Agricultural nanotechnology has emerged as an effective tool for enhancing crop yield and agricultural productivity amid the growing world population. Over the past ten years, application of nanoparticles (NPs) as nano fertilizers or bio-stimulants has been grown to enhance the morphological and biochemical parameters of various crops. The growth and development of edible crop is affected by soil iron deficiency, particularly in agricultural land that lacks sustainable management practices. This review evaluates effect of Iron oxide nanoparticles (IONPs) on agricultural plant growth. Iron is a micro-nutrient, which is essential for plants. The uptake of IONPs in plant mainly depends upon the exposure method i.e. foliar spray through leaves, soil treatment through roots and seed priming through pre-soaking of seeds. Their impact can be positive or negative depending on the variable conditions in the environment, application method, duration of exposure, concentration and size of IONPs. Various studies have shown that IONPs had affected the growth, seed germination, yield and quality of plants. Low concentration of IONPs resulted in increased rate of seed germination, plant biomass and photosynthetic pigments while at high concentration it causes toxicity by generating hydroxyl radicals leading to plant damage. This review provides an overview of IONPs effect on plants, seed germination, plant growth and morphology, yield and quality, their application in different plants, photosynthesis and toxicity.

The significant rise in soil salinity has had detrimental effects on global agricultural production, negatively impacting overall plant health and leading to a decline in productivity. As a protective response, plants have developed diverse regulatory mechanisms to counteract these adverse conditions. The mechanisms help mitigate damage caused by both osmotic and ionic stress resulting from high salinity. Given the severe threat this poses to global food security and the well-being of the world's population, scientists have dedicated decades of research to understanding how to manage salt stress. Numerous mechanisms have been identified and studied to enhance plant salt tolerance and alleviate the damage caused by salt stress. This review examines recent advancements in molecular regulatory mechanisms underlying plant salt, including salt uptake and transport, salt sensing and signalling, hormonal regulation, epigenetic modifications, genetic adaptation, and posttranslational modifications. Although current knowledge has advanced our understanding, critical gaps and controversies remain, such as the stability of epigenetic memory, the trade-off between stress tolerance and growth, hormonal crosstalk, and novel genes with uncharacterised roles in salt tolerance. To resolve these questions, further research employing techniques like GWAS, transcriptomics, transgenic and genome-editing technologies, as well as studies on energy allocation and hormonal regulation, is essential. A deeper exploration of these complex, synergistic mechanisms will pave the way for enhancing plant resilience and ensuring adaptation to increasingly challenging environmental conditions.

Inappropriate fertilization and poor management practices in citrus orchards can cause soil acidification, which may result in potential proton (H+) toxicity to citrus roots. It has been reported that boron (B) can mediate H+ detoxification in citrus; however, the mechanisms remain limited. Herein, a hydroponic experiment was employed to unravel the alleviation mechanism of B on H+ toxicity at pH 4 in trifoliate (Poncirus trifoliate (L.) Raf.) seedlings. H+ toxicity reduced cytoplasmic pH from 7.2 (control) to 6.9 and vacuolar pH from 5.6 (control) to 5.4. This severely damaged the plasma membrane (PM) and inhibited root activity by 35%. However, B supplementation restored cytoplasmic pH to 7.1 and vacuolar pH to 5.6, enhancing root activity by 52% and reducing membrane permeability (relative conductivity decreased by 28%). Mechanistically, B upregulated phosphorylated-type adenosine triphosphatase activity by 14%; conversely, it suppressed vacuolar-type adenosine triphosphatase hyperactivity by 9% to stabilize vacuolar pH. Furthermore, B restored PM integrity by increasing phospholipid (40%), glycolipid (50%) and sulfhydryl group (28%) content, critical for membrane structure and function. It is concluded that B can alleviate root growth inhibition induced by H+ toxicity via increasing the content of key components of PM, which not only repairs the damaged PM but also maintains cellular pH homeostasis through enzyme regulation. The improvement of citrus growth correspondingly safeguards the production capacity.

Cadmium (Cd) contamination in agricultural soils poses a serious threat to crop productivity and food security, necessitating effective mitigation strategies. This study investigates the role of silicon nanoparticles (SiNPs) in alleviating Cd-induced stress in maize (Zea mays L.) under controlled greenhouse conditions. Sterilized maize seeds were sown in sand-filled pots and treated with varying SiNP concentrations (0%, 0.75%, 1.5%, 3%, and 6%) with or without Cd (30 ppm). Physiological, biochemical, and antioxidant parameters were analyzed to assess plant responses. Results demonstrated that SiNPs significantly enhanced photosynthetic pigment concentrations, with chlorophyll-a, chlorophyll-b, and carotenoids increasing by 45%, 35%, and 50%, respectively, in the 6% SiNP + 30 ppm Cd treatment. Biochemical analyses revealed improved osmotic adjustment, as indicated by higher soluble protein (6.52 mg/g FW) and proline (314.43 mu mol/g FW) levels. Antioxidant enzyme activities, including superoxide dismutase, catalase, and ascorbate peroxidase, were markedly higher in SiNP-treated plants, mitigating oxidative damage. Additionally, SiNPs reduced Cd accumulation in plant tissues, suggesting a protective role in limiting metal toxicity. These findings highlight SiNPs as a promising approach for enhancing maize resilience against Cd stress, with potential applications in sustainable agriculture for improving crop health in contaminated soils.

