Isolation and characterization of chloroplastic glutamine synthetase gene (CsGS2) in tea plant Camellia sinensis
Isolation and characterization of chloroplastic glutamine synthetase gene (CsGS2) in tea plant Camellia sinensis
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茶树叶绿体谷氨酰胺合成酶基因(CsGS2)的分离与鉴定
DOI：
10.1016/j.plaphy.2020.07.042
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发表时间：
2020
影响因子：
6.5
通讯作者：
Jianyun Ruan
中科院分区：
文献类型：
--
作者：
D;an Tang;Mei-Ya Liu;Qunfeng Zhang;Kai Fan;Jianyun Ruan
茶树(Camellia Sinensis)是喜铵植物。然而，人们对这种偏好背后的机制知之甚少。本研究从茶树品种C中分离到一个叶肉组织氮素同化过程中起重要作用的叶绿体谷氨酰胺合成酶基因(CsGS2)。辛西斯卡。《龙井43号》。CsGS2的全长为1622bp，开放阅读框为1299bp，编码432个氨基酸。同源性搜索和序列分析表明，CsGS2蛋白具有典型的GS2结构域的基本特征，并与其他植物的GS2蛋白有很高的同源性。CsGS2的亚细胞定位和免疫定位表明它定位于叶绿体中。QRT-PCR和Western印迹分析表明，CsGS2以叶片特异的方式表达，CsGS2及其蛋白在成熟叶片中含量最高。CsGS2的时间表达模式对氨氮和硝酸盐营养的响应略有不同。在新梢发育过程中，CsGS2的转录水平在成熟叶片中显著诱导，而黑暗则显著抑制这种诱导。这些结果表明，CsGS2在茶树不同氮素形态的差异利用机制中不起作用，并暗示在新梢发育过程中成熟叶片的转录调控是光依赖的。
Tea plant (Camellia sinensis) is an ammonium preferring plant species. However, little is known about the mechanism underlying this preference. Herein, a chloroplastic glutamine synthetase gene (CsGS2), which is vital for nitrogen assimilation in mesophyll tissue, was isolated from tea cultivarC. sinensiscv. ‘Longjing43’. The full length cDNA ofCsGS2was 1622 bp, having a 1299 bp open reading frame encoding a 432-amino acid protein. Homology search and sequence analysis demonstrated that CsGS2 protein carried the basic characteristics of a canonical GS2 domain and shared high identity with GS2s from other plant species. Subcellular localization and immunolocalization of CsGS2 revealed that it is localized in chloroplast. qRT-PCR and Western blot analyses showed thatCsGS2was expressed in a leaf-specific pattern, such that bothCsGS2and its protein were most abundant in mature leaves. Temporal expression patterns ofCsGS2showed minor differences in response to ammonium and nitrate nutrition. The transcript level ofCsGS2was significantly induced in mature leaves during the development of new shoots, whereas darkness inhibited this induction significantly. These results suggested thatCsGS2does not play a role in the differential utilization mechanisms of differing nitrogen forms in tea, and imply a light dependent transcription regulation in mature leaves during the development of new shoots.