Dr Suha Jabaji, PhD
Associate Dean - Research, Faculty of Agricultural & Environmental Sciences
suha [dot] jabaji [at] mcgill [dot] ca (E-mail)
The research program of Dr. Jabaji is targeted towards understanding the molecular mechanisms of mycoparasitism and induced resistance by non-pathogenic and symbiotic soil organisms. Her interests focus on molecular plant pathology, characterisation, expression and quantification of fungal genes that encode cell wall degrading enzymes, and genes involved in induced resistance. She is also interested in detection and quantification of soil-borne pathogens and biological control agents from biological and environmental samples using PCR techniques.
Role of cell wall degrading enzymes (CWDEs) in mycoparasitism
Several published work from our laboratory had shown that chitinases and glucanases, purified from the mycoparasite Stachybotrys elegans, are induced and activated in the presence of the soil-borne pathogen, Rhizoctonia solani. These CWDEs are released during the mycoparasitic process, and are antifungal causing lysis of hypal tips as early as one hour. We are in the process of cloning genes encoding some of these enzymes by using RACE-PCR technology. A sechi44 cDNA encoding an endochitinase from S. elegans has been cloned and characterized. The expression of sechi44 increases when the mycoparasite parasitizes its host, and is also expressed prior to contact suggesting that sechi44 could be induced by an elicitor or a signal molecule.
Role of beneficial organisms in elicitation of plant defense
We are interested in assessing the impact of beneficial fungi on the plant's defence responses during a pathogenic infection. To do so, we assess the plant's defence responses at several time points during initial stages of infection by the pathogen, and determine whether these responses are expressed in plant tissues other than the roots, and distant from the site of inoculation. The temporal and spatial accumulation of transcripts coding for PAL, CHS, CHI, Gluc in roots, stems and leaves of protected beans infected or not with R. solani is currently being quantified using real-time RT-PCR. We are also evaluating the