Abstract:
Selenium is an essential element for humans, therefore, adding it to plants is convenient
for biofortification. Thus, the aim of this work was to analyze experimentally the ability of
sodium selenite to increase the concentration of Se and modify the antioxidant activity in
tomato plants. We used plants of the Toro hybrid variety and applied three treatments: 0,
2 and 5 mg L-1 of selenium as sodium selenite (Na2SeO3
) using an irrigation system. Three
samplings 40, 80, and 120 days after transplantation and a quantification of the
accumulation of selenium and macronutrients in leaves, stems, and fruits were carried
out. Plant height, stem diameter, firmness, and total solids of fruits and total dry matter
were measured. The enzyme activity of catalase, glutathione peroxidase, and superoxide
dismutase was quantified. The results indicated positive effects of Se on agronomic
variables of the plants and fruit quality; however, fruit production showed no significant
differences. Se had no effect on the concentration of the macro and micronutrients. The
addition of 5 mg L-1 of Se resulted in significant increases in the concentration of selenium
on a dry basis, reaching 20.4 µg g-1 in leaves, 52.3 µg g-1 in stems, and 35.8 µg g-1 in fruits.
The increase in enzyme activity in the fruits was enhanced by the application of 5 mg L-1
of Se: There was up to 352.7% more catalase activity, 312.2% more glutathione
peroxidase activity, and 200.8% more superoxide dismutase activity compared with the
control.
Keywords: Biofortification, Catalase, Glutathione peroxidase, Sodium selenite, Superoxide
dismutase
