Transcriptomic Changes of Drought-Tolerant and Sensitive Banana Cultivars Exposed to Drought Stress.

Muthusamy Muthusamy,Suthanthiram Backiyarani,Arumugam Chandrasekar,Subbaraya Uma,Marimuthu Somasundaram Saraswathi

doi:10.3389/fpls.2016.01609

Abstract

In banana, drought responsive gene expression profiles of drought-tolerant and sensitive genotypes remain largely unexplored. In this research, the transcriptome of drought-tolerant banana cultivar (Saba, ABB genome) and sensitive cultivar (Grand Naine, AAA genome) was monitored using mRNA-Seq under control and drought stress condition. A total of 162.36 million reads from tolerant and 126.58 million reads from sensitive libraries were produced and mapped onto the Musa acuminata genome sequence and assembled into 23,096 and 23,079 unigenes. Differential gene expression between two conditions (control and drought) showed that at least 2268 and 2963 statistically significant, functionally known, non-redundant differentially expressed genes (DEGs) from tolerant and sensitive libraries. Drought has up-regulated 991 and 1378 DEGs and down-regulated 1104 and 1585 DEGs respectively in tolerant and sensitive libraries. Among DEGs, 15.9% are coding for transcription factors (TFs) comprising 46 families and 9.5% of DEGs are constituted by protein kinases from 82 families. Most enriched DEGs are mainly involved in protein modifications, lipid metabolism, alkaloid biosynthesis, carbohydrate degradation, glycan metabolism, and biosynthesis of amino acid, cofactor, nucleotide-sugar, hormone, terpenoids and other secondary metabolites. Several, specific genotype-dependent gene expression pattern was observed for drought stress in both cultivars. A subset of 9 DEGs was confirmed using quantitative reverse transcription-PCR. These results will provide necessary information for developing drought-resilient banana plants.

Highlights

IntroductionAccording to Rabara et al (2015) drought stress affects 64% of the global land area and expected to cause significant yield loss in crop plants
Drought is one of the limiting environmental factors that affect crop production
In order to achieve a broad survey of genes associated with drought stress response of drought-tolerant and sensitive banana cultivars, total RNA was extracted from control and drought stressed leaf tissues from both cultivars

Summary

Introduction

According to Rabara et al (2015) drought stress affects 64% of the global land area and expected to cause significant yield loss in crop plants. Drought stress causes significant yield loss in bananas which. Genes Responsible for Drought Tolerance are famously known as a commercial crop of the tropical and subtropical regions of the world. As high as 65% yield loss were reported in rainfed banana production areas to drought stress (Van Asten et al, 2010). Most cultivated banana varieties are parthenocarpic and mostly triploids with AAA, AAB, and ABB genome constitution. Banana varieties with AAB or ABB genome constitution are said to be more drought tolerant and hardy due to the presence of the B genome (Davey et al, 2009; Vanhove et al, 2012). Understanding the molecular basis of how banana plants with different genomic groups respond to drought/water deficit stress is a key for developing drought tolerant banana plants

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