海岛棉5个CBF/DREB基因的克隆与表达分析

Characterization and Expression Analysis of Five CBF/DREB Genes from Gossypium barbadense L.

低温、干旱和盐渍是影响作物生长、产量和全球地理分布的重要非生物胁迫。CBF/DREB转录因子是参与植物非生物胁迫应答反应的重要调控蛋白。为了更好地了解棉花CBF家族基因,通过生物信息学的方法,从海岛棉中克隆了5个具有完整开放阅读框的CBF基因,命名为Gb CBF1―Gb CBF5。这5个基因编码的蛋白与其他植物冷胁迫相关的CBF蛋白具有高度的保守性,含有1个AP2功能结构域和2个特征基序。系统进化树分析表明,这5个基因与拟南芥的3个参与冷胁迫的CBF基因一起聚类在DREB亚家族中的A-1亚组。通过RT-PCR的方法分析了海岛棉基因Gb CBF1―5在高盐(200 mmol·L-1 Na Cl)、干旱、4℃低温等非生物胁迫处理下的表达模式。结果表明其中2个基因在冷胁迫下上调表达,5个基因在干旱和盐处理下均下调表达。这些为进一步探索CBF基因在棉花逆境胁迫应激反应中的作用提供了有价值的信息。

Low temperature, drought, and salinity are major abiotic stresses that influence the survival, productivity, and geo- graphical distribution of many important crops worldwide. The C-repeat/dehydration-responsive element binding transcription faetors（CBF/DREB） are important proteins involved in the response to plant abiotic stresses. To better understand CBF genes, we identified five CBFs from island cotton（Gossypium barbadense L.） using abioinformatics approach. These genes （GbCBF1- GbCBF5） were shown to encode proteins that share a high similarity with plant cold stress-related CBF proteins, which contain the classic AP2 domain and two CBF signature sequences. Phylogenetic analysis revealed that the isolated cotton CBF genes could be classified into the A-1 subgroup of the DREB subfamily with CBF1-3 genes in Arabidopsi＆ Semi-quantitative reverse transcription PCR was used for the expression profiling of the five GbCBF genes under different abiotic stresses （200 mmol. L NaCl, drought, and 4℃）. Two of the GbCBF genes were shown to be up-regulated in cotton plants under cold stress, while all the five genes were down-regulated under salinity and drought treatments. Our findings provide valuable information for further exploring the roles of the CBFgenes in cotton development and in the response to stress.