Amelioration of cadmium toxicity in Vicia faba via modulation of caffeic acid O-methyltransferase gene expression by biochar and nanobiochar

Nanobiochar-assisted phytostabilization of lead and cadmium in mustard (Brassica campestris L.) is associated with reduced metal availability and improved physiological performance.

Nanobiochar is well documented for heavy metal removal from water, but its efficacy in soil phytostabilization remains less explored. This study compared nanobiochar (NB) and rice husk powder (RH) at 50 and 100 g kg-1 for improving Pb and Cd phytostabilization in mustard (Brassica campestris L.) under pot conditions. Compared with the no-adsorbent treatment, NB at 100 g kg-1 increased shoot fresh weight by 73.2% under Pb stress and 2.02-fold under Cd stress. It also increased pod number by 46.8% under Pb and 52.5% under Cd stress, while total seeds per plant increased by 80.1% and 2.26-fold, respectively. NB enhanced chlorophyll a, total chlorophyll, carotenoids, soluble sugars, and shoot accumulation of N, P, S, Ca, and K. Importantly, NB at 100 g kg-1 increased total Pb and Cd retention in soil by 12.5% and 6.6%, respectively, while reducing available Pb and Cd by 90.3% and 81.8%, respectively. It also reduced Pb and Cd accumulation in roots and shoots and decreased BAF values for both metals. Pb TF declined, whereas Cd TF showed a metal-specific response. Overall, NB-assisted phytostabilization was associated with reduced metal availability, lower plant metal accumulation, improved nutrient acquisition, and better physiological performance.

Exogenous sodium nitroprusside alleviates cadmium toxicity in Solanum nigrum via antioxidant activation, metal redistribution, and gene expression modulation.

Dose-Dependent Effects and Metabolomic Analysis of Foliar-Applied Carbon Dots on Cotton (Gossypium hirsutum L.) Growth

While carbon dots (CDs) are promising green nanomaterials for sustainable agriculture, how they regulate cotton growth via physiological and metabolic reprogramming remains poorly understood. This study evaluated foliar CD application (0–200 mg·L−1) to uncover dose–response patterns and metabolic drivers. CDs exerted a concentration-dependent impact, with 100 mg·L−1 yielding optimal results. This application markedly boosted shoot and root biomass (fresh weight: 103.43% and 44.28%; dry weight: 56.03% and 40.39%) and enhanced specific leaf area by 52.51% over the control. CDs improved photosynthetic efficiency (elevated Pn, Gs, and E values, alongside increased chlorophyll a and carotenoids) and strengthened antioxidant defenses (enhanced leaf POD/SOD and root POD/CAT activities). Despite mild MDA increases indicating oxidative stress, accumulated proline and soluble sugars in roots suggested adaptive osmotic adjustment. These findings suggest that CDs maintain physiological homeostasis by modulating antioxidant defense and osmotic adjustment. Untargeted metabolomics identified 2440 metabolites. Phenylpropanoid biosynthesis and flavonoid biosynthesis were the most prominently enriched pathways based on KEGG enrichment results. K-means and correlation analyses revealed key metabolites linked to cotton biomass. Overall, CDs facilitate cotton development through synergistic physiological and metabolic reprogramming, underscoring their potential as innovative agricultural growth regulators.

Salicylic acid enhanced the chromium tolerance in pea (Pisum sativum) by mitigating the oxidative damage and gene expression

Phytotoxic effects of olive mill waste on primary metabolism and morpho-physiological parameters of broad bean (Vicia faba L.)

A mechanistic framework for understanding how pulse crops reprogram their primary metabolism to survive high-phenolic organic waste exposure is provided, highlighting the dual nature of OMW as both a phytotoxin and a potential metabolic stimulus.

Differential modulation of growth markers and nutrient limitation signaling molecules mediated by zinc oxide nanoparticles in black nightshade (Solanum nigrum L.)

A pot experiment was conducted to evaluate the effects of zinc oxide nanoparticles (ZnONPs) and bean husk extract (BHE) on black nightshade. Functional groups, morphological characteristics, and elemental compositions of ZnONPs and BHE were characterized. Growth parameters, reactive oxygen species (ROS), and antioxidant activities were also assessed in the plants. The study followed a randomized complete block design with five replications (n = 5). Both ZnONPs and BHE contained alcohol, hydroxyl, silicon-containing, and aliphatic nitro groups. Internal alkyne, imino, and azo groups were identified in ZnONPs, whereas terminal alkyne and isothiocyanate groups were specific to BHE. Zinc (70.56 wt%; 50.45 at%) and silica (50.25 wt%; 20.34 at%) were the dominant elements in ZnONPs and BHE, respectively. Average particle sizes were 5.64 nm for ZnONPs and 9.19 nm for BHE. ZnONPs at 1.0% significantly (p < 0.05) enhanced plant height (62.33 cm) and leaf number (64.67). Malondialdehyde and hydrogen peroxide levels were higher in control plants but decreased with increasing ZnONP concentrations. In conclusion, ZnONPs, particularly at 1.0%, improved growth and reduced oxidative stress markers, indicating their potential as sustainable soil amendments in crop production systems.