The use of nanoparticles has emerged as a popular amendment and promising approach to enhance plant resilience to environmental stressors, including salinity. Salinity stress is a critical issue in global agriculture, requiring strategies such as salt-tolerant crop varieties, soil amendments, and nanotechnology-based solutions to mitigate its effects. Therefore, this paper explores the role of plant-based titanium dioxide nanoparticles (nTiO2) in mitigating the effects of salinity stress on soybean phenotypic variation, water content, non-enzymatic antioxidants, malondialdehyde (MDA) and mineral contents. Both 0 and 30 ppm nTiO2 treatments were applied to the soybean plants, along with six salt concentrations (0, 25, 50, 100, 150, and 200 mM NaCl) and the combined effect of nTiO2 and salinity. Salinity decreased water content, chlorophyll and carotenoids which results in a significant decrement in the total fresh and dry weights. Treatment of control and NaCl treated plants by nTiO2 showed improvements in the vegetative growth of soybean plants by increasing its chlorophyll, water content and carbohydrates. Additionally, nTiO2 application boosted the accumulation of non-enzymatic antioxidants, contributing to reduced oxidative damage (less MDA). Notably, it also mitigated Na+ accumulation while promoting K+ and Mg++ uptake in both leaves and roots, essential for maintaining ion homeostasis and metabolic function. These results suggest that nTiO2 has the potential to improve salinity tolerance in soybean by maintaining proper ion balance and reducing MDA level, offering a promising strategy for crop management in saline-prone areas.

Antimony (Sb) is a potential threat to living organisms, but very little is known on strategies manage its toxicity in plants. This study aimed to clarify the role of Fe on alleviation Sb toxicity in a metallicolous population of Salvia spinose and its mechanisms. With regard to the toxicity of Sb in plants and the importance of Fe potential in alleviation of Sb toxicity, S. spinosa was treated with 0 and 27 mg l- 1 Sb (III or V) along with 0, 50 and 300 mu M FeEDTA in a hydroponic system. The plants exposure to iron minimized the uptake of both Sb species by Salvia roots. The limitation of H2O2 generation in response to co-application of Fe with Sb was followed by counterbalancing the antioxidant enzymes (e.g. catalase, superoxide dismutase and ascorbate peroxidase), phenols, flavonoids, lipid membrane preservation, and increase of the carbohydrates and proteins contents, which altogether improved growth in Sb-stressed plants. The Sb (III) toxicity to plants was much higher than Sb (V), but 300 mu M Fe was significantly efficient in reducing Sb damages to Salvia. Altogether, application of Fe could efficiently alleviate the physiological and morphological functions in Sb-stressed Salvia.

Plants are subject to various abiotic stresses such as water shortage and exposure to heavy metals, such as Pb in soil. These types of stress trigger a series of plant responses, ranging from a decrease in leaf gas exchange, an increase in lipid peroxidation, and even changes in the chemical composition of leaves and roots. As an essential micronutrient, Fe is involved in several physiological and biochemical processes in plants, such as photosynthetic activity, directly participating in chlorophyll synthesis and electron transport, being necessary for the maintenance of the structure and functioning of chloroplasts. The main objective of this work was to evaluate the action of Fe in mitigating Pb toxicity in young plants of the CCN 51 cacao genotype, subjected to water deficit in the soil, through photosynthetic responses and analysis of the chemical composition of different parts of the plant. Plants were grown with Pb (2 mmol Pb kg-1 soil) and different equimolar doses of Pb+Fe in the soil (2+0.5, 2+1, 2+1.5 and 2+2 mmol kg(-1) soil), maintaining constant the Pb dose, whose soil was subjected to water deficit, with gradual reduction of water content, or its moisture was maintained near to field capacity, making a total of 12 treatments, together with the control treatment (without addition of Pb and Fe in soil). It was observed that the greater Fe absorbing, by the root system, mitigated the Pb toxicity. Fe application, in adequate dose in soil (2 mmol Pb kg-1 soil + 0.5 mmol Fe kg(-1) soil), mitigated the toxic effects caused by Pb and water deficit in the plants, through the greater Fe taking up and translocation for the shoot in Pb detriment. Greater Pb translocation and accumulation in the leaves caused damage to leaf gas exchange and to the accumulation of carbohydrates in leaves. Fe and Pb applied in soil competed with each other for root absorbing regardless of soil water conditions.

Air temperatures and precipitation are predicted to increase in the future, especially at high latitudes and particularly so during winter. In contrast to air temperatures, changes in soil temperatures are more difficult to predict, as the fate of the insulating snow cover is crucial in this respect. Soil conditions can also be affected by rain-on-snow events and warm spells during winter, resulting in freeze-thaw cycles, compacted snow, ice encasement and local flooding. These adverse conditions during winter could counteract the otherwise positive effects of climate change on forest growth and productivity. For studying the effects of different winter and snow conditions on young Downy birch (Betula pubescens Ehrh.) seedlings, we carried out a laboratory experiment with birch seedlings subjected to four different winter scenarios: snow covering the seedlings (SNOW), compressed snow and ice encasement (ICE), flooded and frozen soil (FLOOD) and no snow at all (NO SNOW). After the winter treatments we simulated a spring and early summer period of 9.5 weeks, and monitored the growth by measuring shoot and root biomass of the seedlings, and starch and soluble sugar concentrations. We also assessed the stress experienced by the seedlings by measuring leaf chlorophyll fluorescence and gas exchange. Although no difference in mortality was observed between the treatments, the seedlings in the SNOW and ICE treatments had significantly higher shoot and root biomass compared with those in the FLOOD and NO SNOW treatments. We found higher starch concentrations in roots of the seedlings in the SNOW and ICE treatments, compared with those in the FLOOD and NO SNOW treatments, although photosynthesis did not differ. Our results suggest a malfunction of carbohydrate distribution in the seedlings of the FLOOD and NO SNOW treatments, probably resulting from decreased sinks. The results underline the importance of an insulating and protecting snow cover for small tree seedlings, and that future winters with changed snow pattern might affect the growth of tree seedlings and thus possibly species composition and forest productivity.