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拟南芥ABA不敏感型突变体及其ABA结合特性

郑慧琼, 陈季楚, 赵毓橘, 许智宏

中科院上海植物生理研究所. 上海 200032

摘要

拟南芥的脱落酸(ABA)不敏感型突变体abi2,在对ABA的敏感性、气孔开度及种子休眠方面, 与野生型有明显差异。通过~(3)H-ABA 与野生型叶的亚细胞组分的结合分析,表明38 000×g组分特异结合活性最高,结合最适温度为20℃,最适保温时间:20℃时为70 min; 0℃时为90 min。由饱和曲线的Scatchard分析表明:abi2存在一种ABA结合位点,野生型有两种ABA结合位点。对~(3)H-ABA结合的38 000×g组分的SDS-PAGE电泳分析表明:野生型有3个结合活性峰, 而 abi2只有1个结合活性峰。

关键词： 脱落酸; 拟南芥; 不敏感型突变体; 结合位点

Characterization of ABA binding in ABA-insensitive mutant abi2 of Arabidopsis thaliana

Zhena Huiqiong, Chen Jichu, Zhao Yuju, Xu Zhihong

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

Abstract

There are distinct differences in physiological characteristics,such as seed domancy, sensitivity to ABA and aperture of the stomata between wild-type and the ABA-insensitive mutant abi2 from Arabidopsis thaliana (Landsberg) ~(3)H-ABA binding in subcellular fractions(4 000-100 000×g) of wild-type and abi2 showed that the strongest specifically-bound activity was in the 38 000×g pellet fraction, the optimum temperature of ABA binding was 20℃. Scatchard plot ofsaturation kinetics showed that there was one kind of binding site in abi2, but two in wild-type. By analysis of electropherogram on SDS-PAGE of~(3)H-ABA-labelled 38 000×g fractions from leaves of abi2 and wild-type,three peaks of ~(3)H-ABA-binding activity were found in wild-type, but only one in abi2.These results suggest that the insensitivity to ABA of abi2 might be caused by mutation of ABA-binding sites.

Key words: Abscisic acid;Arabidopsis thaliana;Insensitive mutunt;Binding site

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引用本文：

郑慧琼, 陈季楚, 赵毓橘, 许智宏. 拟南芥ABA不敏感型突变体及其ABA结合特性[J]. 生理学报 1997; 49 (2): .

Zhena Huiqiong, Chen Jichu, Zhao Yuju, Xu Zhihong. Characterization of ABA binding in ABA-insensitive mutant abi2 of Arabidopsis thaliana. Acta Physiol Sin 1997; 49 (2): (in Chinese with English abstract).