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"Omran, Ahmed"
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Evaluation of wheat (Triticum aestivum L.) salt stress tolerance using physiological parameters and retrotransposon-based markers
About 6% of the total land area in the world and 20% of the irrigated land is suffering from salt stress. Egypt is one of the countries that suffer from salt stress problems. The aim of this study was to determine salt stress tolerance of six wheat (
Triticum aestivum
L.) genotypes. These genotypes can be grown all over the world, found in gene banks and have pedigree. These genotypes were grown in pots under greenhouse conditions and subjected to two salt levels (tap water or control and 200 mM). Some morphological and physiological traits were determined. The results revealed that there were significant variations with all morphological and physiological traits as influenced by salt stress and genotypes. All studied morphological traits (shoot and root length and yield attributes) were decreased under salt stress conditions except Sids 13 and Sakha 94 genotypes which showed non-significant effect compared with unstressed plants. Total phenol, total flavonoid and antioxidant activity were significantly increased in shoots of all wheat genotypes under salt stress. Wheat genotypes responded differently to mineral contents under salt stress. The SDS-PAGE of seed proteins gave high level of genetic variability with polymorphism percentage of 65.38%. Furthermore, they revealed some important biochemical markers for salt stress tolerance. The six wheat genotypes were fingerprinted with eight primers using inter-primer binding sites and inter-retrotransposon amplified polymorphism techniques. In conclusion, the techniques marked each genotype successfully with different unique bands and detected molecular genetic markers correlated with salt tolerance in wheat crops.
Journal Article
Green synthesized silver nanoparticles mediated by Fusarium nygamai isolate AJTYC1: characterizations, antioxidant, antimicrobial, anticancer, and photocatalytic activities and cytogenetic effects
Green biosynthesized nanoparticles have a bright future because they can be produced using a method that is more energy-efficient, cost-effective, repeatable, and environmentally friendly than physical or chemical synthesis. In this study, silver nanoparticles (AgNPs) were produced using the
Fusarium nygamai
isolate AJTYC1. Several techniques were used to characterize the synthesized AgNPs, including UV–Vis spectroscopy, transmission electron microscope, zeta potential analysis, X-ray diffraction analysis, energy dispersive X-ray, and Fourier transform-infrared spectroscopy. AgNPs showed a distinctive surface plasmon resonance (SPR) peak in the UV–visible range at 310 nm. The morphology of the biosynthesized AgNPs was spherical, and the TEM image shows that they ranged in size from 27.3 to 53.1 nm. The notable peaks of the FT-IR results show the different groups for the alkane, alkynes, cyclic alkenes, carboxylic, aromatic amine, esters, and phenolics. Additionally, the results showed that AgNPs had superior antioxidant activity when compared to ascorbic acid and butylated hydroxytoluene, which is a powerful antioxidant. Additionally, AgNPs have antibacterial action utilizing agar diffusion against gram-positive bacteria, gram-negative bacteria, and antifungal activity. AgNPs’ anticancer activity varied depending on the type of cancer it was used to treat, including hepatocellular cancer (HepG2), colorectal carcinoma (HCT116), and breast cancer of the mammary gland (MCF7). The viability of the cancer cell lines was reduced with increasing AgNP concentration. AgNPs also demonstrated promising photocatalytic activity by reducing methylene blue, safranin, crystal violet, and green malachite by 88.3%, 81.5%, 76.4%, and 78.2%, respectively. In addition, AgNPs significantly affected the
Allium cepa
plant’s mitotic index and resulted in chromosomal abnormalities as compared to the control. Thus, the synthesized AgNPs demonstrated an efficient, eco-friendly, and sustainable method for decolorizing dyes as well as antioxidant, antibacterial, antifungal, and anticancer activities. This could be a huge victory in the fight against numerous dynamic diseases and lessen wastewater dye contamination.
Journal Article
Cytogenetic impact of gamma radiation and its effects on growth, yield and drought tolerance of maize (Zea mays L.)
Maize is the third most important grain crop worldwide after wheat and rice; it is a vital global crop, serving as a key source of food, animal feed, and industrial products, making it essential for food security and economic stability in many countries. Drought stress adversely affects water uptake and can stunt growth, reducing the overall productivity of maize. So, this study was carried out to investigate the cytogenetic effects of gamma radiation and drought stress on maize SC131 genotype, focusing on chromosomal aberrations in seedling root meristems induced by varying doses of gamma irradiation (50, 100, 150, 200, and 250 Gray) and drought stress imposed by 10% polyethylene glycol (PEG). The present study also aims to evaluate the impact of these treatments on growth parameters under a controlled pot experiment. Additionally, molecular polymorphism induced by both gamma irradiation and drought stress was analyzed using Real-Time quantitative PCR techniques for
DREB2
,
ERF
, and
EF
transcription factors. Also, under a field condition experiment, maize plants were subjected to the same gamma irradiation doses and drought stress by reducing the number of irrigations, with subsequent evaluations of yield attributes to assess the overall impact of treatments on plant performance. The study also investigates the sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) banding patterns of proteins in grains yielded under the influence of gamma radiation and drought treatments. Findings of the current investigation indicate that the low dose of gamma radiation (50 Gray) not only induces cytogenetic changes but also enhances drought tolerance and improves yield characteristics, suggesting that targeted gamma irradiation could serve as a viable strategy to bolster maize resilience in challenging environmental conditions.
