Journal of Integrative Agriculture ›› 2021, Vol. 20 ›› Issue (6): 1515-1524.DOI: 10.1016/S2095-3119(20)63305-6

所属专题: 园艺-分子生物合辑Horticulture — Genetics · Breeding

• 论文 • 上一篇    下一篇

  

  • 收稿日期:2020-02-20 出版日期:2021-06-01 发布日期:2021-05-19

Functional analysis of the nitrogen metabolism-related gene CsGS1 in cucumber

XIN Ming1, QIN Zhi-wei1, YANG Jing1, ZHOU Xiu-yan1, WANG Lei2
 
  

  1. 1 College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin 150030, P.R.China
    2 College of Resources and Environment, Northeast Agricultural University, Harbin 150030, P.R.China
  • Received:2020-02-20 Online:2021-06-01 Published:2021-05-19
  • Contact: Correspondence QIN Zhi-wei, E-mail: gsgast@126.com
  • About author:XIN Ming, E-mail: xinmingneaut@126.com
  • Supported by:
    We acknowledge the funding support from Heilongjiang Postdoctoral Scientific Research Developmental Fund, China (LBH-Q16021), “Academic Backbone” Project of Northeast Agricultural University, China (18XG06), the National Science Foundation of Heilongjiang Province, China (LH2019C033).

摘要:

本研究深入分析了在不同氮依赖黄瓜品种的叶片中CsGS1相对表达模式,并对CsGS1蛋白进行亚细胞定位。结果表明,低氮依赖品种D0328在叶片中特异性地高表达CsGS1,而高氮依赖品种D0422的叶片、茎和根中CsGS1的表达量没有明显差异。GS1蛋白定位于细胞质上,为细胞质蛋白。进一步将CsGS1转化到两个黄瓜品种D0328和D0422中,过量表达CsGS1可显著提高黄瓜植株的光合参数、植株鲜重、株高、根长、叶绿素b含量、植株总氮量以及GS活性等指标,反义表达CsGS1使这些指标水平显著降低。黄瓜CsGS1能够响应低氮胁迫,提高黄瓜植株对低氮的耐受性,因此CsGS1的高效表达可以作为提高黄瓜氮素利用效率的潜在育种目标。


Abstract:

Glutamine synthetase (GS) plays an important role in nitrogen (N) metabolism in cucumber.  In this study, we cloned and sequenced the CsGS1 gene, and analyzed the expression patterns and subcellular localization of the GS1 protein in response to different N conditions in order to determine its role in low-nitrogen (LN) tolerance.  CsGS1 was abundantly expressed in the leaves of the low N-requiring cultivar D0328, while the high N-requiring cultivar D0422 showed similar expression levels across different tissues including leaves, shoots and roots.  Furthermore, the GS1 protein was primarily localized in the cytoplasm of plant cells.  Both cultivars were then transformed with the CsGS1 coding sequence or antisense sequence via Agrobacterium tumefaciens in order to overexpress and silence GS1 expression, respectively.  Overexpression of CsGS1 significantly improved LN tolerance and photosynthetic parameters, and increased chlorophyll b content, biomass, plant height, root length, N accumulation and GS activity under LN condition compared to the control.   CsGS1 silencing on the other hand significantly reduced the above indices.  Taken together, CsGS1 is crucial for maintaining N metabolism in cucumber plants during N deprivation, and is a promising target for generating novel transgenic breeds with increasing nitrogen utilization efficiency. 

Key words: cucumber ,  CsGS1 ,  low nitrogen ,  functional verification