遗传 ›› 2014, Vol. 36 ›› Issue (10): 1021-1026.doi: 10.3724/SP.J.1005.2014.1021

• 研究报告 • 上一篇    下一篇

玉米新选细胞质雄性不育系小孢子发育的细胞学观察及DNA甲基化分析

张艳花,易洪杨,房明,荣廷昭,曹墨菊   

  1. 四川农业大学玉米研究所,教育部作物基因资源与遗传改良重点实验室,农业部西南玉米生物学及遗传育种重点实验室,成都 611130
  • 收稿日期:2014-01-17 出版日期:2014-10-20 发布日期:2014-10-20
  • 通讯作者: 曹墨菊,教授,研究方向:玉米雄性不育。E-mail: caomj@sicau.edu.cn E-mail:1182550843@qq.com
  • 作者简介:张艳花,硕士研究生,专业方向:玉米细胞质雄性不育。E-mail: 1020452562@qq.com 易洪杨,硕士研究生,专业方向:玉米生物技术育种,E-mail: 1182550843@qq.com 张艳花和易洪杨同为第一作者。
  • 基金资助:
    国家自然科学基金项目(编号:30971794)资助

Cytological observation and DNA methylation analysis of two new cytoplasmic male sterile lines of maize during microsporogenesis

Yanhua Zhang, Hongyang Yi, Ming Fang, Tingzhao Rong, Moju Cao   

  1. Key Laboratory of Crop Genetic Resource and Improvement of Ministry of Education, Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region of Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Chengdu 611130, China
  • Received:2014-01-17 Online:2014-10-20 Published:2014-10-20

摘要: 细胞质雄性不育在高等植物中普遍存在,是杂种优势利用的重要工具,为推动植物杂种优势的利用发挥了重要作用。文章以本课题组前期新选的玉米细胞质雄性不育系A1、A2及保持系18(红)为材料,利用石蜡切片技术对不育材料小孢子发育过程进行细胞学观察,采用高效液相色谱法(HPLC)对不同发育时期的叶片及不同发育时期的雄穗DNA进行甲基化分析,从细胞学和表观遗传学角度了解不育系A1、A2的败育机制。结果表明:不育材料A1、A2小孢子发生败育的主要时期为四分体时期至单核小孢子中期。在不育系A2中还存在另一种败育方式,即在花粉母细胞时期表现出败育特征。甲基化分析结果表明,保持系18(红)的叶片DNA甲基化水平从苗期到拔节期迅速上升,而不育系A1、A2叶片DNA甲基化水平基本保持不变;保持系雄穗DNA甲基化水平表现为从花粉母细胞时期到双核期逐渐升高,而不育材料A1、A2从花粉母细胞时期到双核期的雄穗DNA甲基化水平表现为先上升后下降的趋势,达到最高峰的时期均出现在小孢子发育的四分体时期。从小孢子发育的细胞学观察结果可以发现,小孢子败育的主要时期往往具有较高的甲基化水平,推测DNA甲基化水平变化可能与不育材料A1、A2的花粉败育有关。

关键词: 玉米, 细胞质雄性不育, 细胞学观察, DNA甲基化

Abstract: Cytoplasmic male sterility (CMS) is a widespread phenomenon in higher plants and has been applied in the commercial production of hybrid seeds. Two CMS lines A1 and A2 of maize were obtained previously by a transgenic experiment. In this study, we conducted cytological observation of developmental microspores with CMS line A1, A2 and their maintainer line (18 red) using paraffin section technology. We also analyzed DNA methylation levels at different developmental stages using high performance liquid chromatography (HPLC). Our results showed that the pollen abortion of A1 and A2 mainly happened from the tetrad stage to the middle of mononuclear stage. Another abortive phenomenon found in CMS line A2 occurred at the pollen mother cell stage. The DNA methylation level of leaf increased rapidly from the seedling stage to the shooting stage in 18 red, while it remained constant in A1 and A2. For the tassel, the DNA methylation levels in 18 red increased gradually during the anther development, while a peak of DNA methylation level occurred in A1 and A2 at the tetrad stage, corresponding to the abortion period of microspore. This result suggested that the level of DNA methylation in the tassels is associated with the pollen abortion characteristics in CMS lines. In summary, our results implied a connection between pollen abortion and epigenetic regulation in maize CMS.

Key words: maize, cytoplasmic male sterility, cytological observation, DNA methylation