Genome-Wide Identification and Expression Analysis of the CaNAC Family Members in Chickpea during Development, Dehydration and ABA Treatments

Chien Van Ha,Keiichi Mochida,Saad Sulieman,Lam-Son Phan Tran,Dong Van Nguyen,Uyen Thi Tran,Maryam Nasr Esfahani,Yasuko Watanabe,Ji-Hong Liu

doi:10.1371/journal.pone.0114107

Abstract

The plant-specific NAC transcription factors (TFs) play important roles in regulation of diverse biological processes, including development, growth, cell division and responses to environmental stimuli. In this study, we identified the members of the NAC TF family of chickpea (Cicer arietinum) and assess their expression profiles during plant development and under dehydration and abscisic acid (ABA) treatments in a systematic manner. Seventy-one CaNAC genes were detected from the chickpea genome, including 8 membrane-bound members of which many might be involved in dehydration responses as judged from published literature. Phylogenetic analysis of the chickpea and well-known stress-related Arabidopsis and rice NACs enabled us to predict several putative stress-related CaNACs. By exploring available transcriptome data, we provided a comprehensive expression atlas of CaNACs in various tissues at different developmental stages. With the highest interest in dehydration responses, we examined the expression of the predicted stress-related and membrane-bound CaNACs in roots and leaves of chickpea seedlings, subjected to well-watered (control), dehydration and ABA treatments, using real-time quantitative PCR (RT-qPCR). Nine-teen of the 23 CaNACs examined were found to be dehydration-responsive in chickpea roots and/or leaves in either ABA-dependent or -independent pathway. Our results have provided a solid foundation for selection of promising tissue-specific and/or dehydration-responsive CaNAC candidates for detailed in planta functional analyses, leading to development of transgenic chickpea varieties with improved productivity under drought.

Highlights

Chickpea (Cicer arietinum L.) is one of the major legume crops cultivated throughout the world, especially in the Afro-Asian countries, providing great supplies of protein, carbohydrate, mineral, vitamin, and health-promoting fatty acid-rich food for human consumption [1]
Our results have provided an insight into the regulatory functions of the CaNACs in chickpea, and laid a foundation for in-depth in planta functional characterization of selected CaNAC genes with the final aim to use them for the improvement of drought tolerance in chickpea by genetic engineering
To identify all the CaNAC genes annotated in the chickpea genome, we first collected all the predicted CaNAC genes from PlantTFDB and iTAK

Summary

Introduction

Chickpea (Cicer arietinum L.) is one of the major legume crops cultivated throughout the world, especially in the Afro-Asian countries, providing great supplies of protein-, carbohydrate-, mineral-, vitamin-, and health-promoting fatty acid-rich food for human consumption [1]. Chickpea productivity is severely affected by drought which has made development of drought-tolerant chickpea cultivars is the most important goal in many chickpea research programs [5,6,7]. To cope with drought stress, intensive research has been conducted in recent years in both model and crop plants to discover and elucidate genes and molecular mechanisms that regulate drought responses [8,9,10,11]. Within the regulatory networks that control the signal transduction from stress signal perception to stress-responsive gene expression, various transcription factors (TFs) and their DNA binding sites, the so-called cis-acting elements, act as molecular switches for stress-responsive gene expression, enabling plants adapt better to the adverse stressor [12, 13]. Discovery and genetic engineering of genes encoding novel TFs have the potential to develop transgenic crop plants with superior yield under stress conditions

Methods

Results

Conclusion