DEVELOPMENT OF A NEW TECHNOLOGY FOR PROTECTIVE BIOFORTIFICATION WITH SELENIUM OF BRASSICA CROPS

Selenium (Se) has been proved to be an essential micronutrient for animals and microorganisms. Se is considered a beneficial element for plants, determining plant growth increase and enhanced response to biotic and abiotic stress. Se biofortification of food chain is considered essential for global health, but when applied on Brassicaceae family plants is interfering with sulfur (S) metabolism, reducing the accumulation of valuable S-phytonutrients. Moreover, Se-based biostimulants were acting first as potent pro-oxidants, bleaching the treated plants. Based on accumulated knowledge regarding cross-talking between Se and S assimilation pathways, we propose the development of a new biotechnological approach for protective biofortification of Brassica crops. The aim of this study was to develop new formulations of biostimulants, based on mixtures of betaine, selenium salt and spraying adjuvant, applied on cruciferous plants, in order to obtain safe functional food with enhanced chemopreventive compounds. We treated cabbage seedlings with different variants of biostimulants, we performed plant morphometric analysis and we determined the selenium content by atomic absorption spectroscopy, the glucosinolate and sulfur aminoacid content by HPLC and we evaluated plant antitumoral activity in Caco-2 human carcinoma cell line. The results of the qualitative and quantitative chemical determinations of spectroscopy and chromatography allowed us to select the mixture of 10 mu M Na2O4Se, 10 mM betaine and 1% adjuvant, as optimal biostimulant formula that induced an equilibrated content of chemopreventive compounds in cabbage seedlings. Biological in vitro tests demonstrated that the obtained biofortified cabbage seedlings had enhanced antitumoral activity in Caco-2 human carcinoma cell line, compared to water-treated seedlings. In conclusion, we recommend a protective biofortification biotechnology based on selenium salts, betaine and spraying adjuvant to be tested in the field, on cruciferous crops of both cabbage and cauliflower.