Genome-wide identification and expression profile analysis of CCH gene family in Populus

Zhiru Xu; Liying Gao; Mengquan Tang; Chunpu Qu; Jiahuan Huang; Qi Wang; Chuanping Yang; Guanjun Liu; Chengjun Yang

doi:10.7717/peerj.3962

Genome-wide identification and expression profile analysis of CCH gene family in Populus

PeerJ. 2017 Oct 27:5:e3962. doi: 10.7717/peerj.3962. eCollection 2017.

Authors

Zhiru Xu^{1

2}, Liying Gao¹, Mengquan Tang¹, Chunpu Qu^{2

3}, Jiahuan Huang¹, Qi Wang^{2

3}, Chuanping Yang^{2

3}, Guanjun Liu^{2

3}, Chengjun Yang³

Affiliations

¹ College of Life Science, Northeast Forestry University, HarBin, China.
² State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, HarBin, China.
³ School of Forestry, Northeast Forestry University, HarBin, China.

Abstract

Copper plays key roles in plant physiological activities. To maintain copper cellular homeostasis, copper chaperones have important functions in binding and transporting copper to target proteins. Detailed characterization and function analysis of a copper chaperone, CCH, is presently limited to Arabidopsis. This study reports the identification of 21 genes encoding putative CCH proteins in Populus trichocarpa. Besides sharing the conserved metal-binding motif MXCXXC and forming a βαββαβ secondary structure at the N-terminal, all the PtCCHs possessed the plant-exclusive extended C-terminal. Based on their gene structure, conserved motifs, and phylogenetic analysis, the PtCCHs were divided into three subgroups. Our analysis indicated that whole-genome duplication and tandem duplication events likely contributed to expansion of the CCH gene family in Populus. Tissue-specific data from PlantGenIE revealed that PtCCH genes had broad expression patterns in different tissues. Quantitative real-time RT-PCR (qRT-PCR) analysis revealed that PnCCH genes of P. simonii × P. nigra also had different tissue-specific expression traits, as well as different inducible-expression patterns in response to copper stresses (excessive and deficiency). In summary, our study of CCH genes in the Populus genome provides a comprehensive analysis of this gene family, and lays an important foundation for further investigation of their roles in copper homeostasis of poplar.

Keywords: Copper chaperone; Copper homeostasis; Copper stress; Expression profile; Populus.

Grants and funding

This study was supported by the National Natural Science Foundation of China (31470664 and 31370662), and the Fundamental Research Funds for the Central Universities (2572017EA05). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.