The use of nanotechnology can ensure food security via improving crop production. Nanoparticles have the ability to enhance growth and yield of different plants such as fenugreek (Trigonella foenum-graecum) (Fabaceae). The present work aims to study the role of silver nanoparticles (AgNPs) on growth, some biochemical aspects, and the yield both quantitatively and qualitatively of fenugreek plant. AgNPs were synthesized by chemical reduction of silver nitrate with trisodium citrate. Foliar application of AgNPs with different concentrations (20, 40, and 60 mg/l) improved the growth parameters of fenugreek plant (e.g., shoot length, number of leaves/plant, and shoot dry weight) and increased some biochemical aspects such as photosynthetic pigment (chlorophyll a, chlorophyll b, and carotenoids) and indole acetic acid (IAA) contents thus enhanced the yield quantity (number of pods/plant, number of seeds/pod, weight of seeds/plant, and seed index) and quality (carbohydrate%, protein%, phenolics, flavonoids, and tannins contents) of the yielded seeds as well as increasing antioxidant activity of the yielded seeds. The most effective treatment was 40 mg/l as it caused the highest increases in the studied parameters.

Background: Shortage of water is a major problem facing Egypt; thus, it becomes necessary to use non-traditional sources of water such as saline water in irrigation. Overcoming the adverse effects of saline water and enhancing plant tolerance to salinity stress is the main challenge for increasing plant growth and productivity. Using a natural compound such as cysteine amino acid has an important effect in alleviating the adverse effect of salinity stress on different plant crops. Materials and methods: Two pot experiments were carried out during two successive summer seasons to study the beneficial role of cysteine (0, 20, and 40 mg/l) in enhancing growth, some metabolic process, and seed yield quality and quantity of soybean plant grown under salinity stress (0, 3000, and 6000 mg/l). Results: Salinity stress (3000 and 6000 mg/l) caused decreases in soybean growth criteria (plant height, number of branches and leaves/plant, dry weight of leaves and stem/plant), photosynthetic pigments and some element contents (nitrogen (N), phosphorus (P), and potassium (K)), and seed yield and yield components (number of pods/plant, weight of pods/plant and number of seeds/plant) as well as oil%. Meanwhile, proline, H₂O₂ and MDA contents, and superoxide dismutase activity were gradually increased by increasing salinity level. On the other hand, cysteine treatments improved growth and yield of soybean plant either irrigated with tap water or saline water. Cysteine treatments could alleviate the adverse effect of salinity stress on growth and yield of soybean plant through increasing photosynthetic pigments; proline content; N, P, and K contents; superoxide dismutase and catalase activities; and oil% accompanied by decreases in H₂O₂ and MDA contents as compared with their corresponding controls. In addition, cysteine treatments and/or salinity stress exhibited differences in protein pattern from 112 to 19 kD molecular weight. The appearance of new protein bands reflected the expression of cysteine treatments and salinity stress. Conclusion: Cysteine treatments had a beneficial role in alleviating the adverse effect of salinity stress on soybean plant. Forty milligrams per liter of cysteine was the most effective treatment in enhancing salinity tolerance of soybean plant.