Contamination of vegetables with heavy metals and microplastics is a major environmental and human health concern. This study investigated the role of taurine (TAE) in alleviating arsenic (As) and polyvinyl chloride microplastic (MP) toxicity in broccoli plants. The experiment followed a completely randomized design with four replicates per treatment. Plants were grown in soil spiked with MP (200 mg kg-1), As (42.8 mg kg-1), and their combination (As + MP) with or without taurine (TAE; 100 mg L-1) foliar supplementation. Results demonstrated that MP, As, and As + MP toxicity markedly decreased growth, chlorophyll content, photosynthesis, and nutrient uptake in broccoli plants. Exposure to individual or combined MP and As increased oxidative damage, indicated by elevated methylglyoxal (MG), superoxide radical (O2 & sdot;-), hydrogen peroxide (H2O2), hydroxyl radical (& sdot;OH), and malondialdehyde (MDA) levels alongside intensified lipoxygenase (LOX) activity and leaf relative membrane permeability (RMP). Histochemical analyses revealed higher lipid peroxidation, membrane damage as well as increased H2O2 and O2 center dot- levels in the leaves of stressed plants. Micropalstic and As toxicity deteriorated anatomical structures, with diminished leaf and root epidermal thickness, cortex thickness, and vascular bundle area. However, TAE improved the antioxidant enzyme activities, endogenous ascorbate-glutathione pools, hydrogen sulfide and nitric oxide levels that reduced H2O2, O2 & sdot;-, & sdot;OH, RMP, MDA, and activity of LOX. Taurine elevated osmolyte accumulation that protected membrane integrity, resulting in increased leaf relative water content and plant biomass. Plants supplemented with TAE demonstrated improved anatomical structures, resulting in diminished As uptake and its associated phytotoxicity. These findings highlight that TAE improved redox balance, osmoregulation, ion homeostasis, and anatomical structures, augmenting tolerance to As and MP toxicity in broccoli.

Chrysanthemum, a valuable ornamental flower, has limited salinity tolerance, which restricts its cultivation in salt-stressed conditions. In this study, we investigated the salt tolerance of a population derived from the salttolerant germplasm Chrysanthemum yantaiense. The parents and 91 offspring were subjected to 300 mM NaCl concentrations for 30 days. Based on the observed changes in growth and the degree of damage caused by salt stress, 15 high-resistant, 52 moderate-resistant, and 16 low-resistant strains were identified. Two offspring (i.e., YS-58 and YS-123) with contrasting salt tolerance were subjected to 15 days of salt stress, with phenotypic, physiological, and biochemical responses assessed at 5, 10, and 15 days. YS-58 demonstrated greater resilience, maintaining higher shoot fresh weight by day 10, and exhibiting significantly less growth impairment in both aboveground and belowground by day 15 compared to YS-123. Under salt stress, YS-58 accumulated lower Na* levels in leaves, while sustaining higher K* content in roots and stems. Additionally, YS-58 showed elevated proline levels, reduced soluble sugar content, and decreased malondialdehyde (MDA) accumulation, along with enhanced superoxide dismutase (SOD) activity relative to YS-123. Understanding these mechanisms will provide insights into how chrysanthemums survive under saline conditions, potentially enabling large-scale cultivation in saline soils.

Cadmium (Cd) is a hazardous trace contaminant that naturally occurs in soil and poses a global concern due to its severe impacts on human health and ecological security. In plants, tremendous efforts have been made to use some cost-effective, non-toxic, and organically made key growth regulators that partake in coping plants against adverse environmental conditions. However, the role of sorghum water extract (SWE) in attenuating the noxious effect of Cd stress is still limited in various crops including maize. In this study, different growth attributes, and physiological and biochemical indices of Cd-exposed (0, and 500 mu M) maize plants were analyzed to confirm the protective role of SWE at different concentrations (0%, 2.5%, 5%, 7.5%, and 10%). However, Cd application decreased maize growth such as plant length, number of leaves, number of roots, leaf area and biomass, and deteriorated the photosynthetic pigments such as carotenoids, chlorophyll a and b contents, decreased nutrient uptake, especially calcium and potassium ions and increased reactive oxygen species such as hydrogen peroxide. Though, medium supplementation of SWE at 10% level followed by 7.5% improved plant growth indices (plant length, number of leaves, number of roots, leaf area and biomass), nutrient uptake (calcium, potassium, nitrate, phosphate, and sulfate) and defense responses (ascorbic acid, phenolics, flavonoids) that can be attributed to enhanced physiological functioning and hermetic responses of maize plants to potential allelochemicals present in SWE. The present research highlights that the integration of these allelochemicals can be a promising approach in the future for sustainable agriculture and for keeping the environment safe at low costs.

