9 results on '"Abdelbasset El Hadrami"'
Search Results
2. Combining Streptomyces hygroscopicus and phosphite boosts soybean’s defense responses to Phytophthora sojae
- Author
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Lorne R. Adam, Arbia Arfaoui, Abdelbasset El Hadrami, and Fouad Daayf
- Subjects
food.ingredient ,biology ,Inoculation ,Zoospore ,fungi ,food and beverages ,biology.organism_classification ,Horticulture ,food ,Animal ecology ,Seedling ,Insect Science ,Agar ,Phytophthora sojae ,Streptomyces hygroscopicus ,Agronomy and Crop Science ,Pathogen - Abstract
To determine the beneficial effect of the combination of phosphite (Phi) and Streptomyces hygroscopicus (S11) on soybean plants infected by Phytophthora sojae, soybean seeds were pre-treated with a suspension of S11, the leaves were sprayed with Phi and the roots were subsequently inoculated with P. sojae zoospores. Seedling growth and colonization of root tissue by the pathogen were monitored and the Phi concentration in the roots was quantified. Finally, the effect of S11 and/or Phi on defense responses and SA and JA production were recorded. Both S11 and Phi inhibited the growth of P. sojae in dual V8 agar cultures, and soybean pre-treatment with S11 and/or Phi reduced further infection in planta. In response to P. sojae, defense genes were upregulated in both tolerant and susceptible soybean varieties, especially in the latter. SA and JA accumulated more in the susceptible variety in response to P. sojae, and the use of S11 and/or Phi prior to inoculation induced a decrease in their production. SA accumulated earlier than JA in soybean roots in response to P. sojae in the tolerant variety, whereas JA accumulated earlier than SA in the susceptible one. As such, S11 combined with Phi significantly reduced P. sojae infection in soybean by delaying and reducing the activation of stress hormones and defense-related genes, offering an efficient mean to manage soybean’s infection by P. sojae.
- Published
- 2020
3. Induction of putative pathogenicity-related genes in Verticillium dahliae in response to elicitation with potato root extracts
- Author
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Lorne R. Adam, Maria Antonia Henriquez, Ahmed F. El-Bebany, Fouad Daayf, Abdelbasset El Hadrami, and Mohamed Badawi
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biology ,food and beverages ,Plant Science ,Fungi imperfecti ,biology.organism_classification ,Microbiology ,Pathosystem ,Suppression subtractive hybridization ,Complementary DNA ,Amplified fragment length polymorphism ,Verticillium dahliae ,Verticillium wilt ,Agronomy and Crop Science ,Gene ,Ecology, Evolution, Behavior and Systematics - Abstract
Verticillium dahliae is the main pathogen causing Verticillium wilt in potato. Management of this vascular disease is very challenging due to the soilborne nature of the pathogen. A better understanding of the molecular host–pathogen interactions is important for the development of novel strategies to control Verticillium wilt. In this pathosystem, the disease cycle starts with stimulation and germination of the V. dahliae microsclerotia through host root exudates. The present study reports on the use of potato root extracts derived from a susceptible (Kennebec) and a moderately resistant (Ranger Russet) cultivar to elicit pathogenicity-related genes in highly and weakly aggressive isolates of V. dahliae. Using a combined approach of subtractive hybridization and cDNA-AFLP, 573 transcripts differentially accumulated in one or the other isolate in response to root extracts were detected. Sixteen primer combinations representing EcoRI/MseI AFLP primers + A, T, C, or G were used to provide a complete coverage of the subtractive hybridization products. The detected differentially expressed transcripts in the highly and weakly aggressive isolates were 301 and 272, respectively. Among the amplified transcripts, 185 were recovered from the PAGE gel then re-amplified by PCR and further sequenced. BLAST search against the NCBI, the Broad Institute V. dahliae genome, and V. dahliae ESTs collection COGEME databases showed that some of the differentially expressed transcripts matched with known sequences, with assigned functions in V. dahliae such as polygalacturonases or with conserved hypothetical proteins. The remaining sequences had no match in these databases. The results are discussed based on the potential involvement of these genes in V. dahliae's pathogenesis.
