Coordinated mechanisms of leaves and roots in response to drought stress underlying full-length transcriptome profiling in Vicia sativa L

Xueyang Min,Xiaoshan Lin,Boniface Ndayambaza,Wenxian Liu,Yanrong Wang

doi:10.1186/s12870-020-02358-8

Abstract

BackgroundCommon vetch (Vicia sativa L.) is an important self-pollinating annual forage legume and is of interest for drought prone regions as a protein source to feed livestock and human consumption. However, the development and production of common vetch are negatively affected by drought stress. Plants have evolved common or distinct metabolic pathways between the aboveground and underground in response to drought stress. Little is known regarding the coordinated response of aboveground and underground tissues of common vetch to drought stress.ResultsOur results showed that a total of 30,427 full-length transcripts were identified in 12 samples, with an average length of 2278.89 bp. Global transcriptional profiles of the above 12 samples were then analysed via Illumina-Seq. A total of 3464 and 3062 differentially expressed genes (DEGs) were identified in the leaves and roots, respectively. Gene Ontology (GO) enrichment analyses identified that the dehydrin genes and Δ1-pyrroline-5-carboxylate synthase were induced for the biosynthesis of proline and water conservation. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis results indicated that the DEGs were significantly enriched in hormone signal transduction, starch and sucrose metabolism, and arginine and proline metabolism, and various drought response candidate genes were also identified. Abscisic acid (ABA; the AREB/ABF-SnRK2 pathway) regulates the activity of AMY3 and BAM1 to induce starch degradation in leaves and increase carbon export to roots, which may be associated with the drought stress responses in common vetch. Among the co-induced transcription factors (TFs), AREB/ABF, bHLH, MYB, WRKY, and AP2/ERF had divergent expression patterns and may be key in the crosstalk between leaves and roots during adaption to drought stress. In transgenic yeast, the overexpression of four TFs increased yeast tolerance to osmotic stresses.ConclusionThe multipronged approach identified in the leaves and roots broadens our understanding of the coordinated mechanisms of drought response in common vetch, and further provides targets to improve drought resistance through genetic engineering.

Highlights

Common vetch (Vicia sativa L.) is an important self-pollinating annual forage legume and is of interest for drought prone regions as a protein source to feed livestock and human consumption
Both leaf and root tissues were collected from the control and drought conditions and used for transcriptome analysis to obtain an overview of the responses of common vetch during water deprivation
We found that high concentrations of PEG caused severe inhibition of common vetch seedling growth, and moderate concentrations (20% PEG) were used for transcriptome analyses in this study (Additional file 8: Fig. S1)

Summary

Introduction

Common vetch (Vicia sativa L.) is an important self-pollinating annual forage legume and is of interest for drought prone regions as a protein source to feed livestock and human consumption. Plants frequently encounter adverse growth conditions, such as drought, salinity, and extreme temperatures These stresses can reduce plant growth and crop yield and play major roles in determining the geographic distribution of plant species [1,2,3]. Drought tolerance occurs through the production of molecules that stabilize proteins and osmotic adjustments to withstand dehydration [7, 8] These plant adaption strategies include morphological, biochemical, physiological and molecular changes underpinned by alterations in the expression of numerous genes that may include the upregulation of stress signal transduction-related genes, functional proteins and transcription factors (TFs) [9, 10]

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Conclusion