Salinity reduces crop yields and quality, causing global economic losses. Zinc oxide nanoparticles (ZnO-NPs) improve plant physiological and metabolic processes and abiotic stress resistance. This study examined the effects of foliar ZnO-NPs at 75 and 150 mg/L on tomato Kecskeméti 549 plants to alleviate salt stress caused by 150 mM NaCl. The precipitation procedure produced ZnO-NPs that were characterized using UV-VIS, TEM, STEM, DLS, EDAX, Zeta potential, and FTIR. The study assessed TPCs, TFCs, total hydrolyzable sugars, total free amino acids, protein, proline, H₂O₂, and MDA along with plant height, stem width, leaf area, and SPAD values. The polyphenolic burden was also measured by HPLC. With salt stress, plant growth and chlorophyll content decreased significantly. The growth and development of tomato plants changed by applying the ZnO-NPs. Dosages of ZnO-NPs had a significant effect across treatments. ZnO-NPs also increased chlorophyll, reduced stress markers, and released phenolic chemicals and proteins in the leaves of tomatoes. ZnO-NPs reduce salt stress by promoting the uptake of minerals. ZnO-NPs had beneficial effects on tomato plants when subjected to salt stress, making them an alternate technique to boost resilience in saline soils or low-quality irrigation water. This study examined how foliar application of chemically synthesized ZnO-NPs to the leaves affected biochemistry, morphology, and phenolic compound synthesis with and without NaCl.

This research study investigated the production and properties of zinc oxide (ZnO) nanoparticles derived from corn husks and their priming effects on wheat plant proliferation and antioxidant mechanisms compared to the nutri-priming technique under regular irrigation and drought-stressed conditions. Transmission and scanning electron microscopy (TEM and SEM), energy-dispersive X-ray spectroscopy (EDAX), and X-ray diffraction confirmed the nanoparticles’ hexagonal morphology and typical dimensions of 51 nm. The size and stability of these nanoparticles were assessed through the size distribution and zeta potential analysis, indicating reasonable stability. Fourier-transform infrared spectroscopy (FTIR) detected the newly formed functional groups. This study emphasized the role of reactive oxygen species (ROS) and phenolic compounds in plant responses to nanoparticle treatment, particularly in detoxifying harmful radicals. The research also examined the activity of antioxidant enzymes, including peroxidase (POX), catalase (CAT), and glutathione reductase (GR), in alleviating stress caused by oxidation while subjected to various treatments, including micronutrient seed priming with DR GREEN fertilizer. Some biochemical compounds, such as total phenolics (TPCs), total flavonoids (TFCs), and total hydrolysable sugars, were estimated as well to show the effect of the different treatments on the wheat plants. The findings suggested that ZnO nanoparticles can enhance antioxidant enzyme activity under certain conditions while posing phytotoxic risks, underscoring the complexity of plant–nanoparticle interactions and the potential for improving crop resilience through targeted micronutrient applications.

High salinity reduces agriculture production and quality, negatively affecting the global economy. Zinc oxide nanoparticles (ZnO-NPs) enhance plant metabolism and abiotic stress tolerance. This study investigated the effects of 2 g/L foliar Zinc oxide NPs on Zea mays L. plants to ameliorate 150 mM NaCl-induced salt stress. After precipitation, ZnO-NPs were examined by UV–visible spectroscopy, transmission electron microscopy, scanning transmission electron microscopy, energy dispersive X-ray, and particle size distribution. This study examined plant height, stem diameter (width), area of leaves, chlorophyll levels, hydrolyzable sugars, free amino acids, protein, proline, hydrogen peroxide, and malondialdehyde. Gas chromatographic analysis quantified long-chain fatty acids, and following harvest, leaves, stalks, cobs, seeds, and seeds per row were weighed. The leaves’ acid and neutral detergent fibers were measured along with the seeds’ starch, fat, and protein. Plant growth and chlorophyll concentration decreased under salt stress. All treatments showed significant changes in maize plant growth and development after applying zinc oxide NPs. ZnO-NPs increased chlorophyll and lowered stress. ZnO-NPs enhanced the ability of maize plants to withstand the adverse conditions of saline soils or low-quality irrigation water. This field study investigated the effect of zinc oxide nanoparticles on maize plant leaves when saline water is utilized for growth season water. This study also examined how this foliar treatment affected plant biochemistry, morphology, fatty acid synthesis, and crop production when NaCl is present and when it is not.

