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"Ibrahim, Omar M."
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Role of Nanoparticles in Enhancing Crop Tolerance to Abiotic Stress: A Comprehensive Review
by
Desoky, El-Sayed M.
,
AbuQamar, Synan F.
,
Ibrahim, Omar M.
in
Abiotic stress
,
Agricultural production
,
Agriculture
2022
Plants are subjected to a wide range of abiotic stresses, such as heat, cold, drought, salinity, flooding, and heavy metals. Generally, abiotic stresses have adverse impacts on plant growth and development which affects agricultural productivity, causing food security problems, and resulting in economic losses. To reduce the negative effects of environmental stress on crop plants, novel technologies, such as nanotechnology, have emerged. Implementing nanotechnology in modern agriculture can also help improve the efficiency of water usage, prevent plant diseases, ensure food security, reduce environmental pollution, and enhance sustainability. In this regard, nanoparticles (NPs) can help combat nutrient deficiencies, promote stress tolerance, and improve the yield and quality of crops. This can be achieved by stimulating the activity of certain enzymes, increasing the contents (e.g., chlorophyll) and efficiency of photosynthesis, and controlling plant pathogens. The use of nanoscale agrochemicals, including nanopesticides, nanoherbicides, and nanofertilizers, has recently acquired increasing interest as potential plant-enhancing technologies. This review acknowledges the positive impacts of NPs in sustainable agriculture, and highlights their adverse effects on the environment, health, and food chain. Here, the role and scope of NPs as a practical tool to enhance yield and mitigate the detrimental effects of abiotic stresses in crops are described. The future perspective of nanoparticles in agriculture has also been discussed.
Journal Article
Biosynthesized silver nanoparticles mediated by Ammi visnaga extract enhanced systemic resistance and triggered multiple defense-related genes, including SbWRKY transcription factors, against tobacco mosaic virus infection
2024
Background
Tobacco mosaic virus (TMV) is a highly infectious plant virus that affects a wide variety of plants and reduces crop yields around the world. Here, we assessed the effectiveness of using
Ammi visnaga
aqueous seed extract to synthesize silver nanoparticles (Ag-NPs) and their potential to combat TMV. Different techniques were used to characterize Ag-NPs, such as scanning and transmission electron microscopy (SEM, TEM), energy-dispersive X-ray spectroscopy (EDS), fourier transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS).
Results
TEM demonstrated that the synthesized Ag-NPs had a spherical form with an average size of 23–30 nm and a zeta potential value of -15.9 mV, while FTIR revealed various functional groups involved in Ag-NP stability and capping. Interestingly, the Pre-treatment of tobacco plants (protective treatment) with Ag-NPs at 100–500 µg/mL significantly suppressed viral symptoms, while the Post-treatment (curative treatment) delayed their appearance. Furthermore, protective and curative treatments significantly increased chlorophyll a and b, total flavonoids, total soluble carbohydrates, and antioxidant enzymes activity (PPO, POX and CAT). Simultaneously, the application of Ag-NPs resulted in a decrease in levels of oxidative stress markers (H
2
O
2
and MDA). The RT-qPCR results and volcano plot analysis showed that the Ag-NPs treatments trigger and regulate the transcription of ten defense-related genes (
SbWRKY-1
,
SbWRKY-2
,
JERF-3
,
GST-1
,
POD
,
PR-1
,
PR-2
,
PR-12
,
PAL-1
, and
HQT-1
). The heatmap revealed that
GST-1
, the primary gene involved in anthocyanidin production, was consistently the most expressed gene across all treatments throughout the study. Analysis of the gene co-expression network revealed that
SbWRKY-1
9 was the most central gene among the studied genes, followed by
PR-12
and
PR-2
.
Conclusions
Overall, the reported antiviral properties (protective and/or curative) of biosynthesized Ag-NPs against TMV lead us to recommend using Ag-NPs as a simple, stable, and eco-friendly agent in developing pest management programs against plant viral infections.
Journal Article
Breaking Barriers: Modulation of Tumor Microenvironment to Enhance Bacillus Calmette–Guérin Immunotherapy of Bladder Cancer
2024
The clinical management of bladder cancer continues to present significant challenges. Bacillus Calmette–Guérin (BCG) immunotherapy remains the gold standard of treatment for non-muscle invasive bladder cancer (NMIBC), but many patients develop recurrence and progression to muscle-invasive disease (MIBC), which is resistant to BCG. This review focuses on the immune mechanisms mobilized by BCG in bladder cancer tumor microenvironments (TME), mechanisms of BCG resistance, the dual role of the BCG-triggered NFkB/TNFα/PGE2 axis in the regulation of anti-tumor and tumor-promoting aspects of inflammation, and emerging strategies to modulate their balance. A better understanding of BCG resistance will help develop new treatments and predictive biomarkers, paving the way for improved clinical outcomes in bladder cancer patients.
