Divergence and Conservative Evolution of XTNX Genes in Land Plants.
Divergence and Conservative Evolution of XTNX Genes in Land Plants.
复制标题
陆地植物XTNX基因的分化和保守进化
DOI：
10.3389/fpls.2017.01844
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发表时间：
2017
影响因子：
5.6
通讯作者：
Hang YY
中科院分区：
文献类型：
--
作者：
Zhang YM;Xue JY;Liu LW;Sun XQ;Zhou GC;Chen M;Shao ZQ;Hang YY
Toll白细胞介素1受体（TIR）和核苷酸结合位点（NBS）结构域是TIR-NBS-rich leucine-repeat家族植物抗病基因的两个主要组成部分。对这些基因进行了广泛的功能和进化研究;然而，对由非典型TIR和NBS结构域组成的一小组基因，即XTNX基因的表征是有限的。本研究通过对59个绿色植物基因组进行全基因组分析来研究这一特异基因家族。在52个陆生植物基因组中，有51个基因组中检测到143个XTNX基因，而在所有绿色藻类基因组中均未检测到XTNX基因，表明XTNX基因起源于陆生植物的出现。系统发育分析表明，XTNX基因在陆生植物中经历了两轮古老的复制，先后形成了进化枝I/II和进化枝IIa/IIb。虽然进化枝I和IIb在被子植物中进化保守，但氨基酸水平上的基序组成差异和序列分歧表明，自两个进化枝分离以来可能已经发生了功能分歧。相反，进化枝IIa基因的几个特征，包括在大多数双子叶植物中的缺失，树中的长枝，祖先图案的频繁丢失，以及在玉米的所有检测到的组织中表达的丢失，都表明该谱系中的基因可能经历了假基因化。XTNX基因是一个起源于陆地植物的基因家族，在进化过程中经历了特定的保守模式。
The Toll-interleukin-1 receptor (TIR) and Nucleotide-binding site (NBS) domains are two major components of the TIR-NBS-leucine-rich repeat family plant disease resistance genes. Extensive functional and evolutionary studies have been performed on these genes; however, the characterization of a small group of genes that are composed of atypical TIR and NBS domains, namely XTNX genes, is limited. The present study investigated this specific gene family by conducting genome-wide analyses of 59 green plant genomes. A total of 143 XTNX genes were identified in 51 of the 52 land plant genomes, whereas no XTNX gene was detected in any green algae genomes, which indicated that XTNX genes originated upon emergence of land plants. Phylogenetic analysis revealed that the ancestral XTNX gene underwent two rounds of ancient duplications in land plants, which resulted in the formation of clades I/II and clades IIa/IIb successively. Although clades I and IIb have evolved conservatively in angiosperms, the motif composition difference and sequence divergence at the amino acid level suggest that functional divergence may have occurred since the separation of the two clades. In contrast, several features of the clade IIa genes, including the absence in the majority of dicots, the long branches in the tree, the frequent loss of ancestral motifs, and the loss of expression in all detected tissues of Zea mays, all suggest that the genes in this lineage might have undergone pseudogenization. This study highlights that XTNX genes are a gene family originated anciently in land plants and underwent specific conservative pattern in evolution.
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影响因子：
3.3
作者：
Feng G;Burleigh JG;Braun EL;Mei W;Barbazuk WB
通讯作者：
Barbazuk WB
DOI：
10.1126/science.1236011
发表时间：
2013-08-16
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Dangl JL;Horvath DM;Staskawicz BJ
通讯作者：
Staskawicz BJ
影响因子：
10.7
作者：
Gu, X
通讯作者：
Gu, X
影响因子：
7.2
作者：
Cheng, Chia-Yi;Krishnakumar, Vivek;Town, Christopher D.
通讯作者：
Town, Christopher D.
影响因子：
10.7
作者：
Kumar, Sudhir;Stecher, Glen;Tamura, Koichiro
通讯作者：
Tamura, Koichiro