Algae are existing macroscopic materials with substantial benefits, including as important growth regulators and macronutrients and micronutrients for the growth of healthy crop plants. Biofertilizers obtained from algae are identified as novel production fertilizers or innovative biofertilizers without the detrimental impacts of chemicals. Seaweeds contain many water-soluble minerals and nutrients that plants can easily absorb and that are valuable for crop plants’ growth. At present, Ascophyllum nodosum (L.) Le Jolis extract outperforms chemical fertilizers in terms of increasing seed germination, plant development, and yield, as well as protecting plants from severe biotic and abiotic stresses. A. nodosum contains bioactive compounds that exhibit an array of biological activities such as antibiotic, anti-microbial, antioxidant, anti-cancer, anti-obesity, and anti-diabetic activities. A. nodosum extract (AnE) contains alginic acid and poly-uronides that improve soil’s water-carrying ability, morsel structure, aeration, and capillary action, stimulating root systems in plants, increasing microbial activity in soil, and improving mineral absorption and availability. The scientific literature has comprehensively reviewed these factors, providing information about the different functions of A. nodosum in plant growth, yield, and quality, the alleviation of biotic and abiotic stresses in plants, and their effects on the interactions of plant root systems and microbes. The application of AnE significantly improved the germination rate, increased the growth of lateral roots, enhanced water and nutrient use efficiencies, increased antioxidant activity, increased phenolic and flavonoid contents, increased chlorophyll and nutrient contents, alleviated the effects of abiotic and biotic stresses in different crop plants, and even improved the postharvest quality of different fruits.

Mung bean (Vigna radiata L.) sprout is a popular fresh vegetable, tasty and high in antioxidants. To increase yield and quality after the occurrence of both abiotic and biotic stresses, the application of seaweed extracts is of great importance. Hence, this study was conducted to determine the effect of Ascophyllum nodosum extract (ANE) in the presence of salt on the antioxidant potential of V. radiata sprouts. Different concentrations of ANE viz. 0.00, 0.01, 0.05, 0.10, and 0.50% and NaCl 0, 25, 50, 75, and 100 mM alone and in combinations were tested for researching the antioxidant potential of V. radiata sprouts at 0, 24, and 36 h of sprouting. The DPPH free-radical-scavenging activity of sprouts of V. radiata was found to increase with time and peaked at 24 h of treatment. The A. nodosum extract (0.01%) could reverse the ill effect of the low level of salinity posed by up to 25 mM NaCl. The increasing salinity deteriorated the antioxidant activity using ABTS method of sprouts down to 20.45% of the control at 100 mM NaCl. The total phenolic content (TPC), total flavonoid content (TFC), and reducing power of V. radiata sprouts was found to increase till 36 h of sprouting. A slight increase in TPC, TFC and reducing power was observed when seeds were treated with low concentrations of ANE. The elevation in TPC, TFC and reducing power upon treatment with low concentrations of ANE was also noticed in sprouts in saline combinations. Alpha amylase inhibition activity was found to reach a (67.16% ± 0.9) maximum at 24 h of sprouting at a 0.01% concentration of ANE. Tyrosinase inhibition and alpha glucosidase inhibition was 88.0% ± 2.11 and 84.92% ± 1.2 at 36 h of sprouting, respectively, at 0.01% concentration of ANE. A. nodosum extract is natural, environmentally friendly, and safe, and could be used as one of the strategies to decline stress at a low level and enhance the antioxidant activities in V. radiata sprouts, thus increasing its potential to be developed as an antioxidant-based functional food.