《植物生理学报》 2013, 49(1): 89-94

不同酸化条件对菜豆幼苗碳氮代谢酶系活性的影响

孙海燕¹, 郭伟^2,*

黑龙江八一农垦大学1测试中心, 2黑龙江省寒地作物种质改良与栽培重点实验室, 黑龙江大庆163319

通信作者：郭伟；E-mail: agrigw@163.com；Tel: 0459-6819181

摘　要：

采用4个不同pH值(pH 7, 6, 5, 4)培养液模拟菜豆萌发和幼苗生长环境, 研究了酸化条件下菜豆种子萌发和幼苗生长特性、幼苗根系和幼叶的抗氧化酶系活性以及叶片的碳氮代谢的主要酶系活性和产物水平, 以期明确菜豆的碳氮代谢对酸化胁迫的响应机制。结果表明: 随着pH的降低, 菜豆发芽势和发芽率降低, 幼苗和根系干物质量减少; 谷氨酰胺合成酶活性降低, 蔗糖磷酸合成酶活性增强, 从而增加了蔗糖、果糖和总可溶性糖含量; 根系的超氧阴离子自由基(O2 ¯· )和丙二醛(MDA)含量降低, 叶片的O2 ¯·和MDA含量增加, 而叶片和根系的抗氧化酶系活性同向变化, 即超氧化物歧化酶和过氧化氢酶活性增强, 过氧化物酶活性降低。酸化条件下, 菜豆的碳代谢加强, 氮代谢受到抑制; 叶片过氧化物酶活性的降低和O2 ¯·含量的增加, 导致了叶片膜脂过氧化程度的加剧。

关键词：菜豆; 酸化; 碳氮代谢; 抗氧化酶

收稿：2012-11-12   修定：2012-12-23

资助：黑龙江省科技厅课题(GZ11B101)和校博士启动金课题(校启2012DB-02)。

Effects of Acid on Enzyme Activity of Carbon-Nitrogen Metabolic in Kidney Bean Seedling

SUN Hai-Yan¹, GUO Wei^2,*

¹Test Center, ²Key Laboratory of Cold Crop Germplasm Improvement and Cultivation of Heilongjiang Province, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang 163319, China

Corresponding author: GUO Wei; E-mail: agrigw@163.com; Tel: 0459-6819181

Abstract:

Four different pH (pH 7, 6, 5, 4) nutrient solutions were applied to simulate the environment of ger-mination and growth for kidney bean (Phaseolus vulgari L.). Seed germination, seedling growth characteristics, antioxidase enzyme activities of root and leaf and carbon-nitrogen metabolism enzyme activities and product levels of leaf were studied with decreasing pH in order to explain the response mechanism of carbon-nitrogen metabolism to acidification stress for kidney bean. The results showed that germinating potential and germina-tion rate decreased, seedling and root dry weight reduced, and glutamine synthetase (GS) activity decreased and sucrose phosphate synthase (SPS) activity increased which increased the contents of sucrose, fructose and total soluble sugar, decreased the contents of superoxide anion free radical (O2¯·) and malondialdehyde (MDA) of root, and increased the contents of O2¯· and MDA of leaf with decreasing pH. However, the change trend of anti-oxidase in root was the same as that in leaf, namely, the activity of superoxide dismutase (SOD) and catalase (CAT) increased, peroxidase (POD) activity decreased. Carbon metabolism was increased, however, nitrogen metabolism was inhibited under acidification stress, increased O2¯· content and reduced POD activity of leaf re-sulted in the increase of membrane lipid peroxidation.

Key words: Phaseolus vulgari; acidification; carbon-nitrogen metabolism; antioxidase