Uptake and partitioning of selenium in basil (Ocimum basilicum L.) plants grown in hydroponics

- Selenium supplied via nutrient solution to hydroponic basil did not affect biomass.
- Se partitioning was observed and the highest percentage accumulated in leaves.
- Se uptake rate increased during the first 27 days of treatment, then decreased.
- Selenium treatments induced a dose-dependent increase in Se uptake rate.
- Se addition to nutrient solution is an efficient tool for selenizing basil leaves.

Biofortification of edible crops with selenium (Se) may represent an alternative system for providing selenium in the human diet. The aim of the present study was to provide insights into the ability of basil plants grown in hydroponics to take up Se from the growth substrate, and to study the effects of Se concentration on plant growth and Se accumulation. The addition of sodium selenate at the rates of 4, 8 and 12 mg Se L−1 to the nutrient solution induced a dose-dependent increase in the Se uptake rate. Se was absorbed by the roots and translocated to the above-ground organs and accumulated particularly in the leaves, without affecting the biomass production of the plants. Se concentration increased during seedling growth, was highest in the younger leaves, and then declined before or upon flowering. The results clearly highlight the potential of selenizing basil shoots through the addition of selenate to the nutrient solution. This study provides crucial information for assessing the appropriate Se dosage in order to obtain the desired Se content in leaves, and the best harvest time to obtain the highest leaf Se concentration in basil. The addition of selenate to the nutrient solution could be an efficient system for providing enriched basil plants.