Genome-Wide Gene Expression Profiles Analysis Reveal Novel Insights into Drought Stress in Foxtail Millet (Setaria italica L.).

Ling Qin,Yanbing Yang,Xiao Yu,Erying Chen,Feifei Li,Zhenyu Liu,Ying Ruan,Yan’An Guan,Bin Liu,Runfeng Wang,Hailian Wang,Huawen Zhang

doi:10.3390/ijms21228520

Abstract

Foxtail millet (Setaria italica (L.) P. Beauv) is an important food and forage crop because of its health benefits and adaptation to drought stress; however, reports of transcriptomic analysis of genes responding to re-watering after drought stress in foxtail millet are rare. The present study evaluated physiological parameters, such as proline content, p5cs enzyme activity, anti-oxidation enzyme activities, and investigated gene expression patterns using RNA sequencing of the drought-tolerant foxtail millet variety (Jigu 16) treated with drought stress and rehydration. The results indicated that drought stress-responsive genes were related to many multiple metabolic processes, such as photosynthesis, signal transduction, phenylpropanoid biosynthesis, starch and sucrose metabolism, and osmotic adjustment. Furthermore, the Δ1-pyrroline-5-carboxylate synthetase genes, SiP5CS1 and SiP5CS2, were remarkably upregulated in foxtail millet under drought stress conditions. Foxtail millet can also recover well on rehydration after drought stress through gene regulation. Our data demonstrate that recovery on rehydration primarily involves proline metabolism, sugar metabolism, hormone signal transduction, water transport, and detoxification, plus reversal of the expression direction of most drought-responsive genes. Our results provided a detailed description of the comparative transcriptome response of foxtail millet variety Jigu 16 under drought and rehydration environments. Furthermore, we identify SiP5CS2 as an important gene likely involved in the drought tolerance of foxtail millet.

Highlights

Plants often encounter adversity stresses including drought, extreme temperatures, salinity, soil nutrient deficiency, increased light intensity, and ionic toxicity [1]
In the present study, we evaluate physiological parameters and investigate gene expression patterns using RNA sIenqt.uJ.eMnocli.nSgci.o2f02t0h, 2e1,d8r5o20ught-tolerant foxtail millet variety (Jigu 16) treated with drought stress3aonf d21 rehydration
Aenmtoanngd tthhoossee ggeenneess, wSiePr5eCcSh2oissenanfoimr fpuortrhtaenrtagneanlyesliisk.ely involved in the drought tolerance of foxtail millet. 22..1.RPehseunlotstypic and Physiological Analyses of Foxtail Millet under Drought Stress and Rehydration

Summary

Introduction

Plants often encounter adversity stresses including drought, extreme temperatures, salinity, soil nutrient deficiency, increased light intensity, and ionic toxicity [1]. Among these abiotic stresses, drought is the most serious for plants, resulting in stunted growth and yield reduction. Plants adapt to drought stress through a series of changes in molecular, cellular, and physiological processes that can aid survival. Many plants raise their cellular penetration potential by accumulating proline, in order to maintain a stable intracellular environment under stress [2]. A small genome (515 Mb), less repetitive DNA, self-pollination, and a short life cycle make foxtail millet an ideal model system for research into stress tolerance [4,5,6,7]

Methods

Results

Conclusion