Publications by authors named "Yaser M Hafez"

NF-Y is a class of heterotrimeric transcription factor composed of three subunits; NF-YA, NF-YB, and NF-YC. This complex binds to the CCAAT box found in eukaryotic promoters and is involved in the plant development and proliferation at various stages. Although many studies were conducted on NF-Y gene family in various species, but no study has been reported yet in switchgrass (Panicum virgatum L.

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A highly efficient low-cost adsorbent was prepared using raw and chemically modified cellulose isolated from sugarcane bagasse for decontamination of Cr(VI) from wastewater. First, cellulose pulp was isolated from sugarcane bagasse by subjecting it to acid hydrolysis, alkaline hydrolysis and bleaching with sodium chlorate (NaClO). Then, the bleached cellulose pulp was chemically modified with acrylonitrile monomer in the presence Fenton's reagent (Fe/HO) to carry out grafting of acrylonitrile onto cellulose by atom transfer radical polymerization.

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Our earlier research showed that an interspecific tobacco hybrid ( 'Columbia' [NEC]) displays elevated levels of salicylic acid (SA) and enhanced resistance to localized necrotic symptoms (hypersensitive response [HR]) caused by tobacco mosaic virus (TMV) and tobacco necrosis virus (TNV), as compared with another interspecific hybrid ( [NE]) derived from the same parents. In the present study, we investigated whether symptomatic resistance in NEC is indeed associated with the inhibition of TMV and TNV and whether SA plays a role in this process. We demonstrated that enhanced viral resistance in NEC is manifested as both milder local necrotic (HR) symptoms and reduced levels of TMV and TNV.

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The effect of foliar treatment with jasmonic acid at 0.5 mM (JA) and biochar (15 ton ha) as a soil amendment for the faba bean (Vicia faba L. Sakha 4) was studied under salinity conditions.

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Drought stress deleteriously affects growth, development and productivity in plants. So, we examined the silicon effect (2 mmol) and proline (10 mmol) individually or the combination (Si + proline) in alleviating the harmful effect of drought on total phenolic compounds, reactive oxygen species (ROS), chlorophyll concentration and antioxidant enzymes as well as yield parameters of drought-stressed sugar beet plants during 2018/2019 and 2019/2020 seasons. Our findings indicated that the root diameter and length (cm), root and shoot fresh weights (g plant) as well as root and sugar yield significantly decreased in sugar beet plants under drought.

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Here we show that in tobacco ( cultivar Samsun NN ) the development of gene-mediated, symptomless, extreme resistance to (PVX) is preceded by an early, intensive accumulation of the reactive oxygen species (ROS) superoxide (O·), evident between 1 and 6 h after inoculation and associated with increased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activities. This suggests a direct contribution of this ROS to virus restriction during symptomless, extreme resistance. Superoxide inhibition in PVX-inoculated leaves by infiltration of antioxidants (superoxide dismutase [SOD] and catalase [CAT]) partially suppresses extreme resistance in parallel with the appearance of localized leaf necrosis resembling a hypersensitive resistance (HR) response.

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Broomrape parasitism on faba bean ( L.) is the most destructive factor for this crop in Egypt. Pot experiments were conducted during the two successive seasons 2017/2018 and 2018/2019 to study the mitigation of broomrape stress on faba bean using a ten-fold dilution of 10% (w/v) spent mushroom substrate extract (SMSE) of and the same dilution of culture filtrate of mushroom (MCF) grown in potato dextrose broth (PDB) at a rate of 48 l hectare compared with the commercial herbicide Roundup (Glyphosate 48% emulsifiable concentrate) at a rate of 144 cm ha on the two varieties (Misr3 and Sakha3) cultivated in broomrape-infested soil.

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Silicon is one of the most significant elements in plants under abiotic stress, so we investigated the role of silicon in alleviation of the detrimental effects of salinity at two concentrations (1500 and 3000 ppm sodium chloride) in sweet pepper plants in two seasons (2018 and 2019). Our results indicated that relative water content, concentrations of chlorophyll a and b, nitrogen, phosphorus and potassium contents, number of fruits plant, fruit fresh weight plant (g) and fruit yield (ton hectare) significantly decreased in salt-stressed sweet pepper plants as compared to control plants. In addition, electrolyte leakage, proline, lipid peroxidation, superoxide (O) and hydrogen peroxide (HO) levels, soluble sugars, sucrose, and starch content as well as sodium content significantly increased under salinity conditions.

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Generally, under normal conditions plants are resistant to many of the incompatible pathogens (viral, fungal and bacterial), and this is named "non-host resistance phenomenon". To understand this phenomenon, different types of food crops (faba bean, squash, barley and wheat) were inoculated with compatible and incompatible pathogens. Strong resistance symptoms were observed in the non-host/incompatible pathogen combinations as compared with host/compatible pathogen combinations, which showed severe infection (susceptibility).

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Chilling, a sort of cold stress, is a typical abiotic ecological stress that impacts the development as well as the growth of crops. The present study was carried to investigate the role of ascorbic acid root priming in enhancing tolerance of tomato seedlings against acute chilling stress. The treatments included untreated control, ascorbic acid-treated plants (AsA; 0.

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Brucellosis is one of the most economically significant infectious diseases in Egypt. The study aimed to assess the seroprevalence by indirect ELISA by examining serum samples from 720 cattle and 320 sheep and detection and characterization of Brucella spp. from 24 clinical samples (placenta) by bacterial culture (BC) and PCR targeting bcsp31 gene.

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Water deficit stress is an abiotic stress that causes reductions in growth and yield of many field crops around the world. The present research was aimed to elucidate the mitigating efficiency of exogenous application of select osmoregulators and biostimulants, i.e.

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Nonhost resistance is the most common form of disease resistance exhibited by plants against most pathogenic microorganisms. Type I nonhost resistance is symptomless (i.e.

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Pretreatment of tobacco leaves with low concentrations (5 to 10 mM) of H₂O₂ suppressed hypersensitive-type necrosis associated with resistance to Tobacco mosaic virus (TMV) or Pseudomonas syringae pv. phaseolicola. The same pretreatment resulted in suppression of normosensitive necrosis associated with susceptibility to Botrytis cinerea.

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