Excessive accumulation of cadmium (Cd) impairs crop growth by inducing oxidative damage through the generation of reactive oxygen species (ROS). In this study, a biocompatible ferruginated carbon quantum dots (Fe-CQDs) nanozyme is developed to target ROS, thereby reducing oxidative damage and improving the absorption and transfer of Cd ions in wheat. Notably, Fe-CQDs exhibit multi-enzyme activities mimicking peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD), enabling effective neutralization of active species such as hydroxyl radicals (center dot OH), hydrogen peroxide (H2O2), and superoxide anions (O2 center dot-). Importantly, root application of 10 mg L-1 Fe-CQDs alleviates Cd stress and promotes wheat growth in both hydroponic and soil cultures. Specifically, the levels of O2 center dot-, H2O2, and malondialdehyde (MDA) in leaf tissues decrease, whereas the non-enzyme antioxidant, reduced glutathione (GSH), increases. Cell wall thickness in the Fe-CQDs-treated group is reduced by 42.4% compared with the Cd group. Moreover, Fe-CQDs enhance the expression of genes related to antioxidants, stress resistance, Cd detoxification, and nutrient transport. Transcriptomic and metabolomic analyses show that Fe-CQDs stimulate the production of flavonoids and regulate the activity of metal transporter genes (YSL, ABC, ZIP) to maintain ROS homeostasis. These findings highlight the potential of Fe-CQDs nanozyme platforms in mitigating oxidative damage and enhancing crop growth, offering new insights into the application of nanobiotechnology in agriculture. (c) 2025 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

To elucidate the mechanism underlying the enhancement of salinity tolerance by tea polyphenols (TPs), we employed seedlings of the wheat cultivar Longchun 30 to explore the individual and combined effects of 150 mM sodium chloride (NaCl) and 25 mg L-1 (25) or 100 mg L-1 (100) TPs on growth parameters, element absorption and transport, as well as polyphenols including anthocyanin metabolism. Compared to the control, treatment with NaCl significantly reduced plant biomass, relative growth rate (by 62%), leaf area (by 61%), AS(K)(+), Na+ levels (by 38%), and AS(Ca2)(+), Na+ levels (by 54%) in wheat seedlings. Conversely, it led to an increase in TSK+, Na+ (by 88%) and TSCa2+, Na+ levels (by 257%). Moreover, the NaCl treatment diminished the antioxidant activity in the in vitro leaf extract, resulting in enhanced reactive oxygen species levels and oxidative damage in wheat leaves. Furthermore, the levels of total polyphenols (by 27%), flavonoids (by 31%), and anthocyanins (by 27%) in wheat leaves were markedly reduced under salt stress. This was accompanied by the down-regulation of the activities of 4-coumaroyl: CoA ligase (4CL), chalcone synthase, chalcone isomerase (CHI), flavanone-3-dioxygenase (F3H), dihydroflavonol reductase (DFR), and anthocyanidin synthase, along with the down-regulation of their gene expression. In contrast, individual TPs exposure resulted in weak, ineffective, or even opposite effects on most of these parameters. More importantly, the addition of TPs partly counteracted salinity-induced changes in these parameters, particularly by increasing total polyphenols, flavonoids, and anthocyanins levels, upregulating the activities of the aforementioned six enzymes, and enhancing the expression of Ta4CL, TaCHI, TaF3H, and TaDFR in wheat leaves under salinity stress. Additionally, the growth-promoting effect of 100 mg L-1 TPs on salinity-stressed seedlings was stronger than that of 25 mg L-1 TPs. Overall, TPs application significantly enhanced the growth of salinity-stressed wheat seedlings by improving K+ and Ca2+ absorption and elevating polyphenols, including flavonoids and anthocyanins levels. Moreover, the accumulation of anthocyanins in salinity-stressed wheat leaves induced by TPs was attributed to the up-regulation of the activities and gene expression of synthesis-related enzymes.

Microplastics (MPs) are important carriers of various toxic metals and can alter their toxicity pattern in agricultural soil, leading to combined pollution, therefore posing new challenges to soil pollution management and environmental risk assessment. In this study, we observed the internalization of MPs in plants and conducted incubation experiments to evaluated the effects of arsenate (As(V)) alone and in combination with polystyrene (PS) MPs on wheat seedlings (Triticum aestivum L.). Under As(V) alone and combined with PS-MP exposure, dosedependent toxicity in terms of root and stem elongation and biomass accumulation was observed. Compared with As(V) alone, the presence of PS-MPs reduced the accumulation of As in wheat roots by 11.43-58.91%, but PSMPs intensified the transport of As to the aboveground parts of wheat, increasing As accumulation in wheat stems by 27.77-1011.54%. This causes more serious mechanical damage and oxidative stress to plant cells, increasing the accumulation of reactive oxygen species and lipid peroxidation in wheat roots and upregulating the activities of antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD). In addition, the co-exposure of As(V) and PS-MPs disrupts the photosynthetic system of wheat leaves and the secretion activities of roots. Therefore, the combination of As(V) and PS-MPs caused greater damage to wheat growth. Our findings contribute to a more comprehensive assessment of the combined toxicity of MPs and heavy metal to crops.

The aim of the study was to assess the impact of plant extracts from hemp inflorescences (H10-10% and H20-20%), as well as a mixture of extracts from hemp inflorescences, sage, and tansy leaves (M10-10% and M20-20%) on phytotoxicity and selected physiological and biometric parameters of wheat seedlings, as well as the biological activity of soil in a growth chamber experiment. In all experimental combinations, a low phytotoxicity of the extracts was observed in the form of leaf tip yellowing, classified as first-degree damage or its complete absence. The plant extracts and their mixtures, except for the H20 extract, had an inhibitory effect on the development of fungal pathogens, especially Fusarium spp. The H20 extract increased the fresh and dry weight of root seedlings. The tested extracts also had a positive effect on the chlorophyll content in seedlings. The highest chlorophyll concentrations were recorded for the seedlings sprayed with the M20 extract mixture. The applied plant extracts influenced the activity of soil enzymes. The highest activity of catalase and dehydrogenases was observed after spraying seedlings with M20, while the lowest was recorded after applying H10. Of all the tested groups of soil environment compounds included in the Biolog EcoPlates test, carbohydrates and carboxylic acids were most actively utilized. Conversely, amines and amides constituted the group of compounds utilized the least frequently. The present study demonstrated the high effectiveness of plant extracts on wheat seedlings due to their biocidal action against phytopathogenic fungi and increased biological activity of the soil. This research serves as an initial phase of work, which will aim to verify the results obtained under field conditions, as well as assess the biological stability of the extracts.