Biochar (BC), a charred organic material produced through pyrolysis, has emerged as a promising and an environmentally friendly agro-strategy. This study investigated its potential to mitigate the impacts of global climate change on maize cultivation, specifically focusing on temperature stress tolerance. The research examined how the source material of biochar influences key plant stress mechanisms, including antioxidant enzymes and heat shock proteins (HSPs). To achieve this objective, the study evaluated the effects of biochar derived from three distinct sources-apple orchard pruning waste (PWBC), urban waste (UWBC), and animal manure (AMBC)-on maize plants grown under controlled conditions. A completely randomized factorial design with three replications was employed. Each biochar type was applied at a rate of 4% (w/w) to the soil. The physiological responses of maize plants were assessed under normal (25 degrees C), low (4 degrees C), and high (48 degrees C) temperature conditions. Lipid peroxidation (indicator of oxidative stress), soluble protein content, activity of antioxidant enzymes, and expression levels of HSP70 and HSP90 were analyzed. The results revealed that PWBC application, compared to without BC, significantly reduced malondialdehyde (MDA) accumulation by 38% under both low- and high-temperature stress, suggesting its potential in alleviating oxidative damage. UWBC treatment, on the other hand, demonstrated a pronounced effect on protein metabolism, with soluble protein content increasing by 16% at low and 26% at high temperature. Furthermore, biochar application under temperature stress increased antioxidant enzyme activity, thereby mitigating oxidative stress, with UWBC proving to be the most effective in stimulating antioxidant responses. The expression levels of HSP70 and HSP90 were also significantly regulated by biochar application. UWBC and AMBC treatments displayed the most pronounced effects, with HSP70 expression increasing by 4.6- and 1.6-fold, and HSP90 expression by 8.2- and 45.4-fold, respectively, particularly under high-temperature stress, compared to without BC. These findings indicate that the reduction of lipid peroxidation, activation of antioxidant defense mechanisms, and regulation of HSP70 and HSP90 transcriptional and translational in maize plants under temperature stress vary based on the source material of the biochar. Long-term studies assessing plant yield and quality are recommended to validate these findings further.

来源平台：JOURNAL OF PLANT GROWTH REGULATION