PP2 gene family in Phyllostachys edulis: identification, characterization, and expression profiles.

Background: Phloem protein 2 (PP2), a dimeric lectin, is known for its involvement in plant responses to biotic and abiotic stresses. However, research on PP2 proteins in Moso bamboo is lacking.

Results: In this study, comprehensive genome-wide analysis of the PP2-like gene family was conducted in Moso bamboo (Phyllostachys edulis), which has a significant economic and ecological value. Using HMMER3 search and InterPro domain analysis, 23 PP2-like genes (PhePP2-1 to PhePP2-23) were identified in the P. edulis genome. These genes were distributed across 12 chromosomal scaffolds, with proteins ranging from 216 to 556 amino acids in length. Phylogenetic analysis, including 163 PP2 proteins from eight plant species, revealed six distinct groups, with Group III and Group V being the largest. Gene structure and motif analyses indicated conserved domains across the PhePP2 proteins. In addition, Cis-element analysis of the promoter regions highlighted their potential regulatory roles in hormone, stress, and light responses. Expression pattern analysis using RNA-seq data showed differential expression of PhePP2 genes under drought, salt, salicylic acid, and abscisic acid treatments, indicating their involvement in stress response pathways. Furthermore, qPCR validation in different tissues and organs of Moso bamboo confirmed the expression profiles of the selected PhePP2 genes.

Conclusions: This study provides a comprehensive understanding of the functional roles of PP2-like genes in Moso bamboo and insights into their potential applications in enhancing stress tolerance and growth in plants.