The bZIP gene family in watermelon: genome-wide identification and expression analysis under cold stress and root-knot nematode infection.

Youxin Yang,Jingwen Li,Hao Li,Yong Zhou,Yingui Yang,Yelan Guang

doi:10.7717/peerj.7878

Abstract

The basic leucine zipper (bZIP) family transcription factors play crucial roles in regulating plant development and stress response. In this study, we identified 62 ClabZIP genes from watermelon genome, which were unevenly distributed across the 11 chromosomes. These ClabZIP proteins could be classified into 13 groups based on the phylogenetic relationships, and members in the same group showed similar compositions of conserved motifs and gene structures. Transcriptome analysis revealed that a number of ClabZIP genes have important roles in the melatonin (MT) induction of cold tolerance. In addition, some ClabZIP genes were induced or repressed under red light (RL) or root-knot nematode infection according to the transcriptome data, and the expression patterns of several ClabZIP genes were further verified by quantitative real-time PCR, revealing their possible roles in RL induction of watermelon defense against nematode infection. Our results provide new insights into the functions of different ClabZIP genes in watermelon and their roles in response to cold stress and nematode infection.

Highlights

Plants have developed complex signaling transduction pathways to protect themselves against a variety of biotic and abiotic environmental stimuli
Watermelon Citrullus lanatus subsp. vulgaris cv. 97103 genome and protein sequences were downloaded from the cucurbit genomics database (CuGenDB; http://cucurbitgenomics.org)
The gene ontology (GO) annotation results indicated that ClabZIP proteins may participate in various biological processes (Table S5; Fig. S1)

Summary

Introduction

Plants have developed complex signaling transduction pathways to protect themselves against a variety of biotic and abiotic environmental stimuli. Various transcription factors (TFs) can bind to the cis-acting elements in the promoters of stress-responsive genes for regulating their expression to control the signaling networks of plant development and stress responses (Jin et al, 2017). The basic leucine zipper (bZIP) family is one of. The bZIP domain is composed of 60–80 amino acids in length and possesses two functionally distinct parts: a highly conserved basic region and a less conserved leucine zipper, which are linked by a hinge region (Correa et al, 2008; Dröge-Laser et al, 2018; Wang et al, 2018b). The basic region contains a characteristic motif (N-X7-R/K-X9) responsible for DNA-binding and nuclear localization, while the leucine zipper forms an amphipathic surface that mediates specific recognition and dimerization (Hu et al, 2016c; Li et al, 2016b)

Methods

Results

Discussion

Conclusion