拟南芥GCR2参与感应N-丁酰基高丝氨酸内酯过程的初步研究

doi:10.13560/j.cnki.biotech.bull.1985.2015.08.014

摘要/Abstract

摘要： N-丁酰基高丝氨酸内酯（C4-HSL）是革兰氏阴性菌主要的群体感应信号,其能促进植物生长发育,激活细胞膜表面的Ca²⁺通道,从而参与调控植物的生理代谢。然而,植物感应C4-HSL的分子机制并不清楚。拟南芥GCR2作为ABA的受体,对植物的生理代谢十分重要。旨在探寻GCR2是否参与拟南芥感应C4-HSL的过程。qRT-PCR结果表明,C4-HSL处理后1 h,GCR2基因表达量出现明显上调并在6 h后达到最大值,说明C4-HSL可调节GCR2。ELISA结果显示,GCR2蛋白表达量也在6 h达到最大值。对体外表达的GCR2进行纯化和浓缩,使其达到0.6 mg/mL后进行微量热泳动（MST）检测。MST测得C4-HSL与GCR2的解离常数（K_d）为166 nmol/L,显示出较强的结合能力。用BSA作为阴性对照,表明C4-HSL与GCR2的结合具有一定的特异性。这些结果表明GCR2可能参与了拟南芥感应C4-HSL的过程。

关键词: 群体感应, N-酰基高丝氨酸内酯, 拟南芥, 微量热泳动

Abstract: N-Butyryl-DL-homoserine lactone（C4-HSL）is a main quorum sensing signal in gram-negative bacteria. It could significantly promote root elongation and activate Ca²⁺ channel at cytomembrane. C4-HSL can regulate metabolization of plant. However, little is known about the molecular mechanism of plants responding to C4-HSL. Arabidopsis thaliana GCR2 is receptor of abscisic acid（ABA）. It is important for metabolization of plant. This research aimed to explore whether the GCR2 is involved in the process of Arabidopsis thaliana reacting to C4-HSL. qRT-PCR showed that C4-HSL could regulate expression of GCR2. Expression of GCR2 was significantly upregulated after 1 h treated by C4-HSL and maximaized at 6 h. ELISA also showed that expression of GCR2 maximaized at 6 h. GCR2 was purified and condensed to 0.6 mg/mL for Microscale Thermophoresis（MST）measurement. MST indicated that dissociation constant（K_d）of GCR2 and C4-HSL was 166 nmol/L, which meant that they had strong binding affinity. Taking BSA as negative control, this certified that binding of GCR2 and C4-HSL had special character. These results showed that Arabidopsis GCR2 maybe involved in the pathway of plant responding to C4-HSL.

Key words: quorum sensing, N-acyl-homoserine lactones, Arabidopsis thaliana, microscale thermophoresis

艾秋实, 张哲, 屈凌波, 刘方, 赵芊, 宋水山. 拟南芥GCR2参与感应N-丁酰基高丝氨酸内酯过程的初步研究[J]. 生物技术通报, 2015, 31(8): 94-101.

Ai Qiushi, Zhang Zhe, Qu Lingbo, Liu Fang, Zhao Qian, Song Shuishan. Preliminarily Research on Involvement of Arabidopsis GCR2 Responsing to N-Butyryl-DL-homoserine Lactone[J]. Biotechnology Bulletin, 2015, 31(8): 94-101.

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