Plants endure the repercussions of environmental stress. As the advancement of global climate change continues, it is increasingly crucial to protect against abiotic and biotic stress effects. Some naturally occurring plant compounds can be used effectively to protect the plants. By externally applying priming compounds, plants can be prompted to trigger their defensive mechanisms, resulting in improved immune system effectiveness. This review article examines the possibilities of utilizing exogenous alpha-, beta-, and gamma-aminobutyric acid (AABA, BABA, and GABA), which are non-protein amino acids (NPAAs) that are produced naturally in plants during instances of stress. The article additionally presents a concise overview of the studies’ discoveries on this topic, assesses the particular fields in which they might be implemented, and proposes new avenues for future investigation.

The study investigated the application of humic acids (HAs) and a combination of humic acids and amino acids (HA+AA) in maize under field conditions. Based on preliminary data in the literature, the aim was to investigate the effects of the two plant conditioning compounds on plant physiological parameters. In addition to measuring plant physiological parameters in the field, a complete transcriptome analysis was performed to determine exactly which genes were expressed after the treatments and in which physiological processes they play a role. Maize plants showed significant positive yield changes after two priming treatments. Genome-wide transcriptomic analysis revealed the activation of photosynthetic and cellular respiration processes, as well as protein synthesis pathways, which explains the increased yield even under extreme precipitation conditions. The results show that the HA treatment helped in water management and increased the chlorophyll content, while the HA+AA treatment led to higher protein and dry matter contents. The post-harvest tests also show that the HA+AA treatment resulted in the highest yield parameters. Functional annotation of the maize super transcriptome revealed genes related to translation processes, photosynthesis, and cellular respiration. The combined pathway analysis showed that the HA and combined treatments activated genes related to photosynthesis, carbon fixation, and cellular respiration, providing valuable in-depth insight into the usefulness of the HA and HA+AA treatments in priming. Based on the studies, we believe that the use of natural-based humic acid plant conditioners may provide a beneficial opportunity to promote renewable, regenerative agriculture.

Agricultural production is consistently threatened by stressors such as salinity. Few studies have reported on the released antioxidative enzymes and the salinity-responsive genes identified using RNA sequencing and de novo assembly in maize. To further understand the harmony between stressing the maize with a NaCl solution as a compensatory water-irrigation method and spraying regulatory zinc oxide nanoparticles (ZnO/NPs), the salinity-responsive genes were analyzed using RNA sequencing and bioinformatics tools, and the antioxidant enzymatic activities were determined. Differential expression analysis was used to uncover genes that were up-/down-regulated during the experiment. The regulatory pathways and functions of differentially expressed genes (DEGs) were estimated. Glutathione reductase/-s-transferase (GR/GST), peroxidase (POX), superoxide dismutase (SOD), and catalase (CAT) enzymes were determined spectrophotometrically. Mitigating salinity stress with 150 mM NaCl led to significant oxidative stress, markedly elevating enzyme activities: POX and GST by 275% and 254%, GR by 166%, CAT by 91%, and SOD by 56%. Treatment with ZnO/NPs alleviated this stress, decreasing enzyme activity by 61% for GST, 55% for POX, 38% for CAT, 28% for SOD, and 25% for GR. The results of RNA-seq revealed candidate genes related to changes in stressed/non-stressed maize plants, regardless of whether they were sprayed with the nanoparticles or not. This study’s results offer novel insights into the genetic traits of maize subjected to salinity stress and ZnO/nanoparticle application, thereby advancing the comprehension of how ZnO/nanoparticles might alleviate the detrimental impacts of salinity on plants whose properties were enhanced to be used in the eco-friendly synthesis of nanoparticles that were used as a bio-fertilizer in priming plants.