Maize is highly susceptible to drought, which affects growth and yield. This study investigated how bacterial volatile organic compounds (BVOCs) affect maize drought tolerance. Drought reduced shoot size but increased root length, an adaptation for accessing deeper soil moisture. BVOCs from strain D12 significantly increased root length and shoot growth under drought conditions. Drought also altered root biochemistry, decreasing enzyme activity, and increased osmolyte levels. BVOCs from strains F11 and FS4-14 further increased osmolyte levels but did not protect membranes from oxidative damage, while BVOCs from strains D12 and D7 strains reduced osmolyte levels and cell damage. In shoots, drought increased the levels of osmolytes and oxidative stress markers. BVOCs from FS4-14 had minimal effects on shoot biochemistry. BVOCs from D12 and F11 partially restored metabolic activity but did not reduce cell damage. BVOCs from D7 reduced metabolic activity and cell damage. These results suggest that BVOCs can modulate the biochemical response of maize to drought, with some strains evidencing the potential to enhance drought tolerance.

The global agricultural productivity has been significantly impaired due to the extensive use of heavy metal. Cadmium (Cd) is now recognized as a significant soil and environmental contaminant that is primarily spread by human activity. This study investigates the possible impact of melatonin (ME) in mitigating the toxicity caused by Cd in pepper (Capsicum annuum L.) seedlings. There were three groups of plants used in the experiment: control (CK) plants, Cd-stressed plants and ME-pretreated + Cd-stressed plants. The concentration of ME and Cd was 1 mu M and 0.1 mM, respectively, and applied as root application. The results described that Cd treatment remarkably reduced growth parameters, impaired pigment concentration, hindered gas exchange traits. In contrast, ME supplementation significantly recovered these parameters by increase in growth and biomass production of pepper seedlings under Cd toxicity. In addition, ME application considerably increased osmolyte production and protein level in pepper leaves and roots. Furthermore, ME positively upregulated the antioxidant enzymes activity and effectively decreased the oxidative damage in pepper leaves and roots. The enhanced antioxidant enzymes activity performed a significant role in the reduction of H2O2 and MDA concentration in plants under Cd stress. The findings indicated that the application of ME to plants effectively alleviates the stress caused by Cd exposure. Moreover, ME demonstrates significant efficacy in mitigating the adverse impacts of Cd on pepper plants.