Selenate Differentially Alters the Content of Glucosinolates in Eruca sativa and Diplotaxis tenuifolia Grown in Soil

Selenium (Se) is a fundamental microelement for several organisms, including humans. Higher plants represent the main dietary source of Se and their enrichment in Se may infl uence sulfur (S) accumulation and consequently, the synthesis of health promoting S-containing compounds. In this study, the effect of selenate foliar fertilization on the production of total and specifi c glucosinolates (GSL) was investigated in two rocket species, Eruca sativa and Diplotaxis tenuifolia . Se accumulated in the leaves of the two plant species at a similar rate, but exerted an opposite effect on S content when supplied at high dose. Specifi cally, selenate fertilization with 10 mg Se per plant increased the leaf level of sulfur in E. sativa and reduced it in D. tenuifolia . The trend of leaf GSL accumulation in both plant species was strongly consistent with the variation in S content. We conclude that Se at high dosage affects the production of GSL in rocket plants, the increase or reduction depending on the plant species, while low doses of selenate do not signifi cantly infl uence S and GSL contents in edible tissues. Furthermore, variations in S content mediated by Se are indicative of changes in the level of GSL.