- Published
- 2011
4. Induction of defense genes and secondary metabolites in saskatoons (Amelanchier alnifolia Nutt.) in response to Entomosporium mespili using jasmonic acid and Canada milkvetch extracts
- Author
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Maria Antonia Henriquez, Fouad Daayf, Abdelbasset El Hadrami, Erika Alejandra Wolski, Lorne R. Adam, Adriana Balbina Andreu, and Mohamed Badawi
- Subjects
Otras Biotecnología Agropecuaria ,Amelanchier alnifolia ,PR-5 ,Biotecnología Agropecuaria ,PR-2 ,RT-PCR ,Plant Science ,Biology ,Antioxidants ,chemistry.chemical_compound ,food ,Botany ,PR-1 ,Ecology, Evolution, Behavior and Systematics ,Flavonoids ,Entomosporium mespili ,Jasmonic acid ,jasmonic acid ,LOX ,SaskatoonsEntomosporium mespili ,food.food ,chemistry ,CIENCIAS AGRÍCOLAS ,Biological control ,Botánica ,PAL ,defense related-genes ,Phenolics ,HPLC ,Canada milkvetch extract ,Agronomy and Crop Science - Abstract
Entomosporium leaf and berry spot represent the most important disease of saskatoons (Amelanchier alnifolia Nutt.). This disease, caused by the ascomycete Entomosporium mespili (D.C.) Sacc., is difficult to control via conventional methods and no known saskatoon cultivar carries resistance to this pathogen. The aim of the present study was to enhance existing and induced defense responses of saskatoons using two host defense inducers, namely jasmonic acid and an extract from Canada milkvetch on two saskatoon cultivars, Smoky and Martin. Both inducers exhibited an ability to differentially induce the synthesis/accumulation of defense-related genes including those encoding for PR-1, PR-2, PR-5, LOX and PAL. Pre-treatment of saskatoon leaves with these inducers reduced the disease levels especially when applied to the moderately susceptible cultivar Martin. An accumulation of various hydroxycinnamic acid and proanthocyanidin derivatives also correlated with the disease levels recorded on both cultivars. Results are discussed on the basis of the induced pathways in an attempt to lay the ground for a better understanding of this hostpathogen interaction. In the meantime,wehave shown that the use of defense enhancers may be useful in integrated management strategies to control entomosporium leaf and berry spot in saskatoons spot in saskatoons. Fil: Wolski, Erika Alejandra. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata; Argentina Fil: Henriquez, Maria A.. University Of Manitoba; Canadá Fil: Adam, Lorne R.. University Of Manitoba; Canadá Fil: Badawi, Mohamed. University Of Manitoba; Canadá Fil: Andreu, Adriana Balbina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Biológicas; Argentina. Universidad Nacional de Mar del Plata; Argentina Fil: Hadrami, Abdelbasset El . University Of Manitoba; Canadá Fil: Daayf, Fouad. University Of Manitoba; Canadá
- Published
- 2010
5. Priming canola resistance to blackleg with weakly aggressive isolates leads to an activation of hydroxycinnamates
- Author
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Abdelbasset El Hadrami and Fouad Daayf
- Subjects
food.ingredient ,biology ,Host (biology) ,fungi ,Blackleg ,Brassica ,food and beverages ,Plant Science ,biology.organism_classification ,Leptosphaeria ,Horticulture ,food ,Leptosphaeria maculans ,Botany ,Phoma ,Leaf spot ,Canola ,Agronomy and Crop Science - Abstract
Blackleg (Phoma leaf spot), caused by the ascomycete Leptosphaeria spp. (anamorph: Phoma lingam), is a serious yield-limiting factor in canola. Leptosphaeria spp. populations are highly diverse and display differential interactions with canola cultivars, ranging from hypersensitive-like reactions to partial resistance and susceptibility. Leptosphaeria biglobosa encompasses weakly aggressive isolates and can be found late in the season towards maturity stages of the crop while other isolates from Leptosphaeria maculans are highly aggressive and can be detected throughout the season. In an earlier study, we showed the primary involvement of lignin in the containment of the progress of Phoma leaf spot symptoms around the infection sites by comparing the reaction of three different cultivars with a set of isolates with various levels of aggressiveness. The present investigation reports on further characterization of the host responses to L. biglobosa and L. maculans isolates used individually or subsequently ...
