Molecular phylogeny and expression of poplar circadian clock genes, LHY1 and LHY2
Molecular phylogeny and expression of poplar circadian clock genes, LHY1 and LHY2
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DOI：
10.1111/j.1469-8137.2008.02714.x
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发表时间：
2009-01-01
期刊：
影响因子：
9.4
通讯作者：
Uemura, Matsuo
中科院分区：
文献类型：
--
作者：
Takata, Naoki;Saito, Shigeru;Uemura, Matsuo
LHY/CCA1基因在植物生物钟系统中起着关键作用，在植物中高度保守。然而，LHY/CCA1基因家族在被子植物中的进化过程尚不清楚。本研究以模式木本植物杨树为材料，通过外显子-内含子结构比较、系统发育树重建和同线关系检验三种方法对被子植物LHY/CCA1基因的进化过程进行了研究，以获得这些基因的系统发育细节。此外，还分析了杨树LHY的分子进化速率和表达模式。杨树LHY和拟南芥LHY/CCA1的基因复制事件是由各自进化谱系中出现的不同染色体复制事件独立发生的。通过估计这些基因的替换率，对杨树LHY进行了净化选择。此外，杨树LHY基因在叶和茎中的表达具有较强的保守性，但在植物中LHY2的转录本比LHY1基因的转录本更为丰富。此外，LHY1杨和LHY2杨的转录本丰度和进化差异表明，LHY2杨而不是LHY1杨在杨树时钟系统中发挥着重要作用。
LHY/CCA1 genes play a key role in the plant circadian clock system and are highly conserved among plant species. However, the evolutionary process of the LHY/CCA1 gene family remains unclear in angiosperms. To obtain details of the phylogeny of these genes, this study characterized LHY/CCA1 genes in a model woody plant, Populus tree.The evolutionary process of angiosperm LHY/CCA1 genes was elucidated using three approaches: comparison of exon-intron structures, reconstruction of phylogenetic trees and examination of syntenic relationships. In addition, the molecular evolutionary rates and the expression patterns of Populus LHYs were analyzed.Gene duplication events of Populus LHYs and Arabidopsis LHY/CCA1 had occurred independently by different chromosomal duplication events arising in each evolutionary lineage. Populus LHYs were under purifying selection by estimating substitution rates of these genes. Further, Populus LHYs conserved diurnal expressions in leaves and stems but the transcripts of LHY2 were more abundant than those of LHY1 in Populus plants.This study uncovered phylogenetic relationships of the LHY/CCA1 gene family in angiosperms. In addition, the transcript abundance and the evolutionary differences between Populus LHY1 and LHY2 imply that Populus LHY2, rather than LHY1, may have a major role in the Populus clock system.New Phytologist (2009) 181: 808-819doi: 10.1111/j.1469-8137.2008.02714.x.