Genome-wide identification, classification, and expression of phytocyanins in Populus trichocarpa

Abstract

74 phytocyanin genes were identified in the Populus trichocarpa genome. Phylogenetic analysis grouped the PC proteins into four subfamilies (UCs, PLCs, SCs, and ENODLs). Closely related PC proteins share similar motifs, implying similar functions. Expression profiles of PtPC genes were analyzed in response to drought and salt-stress. Phytocyanins (PCs) are blue copper proteins associated with electron carrier activity that have a large influence on plant growth and resistance. The majority of PCs are chimeric arabinogalactan proteins (AGPs). In this work, we identified 74 PC genes in Populus trichocarpa and analyzed them comprehensively. Based on the ligands composition of copper-binding sites, glycosylation state, the domain structure and spectral characteristics of PC genes, PCs were divided into four subfamilies [uclacyanins (UCs), plantacyanins (PLCs), stellacyanins (SCs) and early nodulin-like proteins (ENODLs)], and phylogenetic relationship analysis classified them into seven groups. All PtPCs are randomly distributed on 17 of the 19 poplar chromosomes, and they appear to have undergone expansion via segmental duplication. Eight PtPCs do not contain introns, and each group has a similar conserved motif structure. Promoter analysis revealed cis-elements related to growth, development and stress responses, and established orthology relationships of PCs between Arabidopsis and poplar by synteny analysis. Expression profile analysis and qRT-PCR analysis showed that PtPCs were expressed widely in various tissues. Quantitative real-time RT-PCR analysis of PC genes expression in response to salt and drought stress revealed their stress-responses profiles. This work provides a theoretical basis for a further study of stress resistance mechanisms and the function of PC genes in poplar growth and development.

Genome-Wide Identification, Evolution, and Expression of GDSL-Type Esterase/Lipase Gene Family in Soybean

“…Prior studies showed that evolution of multi-gene families resulted in gene structure diversity ( Luo et al, 2018 ). The exon-intron organization of 50 and 18 GmGELP genes from subfamilies K and I are shown in Figures 6A,B , respectively.…”

VviUCC1 Nucleotide Diversity, Linkage Disequilibrium and Association with Rachis Architecture Traits in Grapevine

“…Uclacyanins are plant-specific cell-wall proteins [ 32 ] involved in fiber formation and/or tissue lignification processes [ 36 , 38 ], an activity that is intensified as a response to diverse biotic or abiotic stresses [ 33 , 37 , 39 , 40 ]. Cell wall lignification confers stiffness, stability, and strength to vascular plants, enabling the transport of water and solutes through the vascular system and affording physical barriers against environmental factors and phytopathogens [ 82 ].…”

“…Uclacyanins, stellacyanins, plantacyanins, and early nodulin-like proteins are four phytocyanins subfamilies. They are ancient blue copper proteins capable of binding to a single copper atom and function as electron transporters [ 32 , 33 ]. Genome-wide identification analyses have revealed a high variation in the number of phytocyanin genes present in different plant species.…”

“…Genome-wide identification analyses have revealed a high variation in the number of phytocyanin genes present in different plant species. To cite some examples, 38 phytocyanin genes have been identified in Arabidopsis thaliana , 46 in Solanum lycopersicum , 74 in Populus trichocarpa , and 89 in Glycine max [ 33 , 34 ]. In the grapevine genome, 41 phytocyanins have been identified [ 34 ].…”

“…Their biophysical properties and structural features indicate that phytocyanins are involved in redox reactions occurring during plant primary stress responses and in plant developmental processes including the polymerization of lignin in cell walls and the development of plant fibers [ 32 , 35 , 36 ]. In fact, multiple reports indicate that phytocyanins have a large influence on plant growth and adaptation to biotic and abiotic stresses [ 33 , 34 , 37 ]. Several uclacyanins have been shown to be specifically involved in the formation and/or deposition of lignins, as observed in the formation of pea pods [ 38 ], during the thickening of radiata pine branches reacting to gravitropism [ 39 ], or in the reinforcement of cell walls of Scots pine bark after insect attack [ 40 ].…”