紫色酸性磷酸酶（purple acid phosphatase, PAP）是一类金属磷酸酯酶,参与植物的磷素利用、碳代谢、细胞壁合成等多种生理功能，尤其是对磷缺乏的适应。本研究利用生物信息学手段在花生（Arachis hypogaea L.）全基因组水平上对PAP基因家族进行了鉴定，并对其系统进化关系、保守结构域、基因结构以及它们在22个组织中的表达模式进行了分析。结果表明：花生基因组中有39个AhPAP基因，氨基酸序列长度为205~905，等电点大多数都小于7，蛋白质C端均含有金属磷酸酶结构域。以花生、拟南芥、水稻、苜蓿共74个PAP蛋白构建的系统发育树可分为四组，每组中都含有来自不同物种的PAP，并没有因为物种差异而各自聚为一类。AhPAP基因家族中部分成员的表达具有组织特异性，arahy.P03NME、arahy.DAPS6C在根瘤中表达量最高，而它们在其他组织中表达量较低或未检测到表达。本研究为揭示AhPAP基因家族在花生中的生物学功能奠定了基础。

Purple acid phosphatases (PAPs) are the members of metallo-phosphoesterase family genes, which involve in multiple physiological functions, such as phosphorus utilization, carbon metabolism, and cell wall synthesis, especially adapt to phosphorus deficiency. In this study, we used bioinformatics method to identify the PAP gene family in peanut plant (Arachis hypogaea L.) at genome-wide level, analyzed their phylogenetic relationship, conserved domain, gene structure, and expression pattern in 22 tissues. Results showed that a total of 39 AhPAP genes were characterized in peanut genome, their amino acid sequence length ranged from 205 to 905, the isoelectric points of majority PAP proteins were less than 7, as well the metallophosphatase domain existed in the C-terminal of PAP protein sequences. Phylogenetic tree was constructed with 74 PAPs that obtained from peanut, Arabidopsis, rice and medicago genome, and the entire PAPs could be divided into 4 subgroups. Each subgroup contained PAPs from different plant species, and they were not clustered into one category due to the species difference. Furthermore, the expression of several AhPAPs presented tissue-specific, arahy.P03NME and arahy.DAPS6C exhibited the highest expression levels in nodule, but lower or not detected in other tissues. Totally, our results laid a foundation for next revealing the biological function of AhPAPs in peanut.