Iodine priming of corn seeds induces changes in mineral profiles and bioactive compounds to obtain botanical extracts

The effects of seed priming with potassium iodide and iodate (1 and 0.5 mmol L–1) on hydroponic green forage (HGF) production from maize seeds were evaluated. The experiment followed a completely randomized design (CRD) with five treatments and four replications. Five botanical extracts (HGFs) were obtained from HGF biomass using water/ethanol (1:1 v/v). The HGF extract (HGFE) was diluted in distilled water to standardize phenolic content to 15 mg L–1 and used for lettuce seed priming in germination and vigor assays under growth chamber conditions; a foliar spray was also applied to seedlings under greenhouse conditions in a CRD. Data were analyzed using ANOVA followed by Tukey’s test (p ≤ 0.05), while non-normal data were evaluated with Kruskal-Wallis. Iodine priming increased HGF dry biomass. Mineral analysis showed no changes in macronutrients (N, P, K, Ca), but Mg decreased (55.56%). Among micronutrients, Fe increased (45.66%), while Zn (72.64%) and Mn (68.26%) decreased; Cu, B, and Mo were unchanged. KI and KIO3 (0.5 mmol L–1) produced HGFE enriched in total phenols, ascorbic acid, antioxidant capacity, and glutathione. Lettuce seed priming with these extracts improved morphological traits and antioxidant-related variables. Overall, iodine seed priming enhances forage mineral composition and generates biostimulant extracts.