谷子PYR/PYL/RCAR基因家族进化及表达分析

Evolution and Expression Analysis of the PYR/PYL/RCAR Gene Family in Setaria italica

脱落酸(abscisic acid,ABA)是植物五大激素之一,在植物的生长发育及逆境胁迫中发挥重要的作用。PYR/PYL/RCAR(pyrabactin resistance/pyr1-like/regulatory components of ABA receptor)为ABA的受体蛋白,是ABA信号传导网络中的核心组分。谷子为重要的旱作模式植物,为了解谷子PYL基因家族的进化情况,本研究采用生物信息学手段,在全基因组范围水平对谷子PYL基因家族进行了分析。利用同源比对的方法,鉴定到9个PYL基因,被分成三大类。谷子与拟南芥、水稻、高粱和玉米PYL基因的系统进化树显示,PYL基因家族在单双子叶植物分歧之后,进行了各自演化,但是在禾本科植物中,该基因家族相对更保守一些,Ks和同源性分析表明谷子的PYL基因大多数在谷子与水稻物种分歧之前就已经存在。谷子9个PYL基因分布于5条染色体上,PYL蛋白多定位于细胞质,大多为酸性亲水性蛋白,组织表达分析显示谷子PYL基因的表达具有明显的组织特异性;启动子分析结果显示,谷子只有两个PYL基因含有抗旱相关元件MBS,且每个基因只包含一个元件。这些结果将会为进一步研究谷子PYL基因的功能及作用机制提供一定的帮助。

Abscisic acid(ABA)is one of the five major hormones in plants and plays important roles in plant growth,development and stress.PYR/PYL/RCAR(pyrabactin resistance/pyr1-like/regulatory components of ABA receptor)is the receptor protein of ABA and a core component of the ABA signaling network.Setaria italica is an important dry farming model plant.In order to understand the evolution of the PYL gene family in Setaria italica,we studied the PYL gene family in the whole genome-wide by using the bioinformatic methods.9 PYL genes were identified by means of program of homologous alignment,and they were divided into three groups.The phylogenetic tree of the PYL genes in Setaria italica,Arabidopsis thaliana,Oryza sativa,Sorghum bicolor and Zea mays showed PYL gene families evolved independently after the divergence of monodicotyledons.However,in gramineous plants,this gene family was relatively more conservative.Ks and homology analysis indicated that most PYL genes of Setaria italica existed before the divergence between millet and rice species.The nine PYL genes of Setaria italica distributed on five chromosomes.Most of the PYL proteins localized in cytoplasm,acidic and hydrophilic. The tissue expression analysis showed that Setaria italica PYL genes had significant tissue expressionspecificity. The results of the promoter analysis showed that only two Setaria italica PYL genes contained droughtresistant related elements, and each gene contains only one element. These results will provide help for furtherstudy of the function and mechanism of the PYL gene in Setaria italica.