Mitigating salt stress in maize using Ecklonia maxima seaweed extracts

Abstract

Salinity stress poses a significant threat to crop productivity, making it crucial to explore strategies that alleviate its adverse effects. This study investigated the impact of Afrikelp®, a commercial seaweed extract (SE) biostimulant, derived from Ecklonia maxima on maize (Zea mays L.) plants subjected to salinity stress. Gas exchange analysis revealed that plants treated with SE Afrikelp® exhibited significantly higher photosynthetic rates under control conditions (45 % respectively) and 200 mM salt stress (95 % respectively) compared to untreated plants. Similarly, plants treated with SE Afrikelp® and 200 mM salt stress had significantly higher internal CO₂ concentrations and transpiration rates compared to untreated salt stressed plants. Morphological analysis demonstrated that SE Afrikelp® enhanced plant growth and reduced electrolyte leakage under both control and salinity stress conditions. Metabolomic profiling revealed significant alterations in primary metabolites, particularly amino acids, sugars, and organic acids. As such, the results reveal that SE Afrikelp® induced a metabolic reprogramming towards stress alleviation and enhanced defences. Overall, SE Afrikelp® demonstrated potential in mitigating the adverse effects of salinity stress on maize plants, warranting its efficacy for agricultural applications.