Water deficit impacts plant growth and development, causing physiological disturbances that trigger oxidative stress. As an alternative, exogenous application of a sort of molecule can minimize these damages and reduce productivity losses. The iodine (I) supplementation has shown considerable benefits to stressed plants. Nevertheless, there are no results about I mitigating the water deficit stress in coffee plants. Coffee plants were grown in 10-L pots arranged wholly randomized. Four doses of potassium iodate (KIO3) were tested: 0.0, 2.5, 5.0, and 10.0 mg dm(-3) of soil, then the plants were subjected to water deficit and compared to treatments with no KIO3 and water deficit (Control). The water deficit damaged biomass and relative growth of the coffee plant. However, the application of 2.5 mg dm(-3) of KIO3 attenuated some symptoms, increasing: photosynthetic efficiency, relative water content, water deficit tolerance index, content of photosynthetic pigments, and compatible osmolytes. In addition, we observed the stimulation of the antioxidant enzymatic system, allowing higher cell membrane stability. Doses of 5.0 and 10.0 mg dm(-3) of KIO3, in spite of induced higher activation of the antioxidant system it was observed a possible toxicity effect due to excess KIO3. The application of 2.5 mg dm(-3) KIO3 via soil can modulate metabolic and biochemical processes, allowing an improvement in the growth and development of coffee plants subjected to water deficit, suggesting that it could serve as a viable strategy for managing coffee plants under drought conditions.

Kashin-Beck disease (KBD) is an endochondral osteogenesis disorder characterised by epiphysis damage and secondary deformable arthropathy induced by multiple external factors, among which selenium (Se) and iodine deficiency are important influencing factors. Iodine deficiency is usually accompanied by a low Se content in the soil in the KBD areas of China. Se can reverse oxidative damage to chondrocytes. In addition, Se is related to the bone conversion rate and bone mineral density. Low Se will hinder growth and change bone metabolism, resulting in a decrease in the bone conversion rate and bone mineral density. Thyroid hormone imbalance caused by thyroid dysfunction caused by iodine deficiency can damage bone homeostasis. Compared with Se deficiency alone, Se combined with iodine deficiency can reduce the activity of glutathione peroxidase more effectively, which increases the vulnerability of chondrocytes and other target cells to oxidative stress, resulting in chondrocyte death. Clinical studies have shown that supplementation with Se and iodine is helpful for the prevention and treatment of KBD.

Iodine deficiency is a global public health problem and dietary microgreens represent a possible cost-effective supplement. Bacillus velezensis is a commonly occurring soil bacteria that promotes plant growth. However, little attention has been paid to the effects of B. velezensis on the absorption of iodine by plants. Herein, we demonstrated that B. velezensis accelerates pepper seed germination and growth under 0.01 mmol/L KI supplement, with an 85.9% increase in fresh biomass. B. velezensis induced approximately 2.0 -fold higher iodine absorption. Likewise, colonization by B. velezensis occurred in the microgreens. Consequently, the total thiol, vitamin C, total phenolics, and the antioxidant capacity were increased. This was followed by a marked decrease in the catalase and total superoxide dismutase activities. Furthermore, the combination of B. velezensis and 0.01 mmol/L KI significantly decreased the relative water content and membrane damage (malondialdehyde and relative electrical conductivity). Intriguingly, the transcripts of ethylene biosynthesis genes CaACS10 and CaACO1 were downregulated, whereas CaACO3 expression was upregulated. Thus, the present study showed that B. velezensis accelerated iodine accumulation; improved seed germination and seedling growth; elicited antioxidant bioactivity; decreased membrane damage; and preserved vegetable microgreen quality during storage.