Abstract: Abscisic acid (ABA) is one of the important hormones regulating plant growth and development, and abiotic stress. As an ABA receptor, PYL is located at the top of its signaling pathway and plays a core regulatory role. However, this gene family has not been identified and analyzed in detail in loquat. In this study, 12 PYL genes were identified in loquat based on bioinformatics analysis. The molecular weight of the coding PYL protein ranged from 10.47 to 29.12 kDa, and most of them were localized in the cytoplasm. PYL family genes were distributed on 8 chromosomes. Phylogenetic tree analysis showed that PYL gene family could be divided into three subfamilies and EjPYL1 was closely related to AtPYL13. PYL proteins in loquat were consisted of motif 1-6, and motif3 was the common domain. Genes of PYL family were collinearity in species loquat. There were 2 pairs of collinearity between loquat and Arabidopsis thaliana. Cis-components in promoter of PYL genes were related to low temperature, drought, light and hormone response. RNA-seq of loquat young fruits indicated that EjPYL6 and EjPYL8 were both up-regulated by low temperature in fruit pulp and seeds. This study can provide theoretical basis for further understanding ABA signal transduction pathway and breeding new varieties of loquat with frost resistance.

Key words: Eriobotrya japonica, PYL gene family, ABA, freezing stress

摘要： 脱落酸(ABA)是调节植物生长发育与非生物胁迫的重要激素之一，ABA受体Pyrabactin Resistance 1 (PYR)-like (PYL)于信号通路的顶端发挥核心调控作用，但枇杷Eriobotrya japonica的PYL基因家族尚未鉴定。本研究通过生物信息学分析鉴定出枇杷12个PYL基因家族成员，枇杷PYL蛋白分子量为10.47～29.12 kDa，且主要定位于细胞质。枇杷PYL基因家族成员分布在8条染色体上，进化树分析显示PYL基因家族包含三个亚家族，且枇杷EjPYL1与拟南芥AtPYL13亲缘关系较近。枇杷PYL蛋白含有1～6个motif，其中motif3为家族成员共有。枇杷PYL基因家族成员在物种内存在共线性，与拟南芥的物种间共线性有2对。顺式作用元件分析发现枇杷PYL基因启动子含有低温、干旱、光以及激素响应元件。枇杷幼果转录组分析表明，果肉和种子中EjPYL6和EjPYL8基因受低温诱导上调表达。该研究结果将为枇杷ABA信号转导途径的解析和抗冻新品种培育提供理论依据。

关键词: 枇杷, PYL基因家族, ABA, 冻害胁迫