhibition is an important regulatory feature of stomatal opening, which is associated with malate accumulation.

摘要

对具有闭合气孔或正在张开气孔的蚕豆叶片进行冷冻干燥。使用定量组织化学方法，在次优条件（pH 7.1和亚饱和底物）下，对分离出的保卫细胞对进行磷酸烯醇式丙酮酸羧化酶（PEPC；EC 4.1.1.31）分析。400微摩尔的L-苹果酸显著抑制了闭合气孔保卫细胞的PEPC活性，但对正在张开气孔的保卫细胞PEPC活性没有抑制作用。我们推测，保卫细胞PEPC活性对苹果酸抑制的敏感性降低是气孔张开的一个重要调节特征，这与苹果酸积累有关。