Impact of Amino Acid Foliar Applications on Soybean under Optimal and Water-Deficit Conditions: Photosynthesis, Antioxidants, Osmotic Adjustment, and Fatty Acids

• Published in: Russian journal of plant physiology 2024-06, Vol.71 (3), p.88-88, Article 88
• Main Authors: Behroshan, Z., Zahedi, H., Alipour, A., Sharghi, Y., Zand, A.
• Format: Article
• Language: English
• Subjects: Amino acids; Antioxidants; Biomedical and Life Sciences; Carbon dioxide; chlorophyll; Conductance; Cysteine; Drought; Foliar applications; Irrigation; Leucine; Life Sciences; Lysine; Mesophyll; oils; Photosynthesis; Plant Physiology; Plant Sciences; Plant stress; Proline; Research Papers; Soybeans; Stomata; Stomatal conductance; stress tolerance; Transpiration; Valine; Water stress
• ISSN: 1021-4437; 1608-3407
• DOI: 10.1134/S1021443724604002

Amino acids aid plant stress tolerance, but their precise role in soybean drought physiology remains unclear. This study included amino acid spray treatments (cysteine, valine, leucine, commercial mix) as subplots and irrigation levels (optimal, mild, severe stress) as main plots. Under optimal irrigation, amino acid and lysine performed best for F v / F m , while cysteine performed best under severe stress. For chlorophyll content, cysteine, valine and lysine performed best with optimal irrigation, with little difference across water stress conditions. Under optimal irrigation, leucine and valine had the highest SOD levels, while leucine, valine and commercial amino acids performed best under mild stress. Cysteine and valine showed higher CAT under severe stress. Leucine had the lowest MDA without stress, while the commercial mix performed best under mild stress. Valine, amino acids and cysteine had the highest proline without stress and under mild stress, while cysteine and lysine performed best under severe stress. Minimal differences occurred without stress, while valine, amino acids and cysteine performed best under stress. In 2020, amino acids and valine had the highest photosynthesis, while cysteine performed best under severe stress. Valine had the highest mesophyll conductance, while cysteine and valine performed well in 2021. Valine had the highest CO 2 and stomatal conductance without stress. All treatments showed superior transpiration. Without stress in 2020, cysteine, valine and amino acids had the highest oil yield, while leucine had it in 2021. Modulation of osmolytes like proline and antioxidants such as SOD and CAT helped valine and cysteine protect soybean plants against water stress.