《植物生理学报》 2013, 49(4): 375-384

Zn胁迫下小麦S-腺苷甲硫氨酸代谢途径关键基因表达模式分析

柴兴苹¹, 张玉秀², 谭金娟¹, 冯珊珊¹, 柴团耀^1,*

1中国科学院大学生命科学学院, 北京100049; 2中国矿业大学(北京)化学与环境工程学院, 北京100083

通信作者：柴团耀；E-mail: tychai@ucas.ac.cn；Tel: 010-88256343

摘　要：

从Zn胁迫下小麦幼苗的抑制差减杂交(SSH) cDNA文库中筛选出S-腺苷甲硫氨酸(SAM)代谢途径中的9个关键基因,并采用实时荧光定量PCR对其表达模式进行分析。结果表明, Zn (1 mmol·L-1)胁迫下小麦的S-腺苷甲硫氨酸合成酶基因(SAMS)表达呈下降趋势, 而参与谷胱甘肽(GSH)和烟酰胺(NA)合成代谢的关键基因均上调表达; 不同浓度Zn处理4 h后, 小麦SAM代谢途径中基因的快速响应存在差异。可见, Zn胁迫下, 小麦SAM代谢途径中GSH和NA的合成代谢增强, GSH和NA可能参与小麦对Zn胁迫的响应及降低Zn毒害的作用。

关键词：小麦; Zn; S-腺苷甲硫氨酸; 表达模式

收稿：2013-02-01   修定：2013-03-29

资助：转基因生物新品种培育重大专项(2009ZX08009-130B)和中国科学院“十二五”生命科学前沿(KSCX2-EW-J-29)。

Analysis of Expression Patterns of Genes Participated in S-Adenosylmethionine (SAM) Metabolic Pathway in Wheat under Zn Stress

CHAI Xing-Ping¹, ZHANG Yu-Xiu², TAN Jin-Juan¹, FENG Shan-Shan¹, CHAI Tuan-Yao^1,*

¹College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; ²School of Chemical and Environ-mental Engineering, China University of Mining and Technology (Beijng), Beijng 100083, China

Corresponding author: CHAI Tuan-Yao; E-mail: tychai@ucas.ac.cn; Tel: 010-88256343

Abstract:

A suppression subtractive hybridization (SSH) cDNA library of wheat (Triticum aestivum) seedlings under different concentrations of Zn for different treatment time was established and several genes involved in the metabolic pathway of S-adenosylmethionine (SAM) were selected. To clarify the relationship between SAM metabolic pathway and response of wheat to Zn stress, the expression levels of nine genes participated in SAM metabolic pathway were analysed by real-time quantitative PCR. The results showed that SAMS was down-regulated in both shoots and roots of wheat after exposed to Zn (1 mmol·L-1) stress; while SAHase, γ-ECS, GST, NAS3 and NAAT were up-regulated under identical treatment. Expression patterns of SAM metabolism genes in wheat under low Zn concentration (0.5 mmol·L-1) were different from those under high Zn concentration (5 mmol·L-1). These results suggest that synthesis of glutathione (GSH) and nicotianamine (NA) in SAM metabolic pathway in wheat are enhanced under Zn stress. Thus, GSH and NA may play significant roles in the response of wheat to Zn stress and reduce Zn toxicity.

Key words: wheat; Zn; S-adenosylmethionine; expression pattern