The Effect of Bromine and Iodine on the Plant Growth, Phytochemical Composition and Antioxidant Capacity of Dandelion ( F.H. Wiggers Coll.) Plants.

Iodine is a crucial microelement for humans, and iodine deficiencies may be reduced through the consumption of iodine-enriched plants. The possible effects of exogenous bromine regarding plant growth, iodine biofortification efficiency, and the chemical composition of cultivated plants have not been previously evaluated. A two-year pot cultivation of dandelion was conducted, applying KBr and KIO in the following combinations: (1) Control, (2) 10 µM I, (3) 50 µM I, (4) 10 µM Br, (5) 50 µM Br, (6) 10 µM I + 10 µM Br, and (7) 50 µM I + 50 µM Br. An increased plant biomass indicated the low toxicity of the tested doses of I and Br for dandelion. However, a slightly increased antioxidant capacity in the leaves and roots and higher proline content in the leaves may suggest a potential stress effect of iodine and/or bromine accumulation for plants. The Br:I ratios observed in biofortified leaves and roots indicate the need to monitor bromine levels in soils or substrates used for plant cultivation in order to reduce the risk of excessive Br contents in iodine-enriched plants.