Redundancy and metabolic function of the glutamine synthetase gene family in poplar.
Redundancy and metabolic function of the glutamine synthetase gene family in poplar.
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DOI：
10.1186/s12870-014-0365-5
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发表时间：
2015-01-22
影响因子：
5.3
通讯作者：
Cánovas FM
中科院分区：
文献类型：
--
作者：
Castro-Rodríguez V;García-Gutiérrez A;Cañas RA;Pascual MB;Avila C;Cánovas FM
谷氨酰胺合成酶（Glutamine synthetase，GS; EC：6.3.1.2，L-glutamate：ammonia ligase ADP-forming）是高等植物中氨同化和代谢的关键酶。在白杨中，GS家族由4组重复基因组成，其中3组编码胞质GS亚型（GS 1.1、GS 1.2和GS 1.3），一组编码脉络GS亚型（GS 2）。我们以前的工作表明，GS重复可能已被保留，以增加特定细胞类型中的酶的量。本研究旨在通过对白杨GS同工酶的分子生物学特性和动力学参数的测定来验证这一假说。为进一步了解GS基因的功能，采用原位杂交技术和激光捕获显微切割技术，对杨树不同组织进行了GS基因的原位杂交和激光捕获显微切割，并确定了GS基因在叶、茎和根的特定细胞/组织类型中的精确表达模式。白杨GS家族的分子和功能分析以及相应mRNA在不同细胞类型中的精确定位强烈表明，GS异构体在白杨生物学中发挥非冗余作用。此外，我们的研究结果支持这样的建议，即在特定的细胞/组织类型中重复的基因的功能是增加酶的丰度。综上所述，我们的研究结果表明，在整个植物水平上，白杨GS家族没有冗余，但它存在于特定的细胞类型中，其中两个重复的基因表达，其基因表达产物具有相似的代谢作用。基因冗余可能有助于氮代谢的稳态功能与环境条件和发育阶段的变化。本文的在线版本（doi：10.1186/s12870-014-0365-5）包含补充材料，可供授权用户使用。
Glutamine synthetase (GS; EC: 6.3.1.2, L-glutamate: ammonia ligase ADP-forming) is a key enzyme in ammonium assimilation and metabolism in higher plants. In poplar, the GS family is organized in 4 groups of duplicated genes, 3 of which code for cytosolic GS isoforms (GS1.1, GS1.2 and GS1.3) and one group that codes for the choroplastic GS isoform (GS2). Our previous work suggested that GS duplicates may have been retained to increase the amount of enzyme in a particular cell type. The current study was conducted to test this hypothesis by developing a more comprehensive understanding of the molecular and biochemical characteristics of the poplar GS isoenzymes and by determinating their kinetic parameters. To obtain further insights into the function of the poplar GS genes, in situ hybridization and laser capture microdissections were conducted in different tissues, and the precise GS gene spatial expression patterns were determined in specific cell/tissue types of the leaves, stems and roots. The molecular and functional analysis of the poplar GS family and the precise localization of the corresponding mRNA in different cell types strongly suggest that the GS isoforms play non-redundant roles in poplar tree biology. Furthermore, our results support the proposal that a function of the duplicated genes in specific cell/tissue types is to increase the abundance of the enzymes. Taken together, our results reveal that there is no redundancy in the poplar GS family at the whole plant level but it exists in specific cell types where the two duplicated genes are expressed and their gene expression products have similar metabolic roles. Gene redundancy may contribute to the homeostasis of nitrogen metabolism in functions associated with changes in environmental conditions and developmental stages. The online version of this article (doi:10.1186/s12870-014-0365-5) contains supplementary material, which is available to authorized users.
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影响因子：
4.3
作者：
CANOVAS, FM;CANTON, FR;DEVICENTE, A
通讯作者：
DEVICENTE, A
影响因子：
7.2
作者：
Gómez-Maldonado, J;Avila, C;Campbell, MM
通讯作者：
Campbell, MM
影响因子：
9.4
作者：
Jing, ZP;Gallardo, F;Cánovas, FM
通讯作者：
Cánovas, FM
影响因子：
4.9
作者：
Ishiyama, K;Inoue, E;Takahashi, H
通讯作者：
Takahashi, H
Populus中的谷氨酰胺合成酶基因家族。
影响因子：
5.3
作者：
Castro-Rodríguez V;García-Gutiérrez A;Canales J;Avila C;Kirby EG;Cánovas FM
通讯作者：
Cánovas FM