Nano-biochar considers a versatile and valuable sorbent to enhance plant productivity by improving soil environment and emerged as a novel solution for environmental remediation and sustainable agriculture in modern era. In this study, roles of foliar applied nanobiochar colloidal solution (NBS) on salt stressed tomato plants were investigated. For this purpose, NBS was applied (0%, 1% 3% and 5%) on two groups of plants (control 0 mM and salt stress 60 mM). Tween-20 was used as a surfactant to prolong NBS effective stay on plant leaf surface. The results showed that 3% NBS application effectively improved the plant height, plant biomass, fruit count and fruit weight under non-stressed and stressed plants. In addition, 3% NBS application further increased the plant pigments such as chlorophyll by 72% and 53%, carotenoids by 64% and 40%, leaf relative water content by 4.1 fold and 1.07 fold under both conditions, respectively. NBS application stabilized the plasma membrane via reducing electrolyte leakage by 30% as well as reduced the lipid peroxidation rates by 46% and 29% under non-stressed and stressed plants, respectively. 3% NBS application also significantly enhanced the plants primary and secondary metabolites, as well as activities of antioxidant enzymes compared to control plants. Overall, NBS foliar application significantly improved all growth and yield indices, pigments, primary and secondary metabolites, leaf water content, antioxidant enzyme activities as well as reduced electrolyte leakage and lipid peroxidation rates in tomato to combat stress conditions. In future, studies on nano biochar interactions with soil microbiota, surface modifications, long-term environmental impacts, reduced methane gas emissions, and biocompatibility could provide insights into optimizing its use in sustainable agriculture.

Soil salinization, a prevalent form of environmental stress, leads to significant soil desertification and impacts agricultural productivity by altering the internal soil environment, slowing cellular metabolism, and modifying cellular architecture. This results in a marked reduction in both the yield and diversity of crops. Maize, which is particularly susceptible to salt stress, serves as a critical model for studying these effects, making the elucidation of its molecular responses essential for crop improvement strategies. This study focuses on the phytochrome-interacting factor 3 (PIF3), previously known for its role in freezing tolerance, to assess its function in salt stress tolerance. Utilizing two transcript variants of maize ZmPIF3 (ZmPIF3.1 and ZmPIF3.2), we engineered Arabidopsis transgenic lines to overexpress these variants and analyzed their phenotypic, physiological, biochemical, and transcriptomic responses to salt stress. Our findings reveal that these transgenic lines displayed not only enhanced salt tolerance but also improved peroxide decomposition and reduced cellular membrane damage. Transcriptome analysis indicated significant roles of hormonal and Ca2+ signaling pathways, along with key transcription factors, in mediating the enhanced salt stress response. This research underscores a novel role for ZmPIF3 in plant salt stress tolerance, offering potential avenues for breeding salt-resistant crop varieties.