Li Yueying, He Liangliang, Li Jing, Chen Jianghua, Liu Changning
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla County, China.
Front Plant Sci. 2018 Sep 19;9:1332. doi: 10.3389/fpls.2018.01332. eCollection 2018.
The BRASSINAZOLE-RESISTANT (BZR) family of transcription factors (TFs) are positive regulators in the biosynthesis of brassinosteroids. The latter is a class of steroid hormones that affect a variety of developmental and physiological processes in plants. BZR TFs play essential roles in the regulation of plant growth and development, including multiple stress-resistance functions. However, the evolutionary history and individual expression patterns of the legume genes has not been determined. In this study, we performed a genome-wide investigation of the gene family in seven legume species. In total, 52 genes were identified and characterized. By analyzing their phylogeny, we divided these genes into five groups by comparison with orthologs/paralogs in . The intron/exon structural patterns and conserved protein motifs of each gene were analyzed and showed high group-specificities. Legume genes were unevenly distributed among their corresponding genomes. Genome and gene sequence comparisons revealed that gene expansion of the BZR TF family in legumes mainly resulted from segmental duplications and that this family has undergone purifying selection. Synteny analysis showed that genes tended to localize within syntenic blocks conserved across legume genomes. The expression patterns of genes among various legume vegetative tissues and in response to different abiotic stresses were analyzed using a combination of public transcriptome data and quantitative PCR. The patterns indicated that many genes regulate legume organ development and differentiation, and significantly respond to drought and salt stresses. This study may provide valuable information for understanding the evolution of gene structure and expression, and lays a foundation for future functional analysis of the legume genes by species and by gene.
抗油菜素唑（BZR）转录因子家族是油菜素类固醇生物合成中的正调控因子。后者是一类类固醇激素，影响植物的多种发育和生理过程。BZR转录因子在植物生长发育调控中发挥着重要作用，包括多种抗逆功能。然而，豆科植物BZR基因的进化历史和个体表达模式尚未确定。在本研究中，我们对7种豆科植物的BZR基因家族进行了全基因组调查。共鉴定并表征了52个BZR基因。通过分析它们的系统发育，与拟南芥中的直系同源基因/旁系同源基因比较，我们将这些BZR基因分为五组。分析了每个基因的内含子/外显子结构模式和保守蛋白基序，结果显示出高度的组特异性。豆科植物BZR基因在其相应基因组中分布不均。基因组和基因序列比较表明，豆科植物中BZR转录因子家族的基因扩增主要源于片段重复，并且该家族经历了纯化选择。共线性分析表明，BZR基因倾向于定位在豆科植物基因组中保守的共线性区域内。利用公开的转录组数据和定量PCR相结合的方法，分析了BZR基因在各种豆科植物营养组织中的表达模式以及对不同非生物胁迫的响应。这些模式表明，许多BZR基因调控豆科植物器官的发育和分化，并对干旱和盐胁迫有显著响应。本研究可能为理解BZR基因结构和表达的进化提供有价值的信息，并为未来按物种和基因对豆科植物BZR基因进行功能分析奠定基础。
