Genome-Wide Identification and Analysis of Class III Peroxidases in Betula pendula

Abstract

Background: Class III peroxidases (POD) proteins are widely present in the plant kingdom that are involved in a broad range of physiological processes including stress responses and lignin polymerization throughout the plant life cycle. However, little is known about the POD genes in Betula pendula, although it has been characterized in Arabidopsis, rice, poplar, maize and Chinese pear. The POD genes remain to be determined in Betula pendula.Results: A total of 90 nonredundant POD genes were identified in Betula pendula. (designated BpPODs). These POD genes were divided into twelve groups based on their phylogenetic relationships. The BpPODs are unevenly distributed on the 14 chromosomes. In addition, some BpPODs were located sequentially in tandem on chromosomes, inferred that tandem duplication contributes to the expansion of the POD gene family in Betula pendula. Analysis of the distribution of conserved domains of BpPOD proteins showed that all these proteins contain highly conserved motifs. We also investigated their expression patterns in different tissues, the results show that some BpPODs might play significant roles in root, xylem, leaf and flower. Furthermore, under low temperature conditions, some BpPODs showed different expression patterns at different times. Conclusions: Comprehensive study of the POD genes suggests that their functional diversity during Betula pendula growth and development. Our findings provide a basis for further functional analysis on POD gene family in Betula pendula.