The power of seaweeds as plant biostimulants to boost crop production under abiotic stress

Abstract

In order to meet increasing food demands in the future, we will need to improve the current crop productivity. Abiotic stresses like drought and salinity are major factors resulting in crop yield losses and soil degradation worldwide. Recent studies suggest that seaweed-based biostimulants could be a solution for this problem. Here we summarise the current findings of using these biostimulants and highlight current knowledge gaps. Seaweed extracts were shown to enhance nutrient uptake and improve growth performance in crops under stressed and normal conditions. Seaweed extracts contain phytohormones, polysaccharides, polyphenols, lipids, amino acids and proteins. Although it has been shown that some of these compounds are active and have growth-promoting properties on plants, their underlying molecular mechanism of action and optimal applications especially in crops exposed to abiotic stress remains understudied. Seaweed extracts were shown to also improve protein content of crops and contribute to a healthy soil by facilitating water retention, soil aeration and nutrient availability, thereby promoting plant growth. In this paper we review the role of these extracts and their bioactive compounds as plant biostimulants. The targeted application to improve crop performance and the impact of seaweed extracts for enhancing the protein content of crops are discussed.