Differential expression between drought-tolerant and drought-sensitive sugarcane under mild and moderate water stress as revealed by a comparative analysis of leaf transcriptome.

Wanapinun Nawae,Wirulda Pootakham,Chaiwat Naktang,Jeremy R Shearman,Warodom Wirojsirasak,Kittipat Ukoskit,Duangjai Sangsrakru,Peeraya Klomsa-Ard,Prapat Punpee,Klanarong Sriroth,Chutima Sonthirod,Sithichoke Tangphatsornruang,Thippawan Yoocha

doi:10.7717/peerj.9608

Wanapinun Nawae, Wirulda Pootakham + Show 11 more

Open Access

https://doi.org/10.7717/peerj.9608

Copy DOI

Abstract

Sugarcane contributes 80% of global sugar production and to bioethanol generation for the bioenergy industry. Its productivity is threatened by drought that can cause up to 60% yield loss. This study used RNA-Seq to gain a better understanding of the underlying mechanism by which drought-tolerant sugarcane copes with water stress. We compared gene expression in KPS01-12 (drought-tolerant genotype) and UT12 (drought-sensitive genotype) that have significantly different yield loss rates under drought conditions. We treated KPS01-12 and UT12 with mild and moderate water stress and found differentially expressed genes in various biological processes. KPS01-12 had higher expression of genes that were involved in water retention, antioxidant secondary metabolite biosynthesis, and oxidative and osmotic stress response than UT12. In contrast, the sensitive genotype had more down-regulated genes that were involved in photosynthesis, carbon fixation and Calvin cycle than the tolerant genotype. Our obtained expression profiles suggest that the tolerant sugarcane has a more effective genetic response than the sensitive genotype at the initiation of drought stress. The knowledge gained from this study may be applied in breeding programs to improve sugarcane production in drought conditions.

Highlights

IntroductionModern sugarcane cultivars are mainly hybrids of sugar rich Saccharum officinarum species and the wild species S. spontaneum (Shearman et al, 2016)
Sugarcane (Saccharum ssp.) is a C4 grass in the Poaceae family
The average percentage over all samples of RNA reads that could be mapped to a unique locus on the R570 sugarcane genome was 67% while the percentage of RNA reads that were mapped to multiple loci was 3% and the percentage of the unmapped reads was 26% (Table S3)

Summary

Introduction

Modern sugarcane cultivars are mainly hybrids of sugar rich Saccharum officinarum species and the wild species S. spontaneum (Shearman et al, 2016). This plant is one of the most important economic crop species of the world as it is used in both the food and energy industries. Dry conditions can have positive effects on sucrose yield of sugarcane during maturation phase (Ferreira et al, 2017). Stem and leaf growth of sugarcane is very sensitive to water stress during germination, tillering and during the vegetative growth phase (Ferreira et al, 2017). Drought can cause up to 60% yield loss in rainfed areas (Ferreira et al, 2017)

Methods

Results

Discussion

Conclusion