Genome-Wide Identification and Expression Analysis of the Plant U-Box Protein Gene Family in Phyllostachys edulis
Jie Zhou, Yaping Hu, Jiajia Li, Zhaoyan Yu, Qirong Guo
Abstract
The U-box gene encodes a ubiquitin ligase that contains a U-box domain. The plant U-box (PUB) protein plays an important role in the plant stress response; however, very few studies have investigated the role of these proteins in Moso bamboo ( Phyllostachys edulis ). Thus, more research on PUB proteins is necessary to understand the mechanisms of stress tolerance in P. edulis . In this study, we identified 121 members of the PUB family in P. edulis ( PePUB ), using bioinformatics based on the P. edulis V2 genome build. The U-box genes of P. edulis showed an uneven distribution among the chromosomes. Phylogenetic analysis of the U-box genes between P. edulis and Arabidopsis thaliana suggested that these genes can be classified into eight subgroups (Groups I–VIII) based on their structural and phylogenetic features. All U-box genes and the structure of their encoded proteins were identified in P. edulis . We further investigated the expression pattern of PePUB genes in different tissues, including the leaves, panicles, rhizomes, roots, and shoots. The qRT-PCR results showed that expression of three genes, PePUB15 , PePUB92, and PePUB120 , was upregulated at low temperatures compared to that at 25°C. The expression levels of two PePUBs , PePUB60 and PePUB120 , were upregulated under drought stress. These results suggest that the PePUB genes play an important role in resistance to low temperatures and drought in P. edulis . This research provides new insight into the function, diversity, and characterization of PUB genes in P. edulis and provides a basis for understanding their biological roles and molecular mechanisms.