Effect Of Vanadium On The Uptake And Distribution Of Organic And Inorganic Forms Of Iodine In Sweetcorn Plants During Early-Stage Development

Iodine and vanadium are elements that are closely related to organisms in water environments. Iodine and vanadium are known as "beneficial elements" that stimulate the growth and development of higher plants. Iodine is an essential element for the synthesis of the thyroid hormones triiodothyronine and thyroxine in the human body, with vanadium also known to be involved in the synthesis of thyroid hormones. The cooperation of both elements in the human body and in algae presents a question regarding the impact of vanadium interaction on iodine uptake in higher plants. The absorption of iodine from seawater in algae is known to be more efficient in the presence of vanadium, with key role in this process played by the iodoperoxidase enzyme, with vanadium acting as a cofactor. The study of the nature of the absorption of iodine by higher plants, and in particular by crops such as corn, remains insufficiently studied. The aim of this study was to investigate the effect of vanadium on iodine uptake via vanadium-dependent iodoperoxidase (vHPO) activity in sweetcorn plants (Zea mays L. subsp. Mays Saccharata Group) "Zlota Karlowa". The experiment was carried out with organic and inorganic iodine compounds, namely potassium iodide (KI), potassium iodate (KIO3), 5-iodosalicylic acid (5-ISA), and 2-iodobenzoic acid (2-IBeA), each used in a dose of 10 mu M. These compounds were applied with and without vanadium in the form of ammonium methavanadate (NH4VO3) at a dose of 0.1 mu M. A double control was used, the first without iodine and vanadium and the second with vanadium but without iodine. Root length, root mass, and above-ground weight were significantly higher after iodine and vanadium compared to controls. Plants were collected at the five true leaf stage. vHPO activity level was much higher in the roots than in the leaves, but greater variation in the leaves was observed between treatments in terms of vHPO activity. Vanadium was shown to accumulate in the roots. The use of a relatively low dose of vanadium may have caused changes in the accumulation of this element in the aerial parts of the plant, leaves, and shoots. Fertilization with iodine and vanadium compounds decreased the accumulation of most minerals, macroelements, and microelements compared to controls. The obtained results of iodine accumulation in individual parts after applying iodine and vanadium fertilization testify to the stimulating effect of vanadium on iodine uptake and accumulation.