Simultaneous expression of abiotic stress responsive transcription factors, AtDREB2A, AtHB7 and AtABF3 improves salinity and drought tolerance in peanut (Arachis hypogaea L.).

Vittal Pruthvi,Rama Narasimhan,Karaba N Nataraja,Gerrit T.S Beemster

doi:10.1371/journal.pone.0111152

Vittal Pruthvi, Rama Narasimhan + Show 2 more

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https://doi.org/10.1371/journal.pone.0111152

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Journal: PloS one	Publication Date: Dec 4, 2014
Citations: 79	License type: CC BY 4.0

Affiliation: University of Agricultural Sciences, Bangalore

Abstract

Drought, salinity and extreme temperatures are the most common abiotic stresses, adversely affecting plant growth and productivity. Exposure of plants to stress activates stress signalling pathways that induce biochemical and physiological changes essential for stress acclimation. Stress tolerance is governed by multiple traits, and importance of a few traits in imparting tolerance has been demonstrated. Under drought, traits linked to water mining and water conservation, water use efficiency and cellular tolerance (CT) to desiccation are considered to be relevant. In this study, an attempt has been made to improve CT in drought hardy crop, peanut (Arachis hypogaea L., cv. TMV2) by co-expressing stress-responsive transcription factors (TFs), AtDREB2A, AtHB7 and AtABF3, associated with downstream gene expression. Transgenic plants simultaneously expressing these TFs showed increased tolerance to drought, salinity and oxidative stresses compared to wild type, with an increase in total plant biomass. The transgenic plants exhibited improved membrane and chlorophyll stability due to enhanced reactive oxygen species scavenging and osmotic adjustment by proline synthesis under stress. The improvement in stress tolerance in transgenic lines were associated with induced expression of various CT related genes like AhGlutaredoxin, AhAldehyde reductase, AhSerine threonine kinase like protein, AhRbx1, AhProline amino peptidase, AhHSP70, AhDIP and AhLea4. Taken together the results indicate that co-expression of stress responsive TFs can activate multiple CT pathways, and this strategy can be employed to improve abiotic stress tolerance in crop plants.

Highlights

Peanut, (Arachis hypogaea L.) an important oilseed crop, is a major source of edible oil and third most important source of vegetable protein, besides serving as a dietary source of vitamin E and phytosterols (FAO, 2010)
Acclimation to abiotic stress tolerance is governed by multiple traits among which cellular tolerance (CT) contributes significantly during all stages of growth and development
The genes that are upregulated or induced under stresses are linked to multiple tolerance pathways, and some of the candidate genes have been well characterised both in model system and crop plants [41, 42]

Summary

Introduction

Peanut, (Arachis hypogaea L.) an important oilseed crop, is a major source of edible oil and third most important source of vegetable protein, besides serving as a dietary source of vitamin E and phytosterols (FAO, 2010). To overcome a certain limitation of classical breeding approaches, genetic engineering through transgenic approach has been attempted for targeted improvement of crop towards stress tolerance [3]. There are reports on improvement of plants using transgenic approaches in different field crops such as rice [5,6,7], maize [8], soybean [9, 10] and potato [11]. Such attempts in peanut are limited [12, 13]

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