Marine macroalga as source of bioactive compounds for horticultural crops

SALCEDO, M.F.; PEREZ, M; DELLATORRE, F.G.; CASALONGUÉ, C.A.; MANSILLA, A.Y.

Mendoza

Congreso; LVIII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research; 2022

Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular

The rising population and global demand for food have led traditional agriculture to excessive use of agrochemicals for increasing crop productivity. This intensive agricultural production has eventually resulted in a seriously negative impact on the environment and human health. In this sense, seaweed extracts are currently regarded as an important plant biostimulants category with beneficial effects to improve crop health and stress resilience. Undaria pinnatifida is an abundant but also, invasive macroalgae in Argentinean coast. The aim of this work was to analyze the effectiveness of ethanolic algae extracts as sources of bioactive compounds in two horticulture plant species, tomato and lettuce. For this purpose, differential extractions with 75% (v/v) ethanol from total biomass (ET) and sporophylls (ES) were carried out and polyphenols, soluble proteins, free proline and antioxidant activity were quantified. The mean concentration of total phenolic compounds (expressed as mg of gallic acid equivalent in 100 g of dry weight) was higher in the ES (96,3) than in ET (68,9). Similarly, ES has 25% more antioxidant activity than ET. Regarding soluble protein and free proline content, no differences were found between both extracts. Then, we examined the dose-dependent effects of ES (0.001%, 0.01%, and 0.1% v/v) on tomato (Solanum Lycopersicum) seed germination. Treatment of seeds with 0.001% (v/v) ES promoteda statistically significant increase of 20% on germination efficiency and fresh biomass in 10-day-oldseedlings compared with control. In order to evaluate the effect of ES on plants grown under stressenvironmental condition, lettuce (Lactuca sativa) seedlings were subjected to nutritional stress. For that, seedlings were cultivated hydroponically in nutrient-deficient media (0.25x ATS), supplemented or not with ES (0.01%, and 0.1% v/v). Lettuce plants treated with 0.01% (v/v) ES showed an increase of approximately 160% and 170% in fresh and dry biomass, respectively. ES-supplemented plants also showed an increase of around 200% in total chlorophyll content with respect to control. Therefore, our evidence indicates the high technological potential of macroalgal biomass and allows us to deep into the bioprospection study as a source of bioactive compounds with productive beneficial in plants.