Open Access

ARTICLE

Exogenous Selenium Mitigates Salt Stress in Soybean by Improving Growth, Physiology, Glutathione Homeostasis and Antioxidant Defense

Hesham F. Alharby¹, Mirza Hasanuzzaman^2,*, Hassan S. Al-Zahrani¹, Khalid Rehman Hakeem¹
1 Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
2 Department of Agronomy, Sher-e-Bangla Agricultural University, Dhaka, 1207, Bangladesh
* Corresponding Author: Mirza Hasanuzzaman. Email:
(This article belongs to this Special Issue: Plant Physiology for Crop Production and Sustainable Agriculture)

Phyton-International Journal of Experimental Botany 2021, 90(2), 373-388. https://doi.org/10.32604/phyton.2021.013657

Received 15 August 2020; Accepted 16 October 2020; Issue published 07 February 2021

Abstract

The mechanism of selenium (Se)-induced salt tolerance was studied in moderately sensitive soybean (Glycine max L.) plants. To execute this view, soybean plants were imposed with salt stress (EC 6 dS m⁻¹ ) applying NaCl. In other treatments, Se (0, 25, 50 and 75 µM Na₂SeO₄) was sprayed as co-application with that level of salt stress. Plant height, stem diameter, leaf area, SPAD value decreased noticeably under salt stress. Altered proline (Pro) level, together with decreased leaf relative water content (RWC) was observed in salt-affected plants. Salt stress resulted in brutal oxidative damage and increased the content of H₂O₂, MDA level and electrolyte leakage. Exogenous Se spray alleviated oxidative damage through boosting up the antioxidant defense system by increasing the activity of antioxidant enzymes such as catalase (CAT), peroxidase (POD) and glutathione reductase (GR), as well as by improving non-enzymatic antioxidants like glutathione (GSH) and GSH/glutathione disulfide (GSSG). The upregulated antioxidant defense system, restored Pro and leaf RWC, higher SPAD value conferred better growth and development in Se-sprayed salt-affected soybean plants which altogether put forth for the progressive yield contributing parameters and finally, seed yield. Among different doses of Se, soybean plants sprayed with 50 µM Na₂SeO₄ showed better salt tolerance.

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Keywords

Trace elements; selenium; antioxidant system; oxidative stress; salinity; oilseed crop

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