The present study investigates the protective role of Nitric Oxide (NO) against Copper Oxide Nanoparticles (CuONPs)-induced toxicity in two major crop species: Oryza sativa (rice) and Triticum aestivum (wheat). Seedlings were treated with green-synthesized CuONPs (500 μM), the NO donor sodium nitroprusside (SNP, 100 μM), and the NO synthesis inhibitor NG-nitro-L-arginine methyl ester (L-NAME, 500 μM), individually and in combinations, for 7 days. Exposure to CuONPs significantly reduced shoot and root fresh weights by 26

Magnesium (Mg) is a vital macronutrient that underpins multiple processes essential for plant growth, development, and survival. As the central atom in chlorophyll, Mg is indispensable for photosynthesis, the foundation of crop productivity. Beyond light capture, Mg functions as a structural, enzymatic, and regulatory ion, making it a critical mediator of plant tolerance to abiotic stresses. Drought, salinity, extreme temperatures, and nutrient deficiencies continue to limit agricultural yields, yet Mg-mediated pathways can significantly mitigate their effects. By influencing photosynthesis, ion homeostasis, osmotic adjustment, antioxidative defenses, and signal transduction, Mg reinforces multiple layers of plant stress adaptation. This review consolidates current knowledge of Mg’s roles in enhancing plant tolerance to adverse conditions, with particular emphasis on the molecular, physiological, and biochemical mechanisms underlying these roles. By integrating findings across different scales, it advances understanding of Mg-mediated stress adaptation and highlights its potential as a key factor in developing climate-resilient crop production systems. Unlike earlier works that have focused narrowly on Mg nutrition and photosynthesis, this review offers a holistic framework linking molecular insights to agronomic applications. Additionally, it provides future perspectives and research directions to bridge current knowledge gaps and guide innovation in crop breeding, nutrient management, and sustainable production systems.

Industrial products containing nano-zinc oxide (ZnONPs) enter the agricultural environment and pose hazardous effects on major crops. This study aimed to investigate the potential of 4 mM soil phosphorus (diammonium phosphate) to mitigate the adverse effects of ZnONPs stress on Triticum aestivum (wheat) and Solanum lycopersicum (tomato) seedlings. Under hydroponic conditions, 500 and 1000 µM ZnONPs were found to inhibit the growth of both crops by reducing root and shoot lengths. Additionally, physiological indices, including pigment content and endogenous nitric oxide (NO) levels, were reduced, accompanied by an increase in Zn accumulation. Enhanced activities of four antioxidant enzymes—Superoxide dismutase (EC 1.15.1.1), Catalase (EC 1.11.1.6), Ascorbate peroxidase (EC 1.11.1.11), and Glutathione-S-transferase (EC 2.5.1.18)—indicated oxidative damage in ZnONPs-exposed tomato and wheat seedling. Supplementation with phosphorus influenced NO generation, which subsequently up-regulated antioxidative enzymes and mitigated the effects on pigment content and growth. The ZnONPs-induced reactive oxygen species (ROS) were scavenged, and Zn accumulation in shoots and roots was reduced. Overall, the results suggest that phosphorus can reverse ZnONPs-induced oxidative stress by increasing endogenous NO levels, highlighting its potential for safe vegetable production in areas polluted with metal nanoparticles.

Heavy metals (HMs) pose a significant ecological risk due to their enduring presence in the ecosystem. They become more prevalent as a result of urbanization and industrialization, disrupting critical functions of plant life such as photosynthesis, seedling growth, and germination. Understanding the impact of HMs and nanoparticle exposure on plants is crucial for developing effective strategies to mitigate their potential hazards. Therefore, an effort was made to elucidate the impact of biosynthesized Ag NPs (nanoparticles) and ZnO NPs versus their precursor metal salts, AgNO3 and ZnSO4, respectively on two Asteraceous plants, Mexican marigold (Tagetes erecta L.) and Zinnia (Zinnia elegans Jacq.) in hydroponic solution by monitoring the changes in photosynthetic pigments and their associated photochemistry of photosystem II along with the anatomical attributes. In the present study, two concentrations (50 mu M and 100 mu M) for each treatments viz., AgNO3, Ag NPs, ZnSO4 and ZnO NPs were given to the seedlings. Metal salts were found to be more toxic than their nanoparticles, and this was manifested in terms of reduction in photosynthetic pigments, especially chlorophylla content (by 32% in marigold and 27% in Zinnia upon exposure to 100 mu M of AgNO3, respectively) in both test seedlings. Reduction in chlorophyll fluorescence parameters was also found under metal as well as nanoparticle toxicity. In contrast, energy flux parameters such as absorption of photon per active reaction centre (ABS/RC), trapped energy flux per active reaction centre (TR0/RC), electron transport flux per active reaction centre (ET0/RC) and energy dissipation flux per active reaction centre (DI0/RC) increased significantly to cope with stress toxicity. Similarly, metals and nanoparticles also distorted the anatomy of the root and leaf, and the effect was more intense under AgNO3 treatment than with ZnSO4 in Zinnia. In conclusion, Zinnia seedlings were more resilient towards all the tested conditions, which might be attributed to their adaptability to various environmental factors, indicating their potential for thriving in diverse climates.