Journal Article
Agro-morphological, biochemical, and molecular markers of barley genotypes grown under salinity stress conditions
The aim of this study was to evaluate the impact of salt stress on morphological, yield, biochemical, and molecular attributes of different barley genotypes. Ten genotypes were cultivated at Fayoum Research Station, El-Fayoum Governorate, Egypt, during two seasons (2020–2021 and 2021–2022), and they were exposed to two different salt concentrations (tap water as a control and 8000 ppm). The results showed that genotypes and salt stress had a significant impact on all morphological and physiological parameters. The morphological parameters (plant height) and yield attributes (spike length, number of grains per spike, and grain yield per plant) of all barley genotypes were significantly decreased under salt stress as compared to control plants. Under salt stress, the total soluble sugars, proline, total phenol, total flavonoid, ascorbic acid, malondialdehyde, hydrogen peroxide, and sodium contents of the shoots of all barley genotypes significantly increased while the potassium content decreased. L1, which is considered a sensitive genotype was more affected by salinity stress than the tolerance genotypes L4, L6, L9, and Giza 138. SDS-PAGE of seed proteins demonstrated high levels of genetic variety with a polymorphism rate of 42.11%. All genotypes evaluated revealed significant variations in the seed protein biochemical markers, with new protein bands appearing and other protein bands disappearing in the protein patterns of genotypes cultivated under various conditions. Two molecular marker techniques (SCoT and ISSR primers) were used in this study. Ten Start Codon Targeted (SCoT) primers exhibited a total of 94 fragments with sizes ranging from 1800 base pairs to 100 base pairs; 29 of them were monomorphic, and 65 bands, with a polymorphism of 62.18%, were polymorphic. These bands contained 21 unique bands (9 positive specific markers and 12 negative specific markers). A total of 54 amplified bands with molecular sizes ranging from 2200 to 200 bp were produced using seven Inter Simple Sequence Repeat (ISSR) primers; 31 of them were monomorphic bands and 23 polymorphic bands had a 40.9% polymorphism. The techniques identified molecular genetic markers associated with salt tolerance in barley crop and successfully marked each genotype with distinct bands. The ten genotypes were sorted into two main groups by the unweighted pair group method of arithmetic averages (UPGMA) cluster analysis based on molecular markers and data at a genetic similarity coefficient level of 0.71.
Journal Article
Molecular and biochemical characterization of wheat resistance to yellow rust (Puccinia striiformis f. Sp. tritici) using SSR markers and antioxidant profiles
Background
One of the most damaging foliar diseases of wheat in Egypt and around the world is yellow rust, often known as stripe rust, which is caused by
Puccinia striiformis
f. sp.
tritici
. This study aims to identify wheat cultivars resistant to yellow rust and to detect molecular markers linked to resistance. Two Egyptian bread wheat cultivars,
Yr10
and
Yr18
(highly resistant), and Gemmiza 11 and Shandweel 1 (susceptible), were evaluated. Four crosses and subsequent backcrosses between resistant and susceptible bread wheat genotypes were obtained. The phenolic content and antioxidant activity of the cultivars and their crosses under disease conditions were also measured for potential use in wheat breeding programs.
Results
The results showed that Gemmiza 11 and Shandweel 1 were highly susceptible and susceptible wheat cultivars, respectively. On the other hand, the two Yr monogenic lines (
Yr10
and
Yr18
) showed high resistance against stripe rust. In addition, the cross between the susceptible cultivars and the resistant monogenic lines exhibited immunity and high resistance to
Puccinia striiformis
(
Pst
). The highest phenolic and flavonoid contents were recorded in the immune cultivars. In addition, all immune wheat cultivars exhibited higher levels of superoxide anion radical, hydroxyl radical, and nitric oxide radical scavenging activity. Out of thirteen SSR markers tested, seven were found to be associated with resistance to yellow rust.
Conclusion
These markers may serve as the basis for marker-assisted selection programs aimed at enhancing wheat resistance to yellow rust.
