Genome-wide identification and expression analysis of calcium‑dependent protein kinase and its related kinase gene families in melon (Cucumis melo L.).

Haifei Zhang,Jianxiang Ma,Yanling Mo,Xiaozhen Yang,Jianqiang Yang,Yongchao Yang,Xian Zhang,Yong Zhang,Hejie Chen,Chunhua Wei,Hao Li,Ing-Feng Chang

doi:10.1371/journal.pone.0176352

Abstract

The calcium-dependent protein kinase (CDPK) is a ser/thr protein kinase that plays vital roles in plant growth, development, and responses to multiple stresses. Despite an important member of the stress responsive gene family, little is known about the evolutionary history and expression patterns of CDPK genes in melon. Herein, a total of 18 CDPK genes and 7 CDPK-related protein kinases (CRK) genes were identified in the melon genome via bioinformatic analysis, which were unevenly distributed across eleven chromosomes with an apparent exception for chromosome 3. Comparative syntenic analysis between Cucumis melo L. and Arabidopsis thaliana revealed that 13 CmCDPKs and 19 AtCPKs existed in 20 corresponding syntenic blocks. In addition, based on gene structure and phylogenetic analyses, all CmCDPKs were divided into four groups (CDPK I-IV) and CmCRKs clustered into one group (CRK I). Interestingly, group CDPK IV was clearly distinct from the other three CDPK groups, but clustered with CRK I on the phylogenetic tree, implying their origination from a common ancestor. Furthermore, CmCDPKand CmCRK genes were differentially expressed in response to various stimuli, such as biotic stress (Podosphaera xanthii), abiotic stress (salt and cold), and hormone (abscisic acid) treatment. To our knowledge, this is the first report on CDPK and CRK gene families in melon, which provides a basic foundation for functional characterizations of CmCDPK and CmCRK genes in the future.

Highlights

To survive frequently occurring environmental stresses during plant growth process, plants have evolved an effective defense mechanism comprised of sophisticated signal transduction pathways
After domain prediction of these sequences via InterProScan, SMART, Conserved Domain Database (CDD) and ScanProsite, a total of 18 CmCDPKs, and 7 CmCRKs were identified in the melon genome, designated as CmCDPK1 to CmCDPK18 and CmCRK1 to CmCRK7 based on their chromosomal positions, respectively (Table 1)
Our results revealed that all calcium-dependent protein kinase (CDPK) and CDPK-related protein kinases (CRK) genes from melon, Arabidopsis, tomato, and rice were distributed among all four groups, which is consistent with an origin of the CDPK gene before the divergence of eudicot and monocot [16,32]

Summary

Introduction

To survive frequently occurring environmental stresses during plant growth process, plants have evolved an effective defense mechanism comprised of sophisticated signal transduction pathways. Calcium (Ca2+), a universal second messenger, plays an important role in plant growth, development, and responses to various environmental stimuli [1,2,3]. During exposure of plants to stress, transient changes in Ca2+ concentrations in the cytoplasm can be sensed. CDPK and CRK gene families in melon. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Methods

Results

Discussion

Conclusion