河北杨CBF类基因的克隆及其进化  

Cloning and Evolution of CBF-like Genes in Populus hopeiensis

作　　者：王泽亮[1] 秦鹏飞 郭洪英[1] 庄国庆[1] 宋跃朋[3] 安新民[3] 张志毅[3] 

机构地区：[1]四川省林业科学研究院,成都610081 [2]宣汉县林业局 [3]林木育种国家工程实验室(北京林业大学)

出　　处：《东北林业大学学报》2013年第10期75-81,共7页Journal of Northeast Forestry University

基　　金：国家“863”项目(2011AA100201);“十二五”科技支撑项目(2012BAD01B0302)

摘　　要：CBF转录因子属于AP2/EREBP转录因子家族,是植物特有的一类转录因子,在植物应对外界非生物胁迫的过程中起了非常重要的作用。在前期克隆河北杨PhCBF4a、PhCBF4b基因的基础上,通过同源克隆方法,从河北杨中继续分离出其它CBF类基因:PhDREB66、PhDREB67-1、PhDREB67-2、PhDREB68、PhDREB69、PhDREB70。与PhCBF4a、PhCBF4b基因相似,这6个基因包含AP2区域、核定位位点(NLS)以及AP2区域侧翼的两个CBF类基因所特有的基序。与相应毛果杨基因比对分析发现,这8个河北杨基因可分为3个Groups(旁系同源基因群),其中2个各包括3个基因,1个包含2个基因,河北杨旁系同源基因及其与毛果杨直系同源物之间在氨基酸水平上表现出了较高的序列一致性。进化分析结果显示,CBF基因可分为真双子叶植物分支与单子叶植物分支。真双子叶植物分支又可以分为3个分支,可分别由3个河北杨CBF旁系同源基因群所代表,显示在从共同的双子叶祖先分离之前或分离过程中,杨树CBF基因经历了复制与趋异的进化过程。PAML分析检测到PhCBF4a基因在进化过程中承受了正向的选择压力,表明其在河北杨响应并适应外界胁迫中的重要作用。表达分析结果显示河北杨CBF类基因能够应答干旱、低温、高温、盐及ABA胁迫,显示了其在调控河北杨胁迫抗性中的作用。CBF transcription factor, belonging to AP2/EREBP family and specific to plant, plays an important role in plant re sponse and adaptation to abiotic stress. Previously, PhCBF4a/4b genes were characterized from Populus hopeiensis. The other six CBF-like genes, PhDREB66, PhDREB67-1, PhDREB67-2, PhDREB68, PhDREB69 and PhDREB70 were cloned. Similar to PhCBF4a/4b, the cloned genes contain all conserved domains in other CBF transcription factor, such as AP2 domain, nuclear location signals, the CBF signature sequences which bracket the AP2 domain, and the hydrophobic clusters which contribute towards the total trans-activating potential of CBF. Eight CBF genes of P. hopeiensis were assigned into three paralogous groups, two genes in one group＂ and three genes in each of the other two. The paralogs and the genes with their orthologs in P. trichocarpa show higher amino acid sequence identity. The phylogenetic analysis using known CBF homologs reveals that all Eudicot CBF genes are separately clustered from Monoeot CBF genes. The Eudicot CBF family with three clades, represented by above three paralogous groups, shows that the Populus CBF genes are duplica ted and diverged before or during speciation from the common Eudicot ancestor. Moreover, positive selection is detected in PhCBF4a with PAML, and the expression profiles show that the CBF genes of P. hopeiensis can respond to drought, cold, heat, NaC1 and ABA stress. All these reveal their important roles responsive to environmental stresses in P. hopeienis.

关 键 词：河北杨 CBF DREB 进化 胁迫 

分 类 号：S792.119[农业科学—林木遗传育种]