Genome-wide identification and expression analysis of the VQ gene family in Cicer arietinum and Medicago truncatula.

Lei Ling,Jintao Zhu,Yue Qu,Dan Wang,Changhong Guo

doi:10.7717/peerj.8471

Abstract

Valine-glutamine (VQ) proteins are plant-specific proteins that play crucial roles in plant development as well as biotic and abiotic stress responses. VQ genes have been identified in various plants; however, there are no systematic reports in Cicer arietinum or Medicago truncatula. Herein, we identified 19 and 32 VQ genes in C. arietinum and M. truncatula, respectively. A total of these VQ genes were divided into eight groups (I–VIII) based on phylogenetic analysis. Gene structure analyses and motif patterns revealed that these VQ genes might have originated from a common ancestor. In silico analyses demonstrated that these VQ genes were expressed in different tissues. qRT-PCR analysis indicated that the VQ genes were differentially regulated during multiple abiotic stresses. This report presents the first systematic analysis of VQ genes from C. arietinum and M. truncatula and provides a solid foundation for further research of the specific functions of VQ proteins.

Highlights

Valine-glutamine (VQ) genes are plant-specific genes involved in plant growth, development, and various stress responses (Dong et al, 2018; Guo et al, 2018; Jing & Lin, 2015; Cheng et al, 2012; Li et al, 2014)
We designated the 19 VQ genes in C. arietinum as CaVQ1 to CaVQ19 and 32 VQ genes in M. truncatula as MtVQ1 to MtVQ32 according to their physical locations on the chromosomes (Table 1)
We constructed a NJ phylogenetic tree to explore the evolutionary relationship between VQ genes in C. arietinum, M. truncatula, A. thaliana and O

Summary

Introduction

Valine-glutamine (VQ) genes are plant-specific genes involved in plant growth, development, and various stress responses (Dong et al, 2018; Guo et al, 2018; Jing & Lin, 2015; Cheng et al, 2012; Li et al, 2014) They contain a conserved motif, named the VQ motif, which possesses approximately 50–60 amino acids with a highly conserved FxxhVQxhTG domain (Jing & Lin, 2015; Cai et al, 2019). VQ genes have been identified in multiple plants, such as Arabidopsis thaliana (34) (Cheng et al, 2012), Oryza sativa (39) (Kim et al, 2013a), Zea mays (61) (Song et al, 2016), Glycine max (74) (Zhou et al, 2016), and Vitis vinifera (18) (Wang et al, 2015) These genes are phylogenetically clustered into different groups, which are dependent on the analysed genomes (Jiang, Sevugan & Ramachandran, 2018). Most VQ proteins reportedly contain fewer than 300 amino acids and lack introns (Jiang, Sevugan & Ramachandran, 2018; Cai et al, 2019)

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Discussion

Conclusion