- Published
- 2009
6. Variations in relative humidity modulate Leptosphaeria spp. pathogenicity and interfere with canola mechanisms of defence
- Author
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Abdelbasset El Hadrami, W. G. Dilantha Fernando, and Fouad Daayf
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Canker ,education.field_of_study ,food.ingredient ,biology ,Population ,Blackleg ,Brassica ,food and beverages ,Plant Science ,Horticulture ,biology.organism_classification ,medicine.disease ,Leptosphaeria ,food ,Leptosphaeria maculans ,Agronomy ,medicine ,Phoma ,education ,Canola ,Agronomy and Crop Science - Abstract
Blackleg (phoma stem canker), caused by Leptosphaeria spp., is an important disease of canola (oilseed rape, Brassica napus). Control strategies rely on the use of resistant cultivars, chemical and disease-reducing cropping practices. In Canada, the pathogen population is represented by L. maculans and L. biglobosa, which are considered to be highly and weakly aggressive, respectively. It is largely admitted that L. biglobosa isolates are not able to cause a significant amount of stem canker and develop on the plant only when it becomes senescent, late in the season. The prevalence of L. maculans over L. biglobosa has been considered to be linked to the low aggressiveness of the latter. However, in this study, we show that L. biglobosa isolates could become highly aggressive in terms of lesion appearance on cotyledons, if the right conditions of temperature and relative humidity (RH) are provided. Percent germination of inoculated pycnidiospores was not affected by the RH regimes tested. This is the first study to show the importance of RH as a factor conditioning the pathogenicity of L. biglobosa isolates on canola cotyledons. Concurrent changes in the host defence mechanisms against L. biglobosa isolates in response to variations in the RH were also investigated. Under high RH, the increase in disease caused by the weakly aggressive isolates coincided with a reduced accumulation of lignin at the early stages of infection.
- Published
- 2009
7. Biological control of bayoud disease in date palm: Selection of microorganisms inhibiting the causal agent and inducing defense reactions
- Author
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Mohamed Chérif, Fouad Daayf, Ismaïl El Hadrami, Abdelbasset El Hadrami, Majida El Hassni, and Essaid Ait Barka
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chemistry.chemical_classification ,biology ,Phytoalexin ,Pseudomonas ,food and beverages ,Plant Science ,Fungi imperfecti ,biology.organism_classification ,Microbiology ,chemistry ,Cereus ,Fusarium oxysporum ,Ulocladium atrum ,Rahnella aquatilis ,Agronomy and Crop Science ,Ecology, Evolution, Behavior and Systematics ,Mycelium - Abstract
Twenty-one isolates of microorganisms, including Bacillus spp., Rhizobium spp., Ulocladium atrum, Candida guilliermondii, Pseudomonas sp., Rahnella aquatilis and other bacteria not yet identified, were tested to determine their effects on the mycelial growth and the sporulation of Fusarium oxysporum f.sp. albedinis (Foa), the causal agent of bayoud on date palm. The potential of these antagonists in the induction of defense reactions in date palm seedlings was also studied. Four bacteria, B. pumilus W1, R. aquatilis W2, B. cereus X16 and n.d. S1, have exhibited a high inhibition toward mycelial growth of Foa (70–77%), and its sporulation (80–95% of the control). Moreover, cytological alterations have been detected in the Foa mycelium grown in the inhibition zone. Application of these antagonists into date palm seedlings has led to trigger defense reactions with an accumulation of non-constitutive hydroxycinnamic acid derivatives, such as the sinapic derivative I2, known to play a crucial role in resistance of date palm to Foa. This reaction was more pronounced in resistant cultivar (BSTN) than in susceptible (JHL). The combined effects of direct and indirect actions of Foa antagonists are discussed in the hope of providing a biocontrol strategy against bayoud.
