遗传 ›› 2013, Vol. 35 ›› Issue (5): 655-665.doi: 10.3724/SP.J.1005.2013.00655

• 研究报告 • 上一篇    下一篇

拟南芥AtGA3OX1AtGA3OX2基因影响茎秆次生细胞壁增厚的分子机理

王增光1,2, 柴国华2, 王芝瑶1, 2, 唐贤丰2, 孙长江3, 周功克2, 马三梅1   

  1. 1. 暨南大学生命科学技术学院生物工程学系, 广州 510632 2. 中国科学院青岛生物能源与过程研究所, 青岛 266103 3. 北京旭阳化工技术研究院有限公司, 北京 100070
  • 收稿日期:2012-11-25 修回日期:2013-01-21 出版日期:2013-05-20 发布日期:2013-05-25
  • 通讯作者: 马三梅 E-mail:msmwdw@163.com
  • 基金资助:

    中国科学院知识创新工程项目(编号:KSCX2-EW-J-10)和中科院“百人计划”项目(编号:428)资助

Molecular mechanism of AtGA3OX1 and AtGA3OX2 genes affecting secondary wall thickening in stems in Arabidopsis

WANG Zeng-Guang1,2, CHAI Guo-Hua2, WANG Zhi-Yao1,2, TANG Xian-Feng2, SUN Chang-Jiang3, ZHOU Gong-Ke2, MA San-Mei1   

  1. 1. Department of Biotechnology, School of Life Science and Technology, Jinan University, Guangzhou 510632, China 2. Qingdao Institute Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266103, China 3. Beijing Risun Chemical Industry Technology Research Institute Co. Ltd, Beijing 100070, China
  • Received:2012-11-25 Revised:2013-01-21 Online:2013-05-20 Published:2013-05-25

摘要: 赤霉素不仅对植物的种子萌发、叶片伸展和开花结果有重要的影响, 而且在茎秆的发育过程中扮演关键的角色。它的生物合成受到多种酶的调控, 其中赤霉素3-氧化酶(GA3OX)是关键的限速酶, 备受重视。拟南芥AtGA3OX 基因由4个成员组成, 其中A3OX1AtGA3OX2 基因在茎中超量表达, 可能与茎的发育有关。目前, 尚未见到AtGA3OX1、AtGA3OX2基因调控次生细胞壁增厚的报道。文章以拟南芥AtGA3OX1AtGA3OX2 基因双突变体atga3ox1atga3ox2为材料, 系统研究了AtGA3OX1和AtGA3OX2 基因对次生细胞壁的影响。结果表明:同时突变 AtGA3OX1AtGA3OX2基因不仅显著抑制了茎秆次生细胞壁纤维细胞的增厚(对导管细胞没有影响), 而且也明显降低了次生细胞壁3个组分(纤维素、半纤维素和木质素)的含量。利用实时荧光定量PCR (qRT-PCR) 进一步分析次生细胞壁3个组分生物合成基因及相关的转录因子的表达情况, 结果显示这些基因在双突变体中均受到显著影响, 表明拟南芥AtGA3OX1AtGA3OX2 基因可能是通过调控这些转录因子进而调控了次生细胞壁的加厚。研究结果为基因工程调控拟南芥AtGA3OX1、AtGA3OX2 基因(或其他物种同源基因), 进而增强粮食作物抗倒伏性和提高能源植物纤维生物质量提供了理论依据。

关键词: AtGA3OX, 拟南芥, 次生细胞壁, 转录因子

Abstract: Bioactive gibberellins (GAs) are a type of important plant growth regulators, which play the key roles in multiple processes, such as seed germination, leaf expansion, flowering, fruit bearing, and stem development. Its biosynthesis is regulated by a variety of enzymes including gibberellin 3-oxidase that is a key rate-limiting enzyme. In Arabidopsis, gibberellin 3-oxidase consists of four members, of which AtGA3OX1 and AtGA3OX2 are highly expressed in stems, suggesting the potential roles in the stem development played by the two genes. To date, there are few studies on AtGA3OX1 and AtGA3OX2 regulating secondary wall thickening in stems. In this study, we used the atga3ox1atga3ox2 double mutant as the materials to study the effects of AtGA3OX1 and AtGA3OX2 genes on secondary wall thickening in stems. The results indicated that simulations repression of AtGA3OX1 and AtGA3OX2 genes resulted in significantly reduction of secondary wall thickening of fiber cells, but not that of ves-sel cells. Three main components (cellulose, hemicelluloses, and lignin) were also dramatically suppressed in the double mutants. qRT-PCR analysis demonstrated that the expressions of secondary wall biosynthetic genes and the associated tran-scription factors were obviously affected in AtGA3OX1 and AtGA3OX2 double mutant. Therefore, we pre-sume that Arabidopsis AtGA3OX1 and AtGA3OX2 genes might activate the expression of these transcription factors, thus regulate secondary wall thickening in stems. Together, our results provide a theoretical basis for enhancing the lodging resistance of food crops and improving the biomass of energy plants by genetically engineering Arabidopsis AtGA3OX homologs.

Key words: secondary wall, transcription factor, AtGA3OX, Arabidopsis