Ascophyllum nodosum-Based Biostimulants: Sustainable Applications in Agriculture for the Stimulation of Plant Growth, Stress Tolerance, and Disease Management

Abstract

Abiotic and biotic stresses limit the growth and productivity of plants. In the current global scenario, in order to meet the requirements of the ever-increasing world population, chemical pesticides and synthetic fertilizers are used to boost agricultural production. These harmful chemicals pose a serious threat to the health of humans, animals, plants, and the entire biosphere. To minimize the agricultural chemical footprint, extracts of Ascophyllum nodosum (ANE) have been explored for their ability to improve plant growth and agricultural productivity. The scientific literature reviewed in this article attempts to explain how certain bioactive compounds present in extracts aid to improve plant tolerances to abiotic and/or biotic stresses, plant growth promotion, and their effects on root/microbe interactions. These reports have highlighted the use of various seaweed extracts in improving nutrient use efficiency in treated plants. These studies include investigations of physiological, biochemical, and molecular mechanisms as evidenced using model plants. However, the various modes of action of A. nodosum extracts have not been previously reviewed. The information presented in this review depicts the multiple, beneficial effects of A. nodosum-based biostimulant extracts on plant growth and their defense responses and suggests new opportunities for further applications for marked benefits in production and quality in the agriculture and horticultural sectors.

Keywords: Ascophyllum nodosum; biostimulants; disease management; plant growth; stress tolerance.

FIGURE 1

Ascophyllum nodosum extract (ANE) improves the growth of several crops by different modes of action.

FIGURE 2

Depiction of mode of action of Ascophyllum nodosum extract (ANE) in mitigating salinity stress.

FIGURE 3

The proposed modes of action of three fractions of Ascophyllum nodosum extract (ANE): acidic, neutral, and alkaline ANE when applied to plants exposed to drought stress.

FIGURE 4

Schematic representation of proposed mode of action of Ascophyllum nodosum extract (ANE) in eliciting plant defense against different plant pathogens.