Nitric oxide (NO) is a well-accepted signaling molecule that has regulatory effects on plants under various stresses. Salinity is a major issue that adversely affects plant growth and productivity. The current study was carried out to investigate changes in the growth, biochemical parameters, and yield of wheat plants in response to NO donors, namely sodium nitroprusside (SNP) (2.5 and 5.0 mM) and arginine (10 and 20 mM), under two salinity levels (1.2 mM and 85.5 mM NaCl). Salinity stress significantly decreased the lengths and weights of plant parts (shoot, tiller, and root) and reduced the flag leaf area, photosynthetic pigments, indole acetic acid (IAA), and yield and its components. Moreover, salt stress induced a significant accumulation of some osmoprotectants (total soluble sugars (TSS) and amino acids, especially proline) and triggered the accumulation of hydrogen peroxide (H₂O₂) and lipid peroxidation in wheat leaves. In contrast, arginine and SNP treatments significantly mitigated the negative impacts of salinity on growth and productivity via enhancing photosynthetic pigments, nitrate reductase, phenolic compounds, IAA, TSS, free amino acids, and proline. In addition, SNP and arginine potentially reduced oxidative damage by decreasing H₂O₂ and lipid peroxidation through the induction of antioxidant enzymes. The individual amino acid composition of wheat grains under the interactive effect of salinity and NO sources has been scarcely documented until now. In this study, the NO sources restrained the reduction in essential amino acids (isoleucine and lysine) of wheat grains under salinity stress and further stimulated the contents of non-essential and total aromatic amino acids. Interestingly, the applied protectants recovered the decrease in arginine and serine induced by salinity stress. Thus, SNP or arginine at the levels of 5.0 and 20 mM, respectively, had a profound effect on modulating the salt stress of wheat throughout the life cycle.

Background: Melatonin, an indoleamine compound, has the ability to regulate a lot of physiological and biochemical processes under different environmental stresses such as drought stress. Materials and methods: So, this investigation was done to study the physiological role of melatonin on Moringa oleifera plants grown in sandy soil at normal and drought stress. Results: Subjecting M. oleifera plant to drought stress caused significant decreases in growth, photosynthetic pigment, indole acetic acid (IAA), element contents, yield, and yield attributes, meanwhile increased lipid peroxidation is expressed as malondialdehyde (MDA) and various antioxidant enzymes as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX). On the other hand, foliar treatment with different concentrations of melatonin significantly increased growth parameters, yield quantity, and quality of M. oleifera plant at normal and drought-stressed conditions via improving photosynthetic pigments (IAA), phenolic and element contents, and antioxidant enzyme systems, whereas declined malondialdhyde (MDA) contents as compared with their corresponding untreated controls (M0). Foliar treatment with 100 mM melatonin showed the greatest growth criteria and yield components of M. oleifera plants at either normal irrigation or under drought stress. This concentration also improved amino acid constituents of the yielded M. oleifera plants compared with other concentrations under normal and stress conditions. Conclusion: We can conclude that spraying M. oleifera with melatonin could alleviate the reduced effect of drought stress.

Background: Using of nanoparticles in various aspects of life including agriculture, medicine and industry is very crucial. One of the important source for Fe nutrition in plants is Iron oxide nanoparticles (Fe₃O₄NPs) due to its efficiency in releasing under different pH range. Thus, in the Model Farm of National Research Centre Egypt at El Tour South Sinai, a field experiment was carried out, to study the effect of different concentration of Fe₃O₄NPs (0, 20, 40, 60 ppm) on the physiological parameters and the nutritive value of Moringa under saline condition.Results: The obtained results indicate that foliar spraying of Fe₃O₄NPs significantly promote growth (plant height, branches leaves number per plant, leaf area, stem diameter and biomass). Foliar treatment also increased photosynthetic pigments (chlo.a,chlob,chloa/b and carotenoids) and indole acetic acid (IAA) contents comparing with control. Hydrogen peroxide and lipid peroxidation contents ofMoringa oleiferaleaves were decreased significantly as compared with control plant. The maximum activities of antioxidant enzymes Peroxidase (POX), poly phenol oxidase (PPO), super oxide dismutase (SOD) and nitrate reductase (NR) were observed in plants treated with 40 ppm. Different concentrations of Fe₃O₄NPs increased significantly crude protein, crude fiber and ash percentages as well as, some nutrient contents of moringa leaves (N, P, K and K/Na) compared with untreated control plants, meanwhile decreased Na contents.Conclusion: Treatment ofMoringa oleiferaplant with Fe₃O₄NPs at different concentrations greatly decrease the harmful effect of salinity on growth by its promotive role on different studied biochemical and physiological aspects.