生物学杂志 ›› 2020, Vol. 37 ›› Issue (6): 17-.doi: 10.3969/j.issn.2095-1736.2020.06.017

• 研究报告 • 上一篇    下一篇

不同浓度氮处理对毛果杨天冬氨酸转氨酶酶活性及基因表达的影响

  

  1. 南京林业大学 生物与环境学院 南方现代林业协同创新中心, 南京 210037
  • 出版日期:2020-12-18 发布日期:2020-12-21
  • 通讯作者: 韩梅,副教授,研究方向为植物生化与分子生物学,E-mail:sthanmei@njfu.edu.cn
  • 作者简介:闵杰,硕士,研究方向为植物生化与分子生物学,E-mail:mj12151423@outlook.com
  • 基金资助:
    国家自然科学基金(31700525,31870589);江苏省自然科学基金(BK20170921);江苏高校优势学科建设工程项目(PAPD)

Effects of nitrogen concentrations on enzyme activity and gene expression of aspartate aminotransferase in Populus trichocarpa#br#

  1. College of Biology and the Environment, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
  • Online:2020-12-18 Published:2020-12-21

摘要: 通过对毛果杨设立缺氮(0 mmol/L)、正常氮(2 mmol/L)和高氮(10 mmol/L) 3个氮浓度梯度的处理,利用非变性胶测定PtAspAT酶活性和实时荧光定量PCR检测PtAspAT基因转录本的方法,分析毛果杨不同组织中天冬氨酸转氨酶的酶活性和基因表达量的差异,发现:缺氮会导致毛果杨组培苗幼叶、茎段和根中PtAspAT酶(3种同工酶)活性降低,但成熟叶中其活性基本不受影响;转录水平上大多数PtAspAT基因表达量在缺氮时呈现下降趋势,但PtAspAT1、2、6和7除外,它们的表达量反而有所升高。高氮处理下,茎段和根部的PtAspAT酶(3种同工酶)活性显著提高,但是在叶片中其活性会略微下降;转录水平上除PtAspAT4、5和6在高氮条件下略有降低外,PtAspAT其余各基因表达水平总体提高。PtAspAT线粒体同工酶活性随着氮浓度的增加而提高,然而相应的PtAspAT基因的mRNA表达量与酶活性变化趋势并不一致,表明PtAspAT在植物体内的调控机制比较复杂,可能有转录或翻译后机制参与。研究为进一步深入了解天冬氨酸转氨酶在植物中的生理作用和调控模式奠定了重要基础。

关键词: 毛果杨, 天冬氨酸转氨酶, 氮处理, 基因表达

Abstract: The PtAspATs enzyme activities and their transcripts levels were determined by native gel assay and quantitative real time RT-PCR (qPCR) respectively, in different tissues of Populus trichocarpa exposed to 0 mmol/L, 2 mmol/L and 10 mmol/L nitrogen concentrations. It was found that nitrogen deficiency resulted in the decrease of PtAspAT enzyme (including mitochondria, cytosol and plastid PtAspAT isozymes) activities in young leaves, stem segments and roots, but no significant change in mature leaves; meanwhile, at the transcript level, most of the PtAspAT genes showed a downward expression trend except for PtAspAT1, 2, 6 and 7. Under high nitrogen treatment, the PtAspAT enzyme (including mitochondria, cytosol and plastid PtAspAT isozymes) activities in the stem and root were significantly increased, but which in the leaves were decreased slightly, whereas at the transcript level, most PtAspAT gene transcripts were increased except for PtAspAT4, 5 and 6. Noteworthy, the mitochondria PtAspAT isozyme activities were increased with the increase of nitrogen concentration. However, this change was not coupled with corresponding PtAspATs mRNA, indicating that PtAspATs are subject to a complex regulatory control (e.g. post-transcriptional or post-translational control) in P. trichocarpa. This study would lay an important foundation for further study of the physiological role and regulation mode of aspartate aminotransferase in plants.

Key words: Populus trichocarpa, aspartate aminotransferase, nitrogen treatment, gene expression

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