Journal Article
Optimizing phosphorus released in calcareous soil amended with bone char and bone ash using response surface methodology and desirability function
2025
This study evaluated the optimization of phosphorus (P) released in calcareous soil-amended with bone ash (BA) and bone char (BC) compared to phosphate rock (PR) and single superphosphate (SSP) using a central composite design and desirability function. Incubation experiment was conducted (≃30 °C) to investigate the effects of P-levels (PL, 1000–4000 mg P/kg soil) and incubation time (14–90 days) on available-P, soluble-P, -Ca²⁺, -Mg²⁺, and soil-pH. Wetting and drying cycles were applied using distilled water (DW) and acidified water (AW). Results revealed a significant increase in soil phosphorus availability and solubility over time, particularly at higher PL. AW was more effective than DW in increasing available-P and soluble-P, -Ca²⁺, and -Mg²⁺, while reducing soil-pH and incubation time. Regardless of SSP behavior due to its high solubility, maximum amounts of available-P in BA-, BC-, and PR-amended soil for DW application were 40.92, 31.53, and 16.74 mg/kg at 40.6, 55.8, and 14 days, respectively, with PL of 3850 mg/kg for BA and 4000 mg/kg for BC and PR. For soluble-P, maximum amounts were 3.1, 2.62, and 0.85 mg/kg with AW application after incubation times of 36.8, 63.4, and 90 days, respectively, which were higher than DW application. BA-amended soil with DW and AW applications exhibited optimal responses for available and soluble phosphorus, higher than BC-amendment. PL and incubation time interactions were pronounced in enhancing the studied parameters. The study concluded that AW, simulating rhizosphere acidification, significantly optimized P-release and related parameters compared to DW. This perspective requires further research for broader applications, especially for its applications in large-scale agricultural systems. Generally, BA and BC redistributed the phosphorus solubility and availability in soil, subsequently enhancing soil fertility and sustainability as an eco-friendly phosphate fertilizer.
Journal Article
Molecular diversity and genetic potential of new maize inbred lines across varying sowing conditions in arid environment
by
Hassanin, Abdallah A.
,
Ibrahim, Omar M.
,
Kamara, Mohamed M.
in
631/449/2491
,
631/449/711
,
Arid environments
2025
Developing high-yielding and resilient maize hybrids is essential to ensure its sustainable production with the ongoing challenges of considerable shifts in global climate. This study aimed to explore genetic diversity among exotic and local maize inbred lines, evaluate their combining ability, understand the genetic mechanisms influencing ear characteristics and grain yield, and identify superior hybrids suited for timely and late sowing conditions. Seven local and exotic maize inbred lines were genotyped using SSR (Simple Sequence Repeat) markers to assess their genetic diversity. These diverse lines were utilized to develop 21 F1 hybrids using a diallel mating design. These hybrids, alongside a high-yielding commercial check (SC-10), were evaluated under field conditions across two growing seasons under timely and late sowing conditions. The results showed that sowing date, assessed hybrids, and their interaction significantly influenced all measured agronomic traits. Notably, late sowing reduced plant height, ear characteristics, and, ultimately, grain yield. Several hybrids, particularly L101 × L103, L101 × L105, L104 × L105, and L104 × L107 under timely sowing, and L101 × L105 and L104 × L107 under late sowing, surpassed the agronomic performance of check commercial hybrid. Inbred lines L101 and L103 emerged as superior combiners for ear traits and yield, while line L106 showed promise for breeding shorter-stature plants. Hybrid combinations L101 × L105, L104 × L107, and L106 × L107 were identified as specific good combiners for grain yield and related traits under both sowing conditions, indicating their potential for commercial development. Strong positive associations were observed between grain yield and certain agronomic traits highlighting their utility for indirect selection in early breeding generations.
Journal Article
Under cadmium stress, silicon has a defensive effect on the morphology, physiology, and anatomy of pea (Pisum sativum L.) plants
by
El-Okkiah, Samira A. F.
,
Taha, Mohamed A.
