Abstract
<jats:p>The deficiency of essential micronutrients, particularly iodine, poses a serious threat to public health. In this regard, the search for effective methods of biofortification of plant materials, including the use of plant growth-promoting (PGP) rhizobacteria, is a relevant task. The aim of this study was to evaluate the PGP-activity of three Pseudomonas sp. strains (CTF2, CTF7, STF13), as well as their effect on growth parameters, photosynthetic pigment content, and iodine accumulation in Vigna radiata (L.) R. Wilczek (mung bean) microgreens in combination with foliar treatment with potassium iodide and potassium iodate solutions. The strains were isolated from the rhizosphere of Tussilago farfara growing in technogenically disturbed areas. A vegetation experiment was conducted using a hydroponic system with seed inoculation followed by iodine treatment of the plants. It was found that strain STF13 exhibited the highest ability to synthesize indole-3-acetic acid and the highest 1-aminocyclopropane-1-carboxylate deaminase activity. Inoculation of seeds with this strain led to the greatest increases in fresh and dry biomass of 14-day-old seedlings, as well as in their growth vigor index. All studied strains increased the content of chlorophylls and carotenoids by an average of 19% compared to the control. Foliar treatment with iodine significantly increased the content of photosynthetic pigments (by 23% on average) and promoted the accumulation of iodine in microgreens: when using KI, the content of the element increased by 14.3 times, KIO₃ – by 8.8 times. Thus, the combination of inoculating V. radiata seeds with promising Pseudomonas sp. strains (especially STF13 and CTF2) together with foliar iodine application increases the biological value of microgreens, confirming the effectiveness of this approach.</jats:p>