Identification and Characterization of the Gene Family and Its Expression Pattern under Phytohormone Treatment and Abiotic Stress in

Ascorbate peroxidase (APX) is a member of class I of the heme-containing peroxidase family. The enzyme plays important roles in scavenging reactive oxygen species for protection against oxidative damage and maintaining normal plant growth and development, as well as in biotic stress responses. In this study, we identified 11 genes in the genome using bioinformatic methods. Phylogenetic analysis revealed that the PtrAPX proteins were classifiable into three clades and the members of each clade shared similar gene structures and motifs. The genes were distributed on six chromosomes and four segmental-duplicated gene pairs were identified. Promoter -elements analysis showed that the majority of genes contained a variety of phytohormone- and abiotic stress-related -elements. Tissue-specific expression profiles indicated that the genes primarily function in roots and leaves. Real-time quantitative PCR (RT-qPCR) analysis indicated that transcription was induced in response to drought, salinity, high ammonium concentration, and exogenous abscisic acid treatment. These results provide important information on the phylogenetic relationships and functions of the gene family in .