,
Ibrahim, Omar M.
in
Abnormalities
,
Agricultural production
,
Agriculture
2022
Soil pollution with cadmium (Cd) is a serious threat to plant growth and development. On the other hand, silicon (Si) can support plants to cope with Cd stress. However, the Cd stress mitigating impact of Si reduction in pea ( Pisum sativum L.) is not known. The objective of this study is to see if and how Si can reduce Cd toxicity. To the end, a greenhouse pot experiment was performed twice during the 2018/2019 and 2019/2020 seasons to investigate the effect of Si on the growth, anatomy, and biochemistry of Cd stressed peas plants. Cd exposure increased the contents of Cd ions in the root and shoot of pea plants. Consequentially, Cd accumulation in pea tissue significantly reduced plant growth i.e., plant height, leaf area, and shoot and root dry weights. The effect of Cd was concentration-dependent, where at low concentration (50 mg/kg soil), the plant height was 94.33 and 97.33cm and at high concentration (100 mg/kg soil), it was 89.0 and 91.0 cm in the two seasons, respectively. This growth reduction can be explained by the decrease in plants’ photosynthesis, whereas plants exposed to Cd toxicity had lower chlorophyll levels. At the anatomy level, high Cd concentrations resulted in anatomical abnormalities such as an unusual vascular system, abnormal lignification in the pith parenchyma, and enlarged cortical cells. Moreover, all Cd concentrations resulted in a highly significant decrease in stomatal area and stomatal density (the number of stomata per mm 2 ). In addition to growth inhibition, Cd-induced oxidative damage to pea plants as indicated by increased hydrogen peroxide (H 2 O 2 ) and Malondialdehyde (MDA) levels. To reduce stress toxicity, plants treated with Cd at 50 and 100 (mg/kg) showed a significant increase in antioxidant capacity. Peroxidase (POD) enzyme activity was significantly increased by 41.26%, 28.64%, 77.05%, and 60.77% in both seasons, respectively. Si at 300 ppm under Cd (100 mg/kg) stress conductions considerably reduced (MDA) contents by 29.02% and 29.12%, in the two seasons, respectively. The findings pointed out that Si’s ability to protect pea against the oxidative stress caused by Cd toxicity.
Journal Article
Mycorrhizal colonization and Streptomyces viridosporus HH1 synergistically up-regulate the polyphenol biosynthesis genes in wheat against stripe rust
by
Abdalla, Sara A.
,
Elazab, Nahla T.
,
El-Sharkawy, Hany H.
in
Acids
,
Agricultural research
,
Agriculture
2023
Background
Stripe rust is considered one of the most devastating diseases of wheat all over the world, resulting in a high loss in its production. In this study, time-course changes in expression of the polyphenol biosynthesis pathways genes in wheat against stripe rust were investigated. The defense mechanisms triggered by mycorrhizal colonization and/or spraying with
Streptomyces viridosporus
HH1 against this disease were also investigated.
Results
Results obtained revealed that
C3H
, which is considered the key gene in lignin biosynthesis, was the most expressed gene. Furthermore, most of the chlorogenic acid and flavonoid biosynthesis genes were also overexpressed. Volcano plots of the studied genes reveal that the dual treatment led to a high significant overexpression of 10 out of the 13 studied genes. Heatmap of these genes showed that the most frequent expressed gene in response to all applied treatments along the study period was
DFR
, the key gene in the biosynthesis of anthocyanidins. Gene co-expression network of the studied genes showed that
HQT
was the most central gene with respect to the other genes, followed by
AN2
and
DFR
, respectively. Accumulation of different flavonoids and phenolic acids were detected in response to the dual treatment, in particular, cinnamic acid, coumarin, and esculetin, which recorded the highest elevation level recording 1000, 488.23, and 329.5% respectively. Furthermore, results from the greenhouse experiment showed that application of the dual treatment led to an 82.8% reduction in the disease severity, compared with the control treatment.
Conclusions
We can conclude that the biosynthesis of lignin, chlorogenic acid, and flavonoids contributed to the synergistic triggering effect of the dual treatment on wheat resistance to stripe rust.
Journal Article
Foliar spray of silica improved water stress tolerance in rice (Oryza sativa L.) cultivars
by
El-Okkiah, Samira A. F.
,
Shehab Eldeen, Safaa A.
,
AbuQamar, Synan F.
in
Agricultural production
,
Agricultural research
,
Cereal crops
2022
Rice ( Oryza sativa L.) is a major cereal crop and a staple food across the world, mainly in developing countries. Drought is one of the most important limiting factors for rice production, which negatively affects food security worldwide. Silica enhances antioxidant activity and reduces oxidative damage in plants. The current study evaluated the efficiency of foliar spray of silica in alleviating water stress of three rice cultivars (Giza178, Sakha102, and Sakha107). The seedlings of the three cultivars were foliar sprayed with 200 or 400 mg l -1 silica under well-watered [80% water holding capacity (WHC)] and drought-stressed (40% WHC)] conditions for two summer seasons of 2019 and 2020. The obtained results demonstrated that drought stress caused significant decreases in growth, yield, and physiological parameters but increases in biochemical parameters (except proline) of leaves in all rice cultivars compared to well-irrigated plants (control). The roots of drought-stressed seedlings exhibited smaller diameters, fewer numbers, and narrower areas of xylem vessels compared to those well-watered. Regardless of its concentration, the application of silica was found to increase the contents of photosynthetic pigments and proline. Water relation also increased in seedlings of the three tested rice cultivars that were treated with silica in comparison to their corresponding control cultivars when no silica was sprayed. Foliar application of 400 mg l -1 silica improved the physiological and biochemical parameters and plant growth. Overall, foliar application of silica proved to be beneficial for mitigating drought stress in the tested rice cultivars, among which Giza178 was the most drought-tolerant cultivar. The integration of silica in breeding programs is recommended to improve the quality of yield and to provide drought-tolerant rice cultivars under drought-stress conditions.