Journal Article
Quantum phases of matter on a 256-atom programmable quantum simulator
Motivated by far-reaching applications ranging from quantum simulations of complex processes in physics and chemistry to quantum information processing
1
, a broad effort is currently underway to build large-scale programmable quantum systems. Such systems provide insights into strongly correlated quantum matter
2
–
6
, while at the same time enabling new methods for computation
7
–
10
and metrology
11
. Here we demonstrate a programmable quantum simulator based on deterministically prepared two-dimensional arrays of neutral atoms, featuring strong interactions controlled by coherent atomic excitation into Rydberg states
12
. Using this approach, we realize a quantum spin model with tunable interactions for system sizes ranging from 64 to 256 qubits. We benchmark the system by characterizing high-fidelity antiferromagnetically ordered states and demonstrating quantum critical dynamics consistent with an Ising quantum phase transition in (2 + 1) dimensions
13
. We then create and study several new quantum phases that arise from the interplay between interactions and coherent laser excitation
14
, experimentally map the phase diagram and investigate the role of quantum fluctuations. Offering a new lens into the study of complex quantum matter, these observations pave the way for investigations of exotic quantum phases, non-equilibrium entanglement dynamics and hardware-efficient realization of quantum algorithms.
A programmable quantum simulator with 256 qubits is created using neutral atoms in two-dimensional optical tweezer arrays, demonstrating a quantum phase transition and revealing new quantum phases of matter.
Journal Article
Quantum Kibble–Zurek mechanism and critical dynamics on a programmable Rydberg simulator
Quantum phase transitions (QPTs) involve transformations between different states of matter that are driven by quantum fluctuations
1
. These fluctuations play a dominant part in the quantum critical region surrounding the transition point, where the dynamics is governed by the universal properties associated with the QPT. Although time-dependent phenomena associated with classical, thermally driven phase transitions have been extensively studied in systems ranging from the early Universe to Bose–Einstein condensates
2
–
5
, understanding critical real-time dynamics in isolated, non-equilibrium quantum systems remains a challenge
6
. Here we use a Rydberg atom quantum simulator with programmable interactions to study the quantum critical dynamics associated with several distinct QPTs. By studying the growth of spatial correlations when crossing the QPT, we experimentally verify the quantum Kibble–Zurek mechanism (QKZM)
7
–
9
for an Ising-type QPT, explore scaling universality and observe corrections beyond QKZM predictions. This approach is subsequently used to measure the critical exponents associated with chiral clock models
10
,
11
, providing new insights into exotic systems that were not previously understood and opening the door to precision studies of critical phenomena, simulations of lattice gauge theories
12
,
13
and applications to quantum optimization
14
,
15
.
A Rydberg atom quantum simulator with programmable interactions is used to experimentally verify the quantum Kibble–Zurek mechanism through the growth of spatial correlations during quantum phase transitions.
Journal Article
Spin- and density-resolved microscopy of antiferromagnetic correlations in Fermi-Hubbard chains
The repulsive Hubbard Hamiltonian is one of the foundational models describing strongly correlated electrons and is believed to capture essential aspects of high-temperature superconductivity. Ultracold fermions in optical lattices allow for the simulation of the Hubbard Hamiltonian with control over kinetic energy, interactions, and doping. A great challenge is to reach the required low entropy and to observe antiferromagnetic spin correlations beyond nearest neighbors, for which quantum gas microscopes are ideal. Here, we report on the direct, single-site resolved detection of antiferromagnetic correlations extending up to three sites in spin-1/2 Hubbard chains, which requires entropies per particle well below s* = In(2).The simultaneous detection of spin and density opens the route toward the study of the interplay between magnetic ordering and doping in various dimensions.
Journal Article
Investigation of genetic diversity using molecular and biochemical markers associated with powdery mildew resistance in different flax (Linum usitatissimum L.) genotypes
Under greenhouse conditions, the resistance of 18 different genotypes of flax to powdery mildew was evaluated. To investigate genetic diversity and identify the molecular and biochemical markers linked to powdery mildew resistance in the tested genotypes, two molecular marker systems—start codon targeted (SCoT) and inter-simple sequence repeat (ISSR)—as well as a biochemical marker (protein profiles, antioxidant enzyme activity, and secondary metabolites) were used. Based on the results, the genotypes were classified into four categories: highly susceptible, susceptible, moderately susceptible, and moderately resistant. The genotypes differed significantly in powdery mildew severity: Polk had a severity of 92.03% and Leona had a severity of 18.10%. Compared to the other genotypes, the moderately resistant genotypes had higher levels of flavonoids, antioxidant enzymes, phenolics, and straw yield; nevertheless, their hydrogen peroxide and malondialdehyde levels were lower. Protein profiles revealed 93.75% polymorphism, although the ISSR marker displayed more polymorphism (78.4%) than the SCoT marker (59.7%). Specific molecular and biochemical markers associated with powdery mildew resistance were identified. The 18 genotypes of flax were divided into two major clusters by the dendrogram based on the combined data of molecular markers. The first main cluster included Leona (genotype number 7), considered moderate resistance to powdery mildew and a separate phenetic line. The second main cluster included the other 17 genotypes, which are grouped together in a sub-cluster. This means that, besides SCoT, ISSR markers can be a useful supplementary technique for molecular flax characterization and for identifying genetic associations between flax genotypes under powdery mildew infection.
Journal Article