Genome-wide identification, classification, and expression analysis of the phytocyanin gene family in Phalaenopsis equestris

作   者：许璐，王雪霁，王涛，李潞滨
期刊名称：Biologia Plantarum
影响因子：1.551
卷 期 号：61 (3)
页     码：1-8
关键词：arabinogalactan proteins, early nodulin-like proteins, plantacyanin-like proteins, stellacyanin-like proteins, uclacyanin-like proteins.
论文摘要：
Phytocyanins (PCs) are ancient blue copper-binding proteins in plants that bind to single type I copper atoms and function as electron transporters. PCs play an important role in plant development and stress resistance. Many PCs are considered to be chimeric arabinogalactan proteins (AGPs). Previously, 38, 62, and 84 PC genes were identified in Arabidopsis thaliana, Oryza sativa, and Brassica rapa, respectively. In this study, we identified 30 putative PC genes in the orchid Phalaenopsis equestris through comprehensive bioinformatics analysis. Based on phylogeny and motif constitution, the P. equestris phytocyanins (PePCs) were divided into five subclasses: 10 early nodulin-like proteins, 10 uclacyanin-like proteins, five stellacyanin-like proteins, four plantacyanin-like proteins, and one unknown protein. Structural and
glycosylation prediction suggested that 16 PePCs are glycosylphosphatidylinositol-anchored proteins localized to the plasma membrane, 22 PePCs contain N-glycosylation sites, and 14 are chimeric AGPs. Phylogenetic analysis indicated that each subfamily was derived from a common ancestor before the divergence of monocot and dicot lineages and that the expansion of the PC subfamilies occurred after the divergence of orchids and Arabidopsis. The number of exons in PC genes is conserved. Expression analysis in four tissues revealed that nine PC genes are highly expressed in flowers, stems, and roots, suggesting that these genes play important roles in growth and development in P. equestris. The results of this study lay the foundation for further analysis of the functions of this gene family in plants.