Journal Article
Comparative analysis of salinity tolerance mechanisms in two maize genotypes: growth performance, ion regulation, and antioxidant responses
by
Ramadan, Ebrahim A.
,
Ueda, Akihiro
,
Assaha, Dekoum V. M.
in
Abiotic stress
,
Agricultural production
,
Agriculture
2024
This study investigates the differential responses of two maize genotypes, SC180 and SC168, to salt stress, aiming to elucidate the mechanisms underlying salinity tolerance and identify traits associated with improved stress resilience. Salinity stress, imposed by 150 mM NaCl, adversely affected various growth parameters in both genotypes. SC180 exhibited a more pronounced reduction in shoot length (13.6%) and root length (13.6%) compared to SC168, which showed minimal reductions (3.0% and 2.3%, respectively). Additionally, dry weight losses in SC180's leaves, stems, and roots were significantly greater than those in SC168. Under salinity stress, both genotypes accumulated Na
+
in all organs, with SC168 showing higher Na + concentrations. However, K
+
levels decreased more significantly in SC180's leaves than in SC168's. The study also assessed physiological responses, noting that SC180 experienced a substantial reduction in relative water content (RWC) in leaves (22.7%), while SC168's RWC remained relatively stable (5.15%). Proline accumulation, a marker for osmotic adjustment, increased 2.3-fold in SC168 compared onefold in SC180. Oxidative stress indicators, such as electrolyte leakage and hydrogen peroxide levels, were elevated in both genotypes under salt stress, with SC180 showing higher increases (48.5% and 48.7%, respectively) than SC168 (35.25% and 22.0%). Moreover, antioxidant enzymes (APX, CAT, POD, SOD, GR) activities were significantly enhanced in SC168 under salinity stress, whereas SC180 showed no significant changes in these activities. Stress indices, used to quantify and compare salinity tolerance, consistently ranked SC168 as more tolerant (average rank = 1.08) compared to SC180 (average rank = 1.92). Correlation analyses further confirmed that SC168's superior tolerance was associated with better Na + regulation, maintenance of K
+
levels, and a robust antioxidant defense system. In conclusion, SC168 demonstrated greater resilience to salinity stress, attributed to its efficient ion regulation, stable water status, enhanced osmotic adjustment, and strong antioxidant response. These findings provide valuable insights for breeding and developing salinity-tolerant maize varieties.
Journal Article
The effect of using fresh farmyard manure (animal manure) on the severity of Fusarium verticilioides in soil, root, stem, and kernels as well as lodging and borer incidence of maize plants
by
Seddek, Nermien H.
,
Abo-Elmagd, Heba I.
,
Oueslati, Moufida A.
in
Animal manures
,
Borers
,
Corn
2023
Fusarium verticillioides , an important maize pathogen, produce fumonisins, causes stalk rot and consequentially reduce crop growth and yield. Therefore, herein we aimed to evaluate the potential use of two farmyard soil organic manures, i.e., fresh (5-6 days old) and stored (5-6 months old) organic manure, to manage F. verticillioides infections as well as borer incidence and lodging in maize plants. After 30, 60, and 90 days of sowing, samples of soil, roots, and stems were collected to isolate F. verticillioides . Moreover, we estimated ear and kernel rot induced by F. verticillioides at the final harvest. Fresh organic manure treatment increased infection rates of F. verticillioides in soil, roots, stem and kernels compared to the control treatment. In contrast, stored organic manure plots treatments decrease F. verticillioides frequency. At 90 days after sowing, stored organic manure suppressed the survival of F. verticillioides , which reduced the F. verticillioides incidence percent. These results were similar to the effect of herbicides-and insecticide-treated plots demonstrated, which show a significant decrease in F. verticillioides incidence rates. Mycological analysis on symptomless kernels revealed a higher % of pathogen infection in opened husks variety (Balady) than closed husks variety (SC10). Compared with stored organic manure, the stem borer incidence and lodging percentage were the highest in fresh organic manure plots. Finally, these results demonstrated that storing organic manure within five to six months as farmyard manure led to high-temperature centigrade within organic manure, thereby destroying spores of F. verticillioides , whereas fresh organic manure did not.
Journal Article