Foliar fertigation of ascorbic acid and zinc improves growth, antioxidant enzyme activity and harvest index in barley (Hordeum vulgare L.) grown under salt stress

• Published in: Plant physiology and biochemistry 2021-01, Vol.158, p.244-254
• Main Authors: Noreen, Sibgha, Sultan, Maham, Akhter, Muhammad Salim, Shah, Kausar Hussain, Ummara, Ume, Manzoor, Hamid, Ulfat, Mobina, Alyemeni, Mohammed Nasser, Ahmad, Parvaiz
• Format: Article
• Language: English
• Subjects: Antioxidants; Antioxidants - physiology; Ascorbic acid; Ascorbic Acid - administration & dosage; Barley; H2O2; Hordeum - enzymology; Hordeum - growth & development; Hydrogen Peroxide; MDA; Plant Leaves; Proline; Salinity; Salt Stress; Zinc; Zinc - administration & dosage; α-tocopherol
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2020.11.007

Crop productivity is limited by several environmental constraints. Among these, salt stress plays a key role in limiting the growth and yield production of economically important agricultural crops. However, the exogenous fertigation of vitamins and minerals could serve as a “shot-gun” approach for offsetting the deleterious effects of salts present in the rhizosphere. Therefore, an experiment was conducted to quantify the efficacy of foliar fertigation of ascorbic acid (vitamin-C) and zinc (Zn) on the physio-biochemical attributes of barley (Hordeum vulgare L. Genotype B-14011) grown in a saline environment. The salt stress resulted in a reduced biological yield associated with a decrease in chlorophyll pigment, while a significant enhancement in Na+ and Zn2+ was observed under salinity stress. Similarly, the contents of total soluble proteins, total free amino acids, lipid peroxidation, and H2O2 and the activities of antioxidative enzymes (SOD, POD, CAT, APX and proline) were significantly enhanced under salinity stress. Moreover, salinity negatively affected the yield attributes and ion uptake of plants. However, foliar fertigation with AsA +0.03% Zn enhanced vegetative growth, photosynthetic pigments, synchronized ion uptake, the synthesis of enzymatic and non-enzymatic antioxidants, and the harvest index. It is inferred from this study that among all treatments, the effect of foliar fertigation with the AsA+0.03% Zn combination not only improved the salt stress tolerance but also improved the yield attributes, which will aid in the improvement in barley seed yield and is a step to solve the problem of malnutrition through biofortification of vitamin-C and zinc. •Salinity stress resulted in reduced plant growth, biomass yield, mineral uptake and pigment content in barley.•Salinity enhanced the sodium (Na+) uptake, hydrogen peroxide (H2O2) and malondialdehyde (MDA) content in barley.•The antioxidants enhanced with salinity stress and further enhancement was observed by the application of AsA and Zn.•Supplementation of AsA and Zn regulates accumulation of H2O2 and MDA content and enhanced mineral uptake.•Combined effect of AsA and Zn was more promising in mitigating the salinity stress as compared to individual effect in barley.