Nitric oxide (NO) is a multifunctional signaling molecule in plants, playing key roles in germination, microbial symbiosis, and nodule formation. However, its instability requires innovative approaches, such as using nanoencapsulated NO donors, to prolong its effects. This study evaluated the impact of treating soybean (Glycine max) seeds with the NO donor S-nitrosoglutathione (GSNO), encapsulated in polymeric nanoparticles, on the germination, nodulation, and plant growth. Seeds were treated with free GSNO, chitosan nanoparticles with/without NO (NP CS-GSNO/NP CS-GSH, where GSH is glutathione, the NO donor precursor), and alginate nanoparticles with/without NO (NP Al-GSNO/NP Al-GSH). Chitosan nanoparticles (positive zeta potential) were smaller and released NO faster compared with alginate nanoparticles (negative zeta potential). The seed treatment with NP CS-GSNO (1 mM, related to GSNO concentration) significantly improved germination percentage, root length, number of secondary roots, and dry root mass of soybean compared with the control. Conversely, NP CS-GSH resulted in decreased root and shoot length. NP Al-GSNO enhanced shoot dry mass and increased the number of secondary roots by approximately threefold at the highest concentrations. NP CS-GSNO, NP Al-GSNO, and NP Al-GSH increased S-nitrosothiol levels in the roots by approximately fourfold compared with the control. However, NP CS-GSNO was the only treatment that increased the nodule dry mass of soybean plants. Therefore, our results indicate the potential of chitosan nanoparticles to improve the application of NO donors in soybean seeds.

Seeds are the cornerstone of agricultural crop production. They are sources of many valuable materials that can be used to convert bulk materials into nanoforms, thus supporting sustainability in nanomaterial (NM) synthesis and circular farming. The use of seeds in innovative nanotechnology is based on the theoretical knowledge about seed–NM interactions and NM toxicity on seeds. The results show that the internalization of NMs into seeds and their effect on seed physiology depend on several properties of both the NM and the plant species. Nanotechnology innovations including seed-associated strategies for improving abiotic stress tolerance, facilitating pathogen protection, effectively transferring genetic information into embryos, and converting seed oils into biodiesel have been recently developed. This review aims to provide an overview of the current knowledge regarding the complex, multidirectional interactions of seeds with NMs, and suggest directions for future research of seed nanobiology.

Zinc oxide nanoparticles (ZnO NPs) are promising tools for improving Zn delivery to plants, but their efficiency depends strongly on their physicochemical properties. Here, we compared four ZnO NP formulations differing in origin, particle size and surface charge for their short-term interactions with Arabidopsis thaliana roots. Seedlings were exposed to 2.5–25 mg/L ZnO NPs for 2 h, and root Zn-associated fluorescence was visualized using ZinPyr-1. All formulations increased fluorescence in a concentration-dependent manner, but positively charged, chemically synthetized ZnO NPs (CHEM1, CHEM2) were more effective than negatively charged formulations. CHEM2, which is larger and less positive than CHEM1, induced the strongest response, particularly in the root tip and middle root zone, and produced a distinct Zn-associated signal in vascular tissues. No significant increase was detected near the root–shoot junction, indicating limited redistribution during short-term exposure. Plant exposure also altered suspension chemistry. In case of CHEM2, it caused the strongest acidification and Zn depletion, although changes in suspension Zn did not consistently correspond to root fluorescence or pH. These findings demonstrate that Zn delivery from ZnO NPs is highly formulation-dependent and likely reflects the combined influence of surface charge, particle size, dissolution and root–particle interactions. Thus, physicochemical properties should be carefully considered when designing ZnO nanomaterials for plant Zn delivery.

Isocitrate lyase (ICL) plays a central role in mobilizing seed lipid reserves by converting fatty acids into sugars during early seedling development. In the present study, a three-dimensional model of ICL was constructed to identify potential ligands through virtual screening simulations. In vitro and in vivo assays were conducted to evaluate the effects of the selected ligands, itaconate and tartrate, on the development of various crop and weed species differing in seed lipid content. The effects of itaconate were assessed in 5-day-old seedlings grown in germination boxes (50–1000 µM) and in 14-day-old seedlings grown in pots under greenhouse conditions (0.008–16.25 g/dm³). Overall, species with higher seed lipid content exhibited greater sensitivity to itaconate inhibition, particularly during early seedling growth. ICL activity extracted from sensitive species was inhibited by itaconate, whereas tartrate had no effect. As a consequence of its primary action in the glyoxylate cycle, itaconate impaired gluconeogenesis in cotyledons of Euphorbia heterophylla seedlings, reducing sugar export to the roots and thereby inhibiting seedling development. However, the concentrations required to achieve weed mortality in greenhouse-grown plants were substantially high, indicating limited herbicidal efficacy of itaconate. Structural modification of itaconate to enhance interaction with ICL catalytic residues or improve cellular uptake may yield more effective herbicidal candidates. The detailed protein-ligand interaction data provided by the ArThaICL docking model developed in this study represents a valuable tool to guide this optimization process.