Environmental health is a major concern around the world due to the exponential increase in pollutant discharges into the environment from industrial and agricultural activities. Endocrine-disrupting chemicals (EDCs) are a broad category of natural or synthetic substances with properties that may cause endocrine disruption in an intact organism, its progeny, or (sub)populations. Everyday products such as plastics, personal care products, and cleaning agents, as well as pesticides, herbicides, and industrial chemicals, may contain EDCs. These chemicals can enter the environment through air and water pollution and can accumulate in the food chain, leading to widespread exposure in both humans and wildlife. EDCs can disturb the normal functioning of plants, humans, and animals. These compounds can enter in plant through roots and atmospheric air and hinder the activity of several enzymes and hormones. Several studies showed that EDCs have negatively affected the various physiological processes of plants such as photosynthesis, which are discussed in this chapter. To tackle the challenges posed by EDCs, numerous organizations and governments have urged for enhanced research, regulation, and public awareness of these chemicals. Certain countries have implemented legislation to limit the use of EDCs in specific products, and several manufacturers have voluntarily removed EDCs from their products. Nonetheless, further action is required to minimize exposure to EDCs and safeguard human and environmental health. In summary, EDCs are a complex and prevalent group of environmental pollutants that pose significant risks to human and wildlife health. Thus this chapter will focus on how EDCs exposure induces alteration in the plant's germination, growth, and physiological trait.

The phytohormone auxin acts as an important signaling molecule having regulatory functions during the growth and development of plants. Reactive oxygen species (ROS) are also known to perform signaling functions at low concentrations; however, over-accumulation of ROS due to various environmental stresses damages the biomolecules and cell structures and leads to cell death, and therefore, it can be said that ROS act as a double-edged sword. Nitric oxide (NO), a gaseous signaling molecule, performs a wide range of favorable roles in plants. NO displays its positive role in photomorphogenesis, root growth, leaf expansion, seed germination, stomatal closure, senescence, fruit maturation, mitochondrial activity and metabolism of iron. Studies have revealed the early existence of these crucial molecules during evolution. Moreover, auxin, ROS and NO together show their involvement in various developmental processes and abiotic stress tolerance. Redox signaling is a primary response during exposure of plants to stresses and shows a link with auxin signaling. This review provides updated information related to crosstalk between auxin, ROS and NO starting from their evolution during early Earth periods and their interaction in plant growth and developmental processes as well as in the case of abiotic stresses to plants.

Oat (Avena sativa L.) is a unique multifaceted crop used for fodder and grain purpose. It’s grain has tremendous potential to offer health benefits, especially with the heightened emphasis on nutrition and food security. With this aim, quality traits were investigated among 62 oat genotypes, demonstrating significant variation. The biochemical analysis was conducted in laboratory of department of Genetics and Plant Breeding of CCS Haryana Agricultural University, Hisar during 2019–21. Quality parameters depicted a wide range for seed crude protein (8.16–19.18%), forage crude protein (5.17–11.42%), phenol (0.61–1.22%), beta-glucan content (0.32–7.55%), total soluble sugar (4.90–8.49%), reducing sugar (1.07–4.28%) and non-reducing sugar (2.02–6.38%). The current research covered wide and powerful analytical approaches that helped to underpin the selection of the most promising genotypes and evaluated the contribution of different traits to heterogeneity. Furthermore, non-reducing sugar, reducing sugar and seed crude protein were emerged to be the major contributors of PC1, PC2 and PC3, respectively. The genotypes GP 492, HFO 1107, HFO 1003, HFO 1016, OS 403, HFO1105 and HFO 806 were the best performing based on quality parameters. Promiscuous genotypes can serve as pioneers in oat improvement programs, enabling the enhancement of nutritional value. These insights expand the prospects for the food industry and hence appraise the significance of oats among other cereals.

