Rouhier Nicolas, Couturier Jérémy, Jacquot Jean-Pierre
UMR-1136 Interaction arbres microorganismes, INRA, IFR 110, Génomique Ecologie et Ecophysiologie Fonctionnelles, Faculté des Sciences, BP 239, Université Henri Poincaré, F-54506 Vandoeuvre-lès-Nancy Cedex, France.
J Exp Bot. 2006;57(8):1685-96. doi: 10.1093/jxb/erl001. Epub 2006 May 23.
The recent release of the first tree genome (Populus trichocarpa) has allowed a comparison to be made of the multigenic glutaredoxin (Grx) and glutathione reductase (GR) families of this tree with those of other sequenced organisms and especially of the two other fully sequenced plant species, Arabidopsis thaliana and Oryza sativa. Grxs are small proteins involved in disulphide bridge or protein-glutathione adduct reduction, and they are maintained in a reduced form using glutathione and an NADPH-dependent GR. While the P. trichocarpa and O. sativa genomes are nearly five times larger than that of A. thaliana, they contain approximately 45 000 and 37 500 genes compared with the 25 500 genes of A. thaliana. On the one hand, the GR gene composition varies little between species and the gene structures are relatively conserved. On the other hand, the Grx gene family can be divided into three subgroups and the gene content is larger in P. trichocarpa (36 genes) compared with A. thaliana and O. sativa (31 and 27 genes, respectively). This could be partly explained by the occurrence of more duplication events, and this is especially true for one of the three identified Grx subgroups (subgroup III). The expression of most of these genes was confirmed by analysing expressed sequence tags present in various databases. In addition, the expression of Grx of subgroups I and II was examined by RT-PCR in various poplar organs. A complete classification based essentially on gene structure and sequence identity is proposed.
最近公布的首个树木基因组（毛果杨）使得人们能够将该树木的多基因谷氧还蛋白（Grx）和谷胱甘肽还原酶（GR）家族与其他已测序生物的相应家族进行比较，尤其是与另外两个已完成全基因组测序的植物物种——拟南芥和水稻进行比较。Grx是参与二硫键或蛋白质 - 谷胱甘肽加合物还原的小蛋白，它们通过谷胱甘肽和依赖于NADPH的GR维持在还原状态。虽然毛果杨和水稻的基因组大小几乎是拟南芥基因组的五倍，但与拟南芥的25500个基因相比，它们分别含有约45000个和37500个基因。一方面，GR基因组成在不同物种间变化不大，基因结构相对保守。另一方面，Grx基因家族可分为三个亚组，毛果杨中的基因数量（36个基因）比拟南芥和水稻（分别为31个和27个基因）更多。这可能部分是由于发生了更多的复制事件，对于三个已鉴定的Grx亚组之一（亚组III）尤其如此。通过分析各种数据库中存在的表达序列标签证实了这些基因中的大多数的表达。此外，通过RT-PCR在杨树的各种器官中检测了亚组I和II的Grx的表达。提出了一种基本上基于基因结构和序列同一性的完整分类。
