Overexpression of HVA1 Enhances Drought and Heat Stress Tolerance in Triticum aestivum Doubled Haploid Plants.

Harsha Samtani,Aishwarye Sharma,Paramjit Khurana

doi:10.3390/cells11050912

Abstract

Plant responses to multiple environmental stresses include various signaling pathways that allow plant acclimation and survival. Amongst different stresses, drought and heat stress severely affect growth and productivity of wheat. HVA1, a member of the group 3 LEA protein, has been well known to provide protection against drought stress. However, its mechanism of action and its role in other stresses such as heat remain unexplored. In this study, doubled haploid (DH) wheat plants overexpressing the HVA1 gene were analyzed and found to be both drought-and heat stress-tolerant. The transcriptome analysis revealed the upregulation of transcription factors such as DREB and HsfA6 under drought and heat stress, respectively, which contribute toward the tolerance mechanism. Particularly under heat stress conditions, the transgenic plants had a lower oxidative load and showed enhanced yield. The overexpression lines were found to be ABA-sensitive, therefore suggesting the role of HsfA6 in providing heat tolerance via the ABA-mediated pathway. Thus, apart from its known involvement in drought stress, this study highlights the potential role of HVA1 in the heat stress signaling pathway. This can further facilitate the engineering of multiple stress tolerance in crop plants, such as wheat.

Highlights

Different abiotic stresses such as drought, salinity, cold, and heat are the major factors that affect plant growth and development
In order to understand the molecular evolution of the Hordeum vulgare aleurone 1 (HVA1) gene, a phylogenetic tree was constructed of LEA3 protein sequences from different plant species such as Triticum aestivum, Zea mays, Oryza sativa, Arabidopsis thaliana, and Solanum tuberosum (Figure 1A)
15 members of LEA3 were identified in wheat, HVA1 was observed to group with three members of TaLEA3, i.e., (TaLEA3-13, TaLEA3-14, and TaLEA3-15)

Summary

Introduction

Different abiotic stresses such as drought, salinity, cold, and heat are the major factors that affect plant growth and development. In response to these stresses, plants have evolved defense mechanisms that consist of proteins that directly or indirectly aid in abiotic stress tolerance. The isolation of the first LEA protein was achieved from cotyledons of cotton and, as it accumulated in the late embryonic stage, it was named as LEA [3]. Thereafter, LEAs have been found to express during the late stage of seed maturation and in various vegetative organs such as root, stem, leaves, and other tissues throughout the plant development [4,5]. LEA proteins have been reported in different organisms such as Cyanobacteria, Arabidopsis thaliana, Oryza sativa, and Triticum aestivum and in prokaryotes such as Rotifers, which highlights their wide distribution [1,6]

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Results

Conclusion