- Published
- 2007
8. Local and distal gene expression of pr-1 and pr-5 in potato leaves inoculated with isolates from the old (US-1) and the new (US-8) genotypes of Phytophthora infestans (Mont.) de Bary
- Author
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Abdelbasset El Hadrami, Lorne R. Adam, Fouad Daayf, and Xiben Wang
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biology ,Inoculation ,food and beverages ,Plant Science ,biology.organism_classification ,Microbiology ,Gene expression ,Phytophthora infestans ,Botany ,Genotype ,Blight ,Agronomy and Crop Science ,Gene ,Ecology, Evolution, Behavior and Systematics ,Solanaceae ,Pathogenesis-related protein - Abstract
The time-course and the spatial accumulation of PR-proteins pr-1 and pr-5 gene transcripts were investigated in two potato cultivars differing in their levels of susceptibility to late blight, caused by Phytophthora infestans (Mont.) de Bary. Cultivars Russet Burbank (RB, susceptible) and Kennebec (KB, moderately tolerant) were inoculated with either P. infestans genotype US-1 (old lineage) or US-8 (new lineage). A strong induction of both genes was detected in both cultivars inoculated with either P. infestans genotype, as compared to the healthy-controls. The accumulation of transcripts from both genes occurred earlier in KB than in RB leaflets. By comparing the two P. infestans isolates tested, a stronger and earlier induction of both PR genes was recorded in response to US-1 as compared to US-8. The spatio-temporal profiling of pr-1 and pr-5 genes expression showed a strong and early accumulation of transcripts at the local infection site, a late and intermediate level of induction at the proximal site, and no or very weak induction at a distal site remote from the infection site. These results show that pr-1 and pr-5 genes both are related to the defense mechanisms of potato to late blight, and that the higher infection success of P. infestans US-8 as compared to US-1 might be due to the late and/or the weak induction of these defense genes.
- Published
- 2006
9. Potato Early Dying and Yield Responses to Compost, Green Manures, Seed Meal and Chemical Treatments
- Author
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Oscar I. Molina, Mario Tenuta, Curtis Cavers, Fouad Daayf, Katherine Buckley, and Abdelbasset El Hadrami
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Compost ,fungi ,food and beverages ,Plant Science ,Biology ,engineering.material ,biology.organism_classification ,Verticillium ,Manure ,complex mixtures ,Crop ,Green manure ,Propagule ,Agronomy ,engineering ,Verticillium dahliae ,Agronomy and Crop Science ,White mustard - Abstract
Verticillium dahliae Kleb. is a soilborne fungal pathogen of many crops. In potato, it is the major causal agent of Early Dying. In Manitoba, potato fields planted with cv. Russet Burbank are infested with highly pathogenic V. dahliae isolates, which can produce up to 90 % disease severity. The objective of the study was to evaluate selected compost, green manure, and seed-meal treatments, in comparison with the soil fumigant Vapam, for their ability to reduce propagule density of V. dahliae in soil and decrease disease, and to enhance potato yield. Select green manure crops (oriental and white mustard, Canada milk vetch, sorghum-sudangrass, rye, alfalfa, oat/pea mixture), organic amendments (composted cattle manure and mustard seed-meal), and Vapam, and crop sequences that contribute to the suppression of Verticillium, or the improvement of potato yield were used in a 3-year field study initiated in 2006. Survival in soil of microsclerotia was evaluated as a measure of treatments’ success in potentially reducing Early Dying. Compost and seed-meal treatments, compared to an untreated control, reduced incidence to 30 and 40 %, respectively, but only seed-meal reduced V. dahliae propagule density. Overall, green manures over 1 or 2-years were ineffective in reducing propagule density or improving potato yield. Vapam was partially effective in reducing the propagule density only at the beginning of the potato season, but it did not reduce disease incidence compared to the control. Compost and seed-meal are promising as alternative control of V. dahliae. Only compost reduced disease and increased potato yield, which was associated with improved nutrient availability (phosphorus and sulfate) in soil.
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