Antimony (Sb) is a potential threat to living organisms, but very little is known on strategies manage its toxicity in plants. This study aimed to clarify the role of Fe on alleviation Sb toxicity in a metallicolous population of Salvia spinose and its mechanisms. With regard to the toxicity of Sb in plants and the importance of Fe potential in alleviation of Sb toxicity, S. spinosa was treated with 0 and 27 mg l- 1 Sb (III or V) along with 0, 50 and 300 mu M FeEDTA in a hydroponic system. The plants exposure to iron minimized the uptake of both Sb species by Salvia roots. The limitation of H2O2 generation in response to co-application of Fe with Sb was followed by counterbalancing the antioxidant enzymes (e.g. catalase, superoxide dismutase and ascorbate peroxidase), phenols, flavonoids, lipid membrane preservation, and increase of the carbohydrates and proteins contents, which altogether improved growth in Sb-stressed plants. The Sb (III) toxicity to plants was much higher than Sb (V), but 300 mu M Fe was significantly efficient in reducing Sb damages to Salvia. Altogether, application of Fe could efficiently alleviate the physiological and morphological functions in Sb-stressed Salvia.

The soil ecosystem has been severely damaged because of the increasingly severe environmental problems caused by excessive application of phosphorus (P) fertilizer, which seriously hinders soil fertility restoration and sustainable farmland development. Shoot P uptake (SPU) is an important parameter for monitoring crop growth and health and for improving field nutrition management and fertilization strategies. Achieving on-site measurement of large-scale data is difficult, and effective nondestructive prediction methods are lacking. Improving spatiotemporal SPU estimation at the regional scale still poses challenges. In this study, we proposed a combination prediction model based on some representative samples. Furthermore, using the experimental area of Henan Province, as an example, we explored the potential of the hyperspectral prediction of maize SPU at the canopy scale. The combination model comprises predicted P uptake by maize leaves, stems, and grains. Results show that (1) the prediction accuracy of the combined prediction model has been greatly improved compared with simple empirical prediction models, with accuracy test results of R 2 = 0.87, root mean square error = 2.39 kg/ha, and relative percentage difference = 2.71. (2) In performance tests with different sample sizes, two-dimensional correlation spectroscopy i.e., first-order differentially enhanced two-dimensional correlation spectroscopy (1Der-2DCOS) and two-trace 2DCOS of enhanced filling and milk stages (filling-milk-2T2DCOS)) can effectively and robustly extract spectral trait relationships, with good robustness, and can achieve efficient prediction based on small samples. (3) The hybrid model constrained by the Newton-Raphson-based optimizer's active learning method can effectively filter localized simulation data and achieve localization of simulation data in different regions when solving practical problems, improving the hybrid model's prediction accuracy. The practice has shown that with a small number of representative samples, this method can fully utilize remote sensing technology to predict SPU, providing an evaluation tool for the sustainable use of agricultural P. Therefore, this method has good application prospects and is expected to become an important means of monitoring global soil P surplus, promoting sustainable agricultural development.

AimTo examine the effect of active aluminum (Al) on copper(II) (Cu(II)) bioavailability in an acidic Cu-contaminated soil and uptake of Cu(II) by Chinese cabbage.MethodsA pot trial was conducted with Ca(OH)2 and peanut straw biochar (PB) to investigate Cu(II) uptake by Chinese cabbage. DGT (CDGT-Cu) and CaCl2 extraction methods (CCaCl2-Cu) were used to determine soil available Cu(II) and BCR sequential-extraction was used to determine Cu(II) species in the soil.ResultsThe amelioration of soil acidity with Ca(OH)2 and PB increased soil pH, promoted Chinese cabbage growth, and decreased Cu(II) uptake by plant shoots/roots. There were highly significant positive linear correlations between CDGT-Cu, CCaCl2-Cu and Cu(II) uptake by plant shoots. CDGT-Cu showed a better predictive effect for Cu(II) uptake by plant roots with a greater correlation coefficient (R2 = 0.9756). Thus, the DGT method was more effective in predicting Cu(II) uptake by plants. With increasing soil pH, Cu-HOAc and Cu-Reducible were converted to Cu-Residual, resulting in a decrease in soil Cu(II) bioavailability. The results of Structural Equation Modeling analyses showed that Al uptake by Chinese cabbage had a promoting effect on Cu(II) uptake by the plant, mainly through affecting plant growth indirectly. Soil exchangeable Al inhibited root growth (root length, root dry weight), reduced root resistance of Chinese cabbage and indirectly increased Cu(II) uptake.ConclusionsReducing Al toxicity decreased root damage and Cu(II) uptake by plant, improving the edible quality of Chinese cabbage. When remediating acidic Cu-contaminated soils, more attentions should be payed to mitigating and regulating Al toxicity.