β-Aminobutyric Acid Pretreatment Confers Salt Stress Tolerance in Brassica napus L. by Modulating Reactive Oxygen Species Metabolism and Methylglyoxal Detoxification.

Jubayer Al Mahmud,Masayuki Fujita,M Iqbal Raza Khan,Kamrun Nahar,Mirza Hasanuzzaman

doi:10.3390/plants9020241

Jubayer Al Mahmud, Masayuki Fujita + Show 3 more

Open Access

https://doi.org/10.3390/plants9020241

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Abstract

Salinity is a serious environmental hazard which limits world agricultural production by adversely affecting plant physiology and biochemistry. Hence, increased tolerance against salt stress is very important. In this study, we explored the function of β-aminobutyric acid (BABA) in enhancing salt stress tolerance in rapeseed (Brassica napus L.). After pretreatment with BABA, seedlings were exposed to NaCl (100 and 150 mM) for 2 days. Salt stress increased Na content and decreased K content in shoot and root. It disrupted the antioxidant defense system by producing reactive oxygen species (ROS; H2O2 and O2•−), methylglyoxal (MG) content and causing oxidative stress. It also reduced the growth and photosynthetic pigments of seedlings but increased proline (Pro) content. However, BABA pretreatment in salt-stressed seedlings increased ascorbate (AsA) and glutathione (GSH) contents; GSH/GSSG ratio; and the activities of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione peroxidase (GPX), superoxide dismutase (SOD), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II) as well as the growth and photosynthetic pigments of plants. In addition, compared to salt stress alone, BABA increased Pro content, reduced the H2O2, MDA and MG contents, and decreased Na content in root and increased K content in shoot and root of rapeseed seedlings. Our findings suggest that BABA plays a double role in rapeseed seedlings by reducing Na uptake and enhancing stress tolerance through upregulating the antioxidant defense and glyoxalase systems.

Highlights

Salinity is among the most detrimental stresses in plants, governing agricultural yield
Salt stress induces an initial water deficit, due to the relatively high solute concentrations in the soil, and ion-specific stresses resulting from changes in K+ /Na+ ratios [4], which lead to elevated levels of Na+ and Cl- in the plants that hamper its growth and development [5]
In order to to illustrate the impact of BABA-induced plant tolerance to salt stress, this study focused on illustrate the impact of BABA-induced plant tolerance to salt stress, this study focused on physiological physiological mechanisms to exhibit the reduction in plant sensitivity to stress upon BABA treatment

Summary

Introduction

Salinity is among the most detrimental stresses in plants, governing agricultural yield. Salt stress induces an initial water deficit, due to the relatively high solute concentrations in the soil, and ion-specific stresses resulting from changes in K+ /Na+ ratios [4], which lead to elevated levels of Na+ and Cl- in the plants that hamper its growth and development [5]. It impacts the physiological and molecular functioning of the photosynthetic components like chlorophyll, PSII and carotenoids, which are degraded, thereby decreasing the photosynthetic efficiency of the plants [4]. Reactive oxygen species (ROS) production is most prevalent during salinity stress and can damage cellular components such as protein, lipids and DNA, compromising vital cellular functions [9]

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