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.

Trends in Seaweed Extract Based Biostimulants: Manufacturing Process and Beneficial Effect on Soil-Plant Systems

“…More importantly, depending on the extraction process, the yield of bioactive compounds fluctuates significantly. For instance, extract obtained through water or acid hydrolysis are reported to be rich in phytohormones [18], although such trait may also be inconsistent. Indeed, the previous findings of Ertani et al [19] revealed notable variation of indole acetic acid (IAA) and gibberellic acid (GA) content of five commercial Ascophyllum nodosum-based biostimulants produced via acid extraction, which was plausibly attributed to differences in the sampling zone, timing, and environmental conditions.…”

“…As a result, compounds with a biostimulant potential could be lost during this process [20]. Additionally, in alkali extraction, polysaccharide chains are broken down to smaller oligomers, and new compounds not initially present in the algae biomass could be formed [18], which could be advantageous or not as the specific chemical process is not fully controlled. To resolve such issues, the use of UAE could constitute a potential solution.…”

Fucoidans: Downstream Processes and Recent Applications

“…Polysaccharides, nucleic acids, and peptides are considered the main three types of bioactive polymeric macromolecules [1]. Among these, polysaccharides serve various roles in living cells including structural functions, where cellulose and chitin represent the major components of the different cell wall matrices [2,3], energy storage (e.g., starch and glycogen) [4,5], and hydration and signaling functions (e.g., mucilage and alginic acid) [6,7].…”

Combination of Ascophyllum nodosum Extract and Humic Acid Improve Early Growth and Reduces Post-Harvest Loss of Lettuce and Spinach

“…Seaweeds have been used as fertilizers and soil conditioning agents since ancient times [1,6,7]. The most widely researched seaweed as a plant biostimulant is Ascophyllum nodosum, a marine brown alga, found along the Atlantic coast of North America and Northern Europe [6,8,9]. Ascophyllum nodosum extract (ANE) contains bioactive compounds such as polysaccharides, alginates, vitamins, organic osmolytes, and hormone-stimulating substances that aid in plant growth and establishment [9][10][11].…”

“…The most widely researched seaweed as a plant biostimulant is Ascophyllum nodosum, a marine brown alga, found along the Atlantic coast of North America and Northern Europe [6,8,9]. Ascophyllum nodosum extract (ANE) contains bioactive compounds such as polysaccharides, alginates, vitamins, organic osmolytes, and hormone-stimulating substances that aid in plant growth and establishment [9][10][11]. ANE application enhances plant growth and development by increasing seed germination, root and shoot growth, and nutrient uptake [6].…”