This study aimed to investigate the phytotoxic effect of copper (Cu) and copper nanoparticles (CuONPs) and ameliorative potential of nitric oxide (NO) against these toxic materials in Sorghum vulgare Pers. seedlings. Data suggested that exposure of Cu and CuONPs significantly reduced growth, chlorophyll, carotenoids and protein in root and shoot, which coincided with increased Cu accumulation. However, addition of sodium nitroprusside (SNP, a donor of NO) lowered Cu and CuONPs mediated toxicity through restricting Cu accumulation and improving photosynthetic pigments and total soluble protein contents. Data further suggested that exposure of Cu and CuONPs significantly increased hydrogen peroxide (H2O2), superoxide radicals (O2•-), and malondialdehyde (MDA) contents. Enhanced level of oxidative stress severely inhibited the enzymatic activities of glutathione reductase (GR), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR) but enhanced superoxide dismutase (SOD) and catalase (CAT) activity. However, addition of SNP positively regulated antioxidants enzymes activity, particularly the enzymes involved in the ascorbate-glutathione cycle to overcome Cu- and CuONPs-induced stress in Sorghum seedlings. Further, Cu and CuONPs enhanced accumulation of free proline through inducing Δ1-pyrroline-5-carboxylate synthetase (P5CS) activity while lowering the proline dehydrogenase (PDH) activity. However, addition of SNP reversed these responses. Therefore, overall results revealed that SNP has enough potential of reducing the toxicity of Cu and CuONPs in Sorghum seedlings through regulation of proline metabolism and activity of enzymes of the ascorbate-glutathione cycle. These findings can be employed in developing new resistant varieties of Sorghum having enhanced tolerance against Cu or CuONP stress and improved productivity.

The study aims to optimize cellulase (CMCase) production by Aspergillus flavus using wheat straw, an abundantly available lignocellulosic waste, as a substrate. Three parameters, i.e., nitrogen content (0.25 to 1%), fungal inoculum (0.25 to 1%), and duration (3 to 12 days), were optimized for maximum CMCase production using Response surface methodology-Box Behnken design (RSM-BBD). The quadratic response surface was suitable, and the model was significant. However, higher-order machine learning (ML) models were applied as the RSM-BBD model had a low R2 value (0.85) and negative predicted R2 value (−0.82). The supervised ML regression models, i.e., Artificial neural network (ANN) with Bayesian Regularization Neural Network (BRNN) and Radial Basis function Neural Network (RBFNN), Support vector machine (SVM) with Polynomial kernel (SPK), and Gaussian kernel (SGK), and Gaussian process learner (GPL) with the exponential kernel (GEK) and squared exponential kernel (GSEK) were applied. The RBFNN was the best performing model with a mean squared error (MSE) value of 0.0025 and an R2 value of 0.98. The maximum CMCase production of 13.89 U/gds was at yeast extract 0.25%, fungal inoculum 0.625%, and duration of 12 days. There was almost a threefold increase in CMCase production after optimization compared to the screening experiments (4.7 U/gds).

The individual impact of silicon (Si) and nitric oxide (NO, as sodium nitroprusside) on metal toxicity in various plant species has been well documented; however, their combined action in the regulation of metal stress has never been tested yet. Therefore, this study investigates the effects of the combined application of Si and NO in the mitigation of Cd toxicity in wheat seedlings. Seedlings grown on Cd has a significantly declined growth due to an increased accumulation of Cd and oxidative stress markers (due to downregulation of antioxidant defense system particularly ascorbate-glutathione cycle) and a decreased accumulation of NO and Si. Additionally, the altered leaf and root structures resulted into a declined photosynthetic efficiency. However, the addition of Si and NO alone as well as combined significantly alleviated Cd toxicity in wheat seedlings by lowering the accumulation of Cd and oxidative stress markers and improving leaf and root structures, which are collectively responsible for a better photosynthetic rate under Cd toxicity, and hence an improved growth was noticed. Particularly, the application of Si and NO in combination lowered the oxidative stress markers via upregulating the antioxidant defense system (particularly AsA-GSH cycle) suggesting the increased efficacy of Si + NO against the Cd toxicity in wheat seedlings as compared to their alone treatments.

Aggrandized technological and industrial progression in past decades have occasioned immense depreciation in the quality of environment and ecosystem, majorly due to augmentation in the number of obnoxious pollutants incessantly being released in soil, water or air. Arsenic (As) is one such hazardous metalloid contaminating the environment which has the potential to detrimentally affect the life on earth. Even in minute quantity, As is known to cause various critical diseases in humans and toxicity in plants. Recent studies on nanoparticles (NPs) approve of their ability to qualify the criterion of becoming a potent tool for mitigating As-induced phytotoxicity. Nanoparticles are reported to promote plant growth under As-stress by stimulating various alterations at physiological, biochemical, and molecular levels. In this review, we provide an up-to-date compilation of research that has been carried out in comprehending the mechanisms utilized by nanoparticles including controlled As uptake and distribution in plants, maintenance of ROS homeostasis during stress and chelation and vacuolar sequestration of As so as to reduce the severity of toxicity induced by As, and potential areas of research in this field will also be indicated for future perspectives.

Flavonoids are characterized as the low molecular weight polyphenolic compounds universally distributed in planta. They are a chemically varied group of secondary metabolites with a broad range of biological activity. The increasing amount of evidence has demonstrated the various physiological functions of flavonoids in stress response. In this paper, we provide a brief introduction to flavonoids' biochemistry and biosynthesis. Then, we review the recent findings on the alternation of flavonoid content under different stress conditions to come up with an overall picture of the mechanism of involvement of flavonoids in plants' response to various abiotic stresses. The participation of flavonoids in antioxidant systems, flavonoid-mediated response to different abiotic stresses, the involvement of flavonoids in stress signaling networks, and the physiological response of plants under stress conditions are discussed in this review. Moreover, molecular and genetic approaches to tailoring flavonoid biosynthesis and regulation under abiotic stress are addressed in this review.

This study aimed to investigate the phytotoxic effect of copper (Cu) and copper nanoparticles (CuONPs) and ameliorative potential of nitric oxide (NO) against these toxic materials in Sorghum vulgare Pers. seedlings. Data suggested that exposure of Cu and CuONPs significantly reduced growth, chlorophyll, carotenoids and protein in root and shoot, which coincided with increased Cu accumulation. However, addition of sodium nitroprusside (SNP, a donor of NO) lowered Cu and CuONPs mediated toxicity through restricting Cu accumulation and improving photosynthetic pigments and total soluble protein contents. Data further suggested that exposure of Cu and CuONPs significantly increased hydrogen peroxide (H2O2), superoxide radicals (O2•−), and malondialdehyde (MDA) contents. Enhanced level of oxidative stress severely inhibited the enzymatic activities of glutathione reductase (GR), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR) but enhanced superoxide dismutase (SOD) and catalase (CAT) activity. However, addition of SNP positively regulated antioxidants enzymes activity, particularly the enzymes involved in the ascorbate-glutathione cycle to overcome Cu- and CuONPs-induced stress in Sorghum seedlings. Further, Cu and CuONPs enhanced accumulation of free proline through inducing Δ1-pyrroline-5-carboxylate synthetase (P5CS) activity while lowering the proline dehydrogenase (PDH) activity. However, addition of SNP reversed these responses. Therefore, overall results revealed that SNP has enough potential of reducing the toxicity of Cu and CuONPs in Sorghum seedlings through regulation of proline metabolism and activity of enzymes of the ascorbate-glutathione cycle. These findings can be employed in developing new resistant varieties of Sorghum having enhanced tolerance against Cu or CuONP stress and improved productivity.

In agriculture, abiotic stress is one of the critical issues impacting the crop productivity and yield. Such stress factors lead to the generation of reactive oxygen species, membrane damage, and other plant metabolic activities. To neutralize the harmful effects of abiotic stress, several strategies have been employed that include the utilization of nanomaterials. Nanomaterials are now gaining attention worldwide to protect plant growth against abiotic stresses such as drought, salinity, heavy metals, extreme temperatures, flooding, etc. However, their behavior is significantly impacted by the dose in which they are being used in agriculture. Furthermore, the action of nanomaterials in plants under various stresses still require understanding. Hence, with this background, the present review envisages to highlight beneficial role of nanomaterials in plants, their mode of action, and their mechanism in overcoming various abiotic stresses. It also emphasizes upon antioxidant activities of different nanomaterials and their dose-dependent variability in plants' growth under stress. Nevertheless, limitations of using nanomaterials in agriculture are also presented in this review.