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

Abstract

The time when plant biostimulants were considered as “snake oil” is erstwhile and the skepticism regarding their agricultural benefits has significantly faded, as solid scientific evidences of their positive effects are continuously provided. Currently plant biostimulants are considered as a full-fledged class of agri-inputs and highly attractive business opportunity for major actors of the agroindustry. As the dominant category of the biostimulant segment, seaweed extracts were key in this growing renown. They are widely known as substances with the function of mitigating abiotic stress and enhancing plant productivity. Seaweed extracts are derived from the extraction of several macroalgae species, which depending on the extraction methodology lead to the production of complex mixtures of biologically active compounds. Consequently, plant responses are often inconsistent, and precisely deciphering the involved mechanism of action remains highly intricate. Recently, scientists all over the world have been interested to exploring hidden mechanism of action of these resources through the employment of multidisciplinary and high-throughput approaches, combining plant physiology, molecular biology, agronomy, and multi-omics techniques. The aim of this review is to provide fresh insights into the concept of seaweed extract (SE), through addressing the subject in newfangled standpoints based on current scientific knowledge, and taking into consideration both academic and industrial claims in concomitance with market’s requirements. The crucial extraction process as well as the effect of such products on nutrient uptake and their role in abiotic and biotic stress tolerance are scrutinized with emphasizing the involved mechanisms at the metabolic and genetic level. Additionally, some often overlooked and indirect effects of seaweed extracts, such as their influence on plant microbiome are discussed. Finally, the plausible impact of the recently approved plant biostimulant regulation on seaweed extract industry is addressed.

Effect of Biostimulants and Storage on Discoloration Potential of Carrot

“…The application of the Kelpak demonstrated a mostly beneficial effect on the concentration of polyphenols in carrot roots after harvest ( Table 6). The use of algae biostimulants to increasing the content of polyphenols in plants is widely reported in the literature [39]. Increased biosynthesis of protective compounds such as polyphenols contributes to the increased tolerance of plants to stress [40].…”

Macroalgae—A Sustainable Source of Chemical Compounds with Biological Activities

“…In recent years, macroalgae have gained more and more interest owed to their various health promoting properties that can decrease the risks of many chronic diseases and even help to extend the lifespan [ 7 , 8 ]. Macroalgae can also be used for wastewater treatment or as a natural fertilizer in agriculture, therefore improving the quality of the products and minimizing the need for chemical fertilizers [ 9 , 10 , 11 ]. The potential of macroalgae as a source of renewable energy is also of considerable interest.…”

Physiological, Ecological, and Biochemical Implications in Tomato Plants of Two Plant Biostimulants: Arbuscular Mycorrhizal Fungi and Seaweed Extract

“…SEs also provide an alternative means to manage pests and prevent plant disease (Baloch et al, 2013), increase plant tolerance to abiotic stress (EL Boukhari et al, 2020), and improve the number of fruits or other quality traits (Hamed et al, 2018). These are a result of the combined actions of various complex pools of bioactive molecules found within SEs (Khan et al, 2009;Ertani et al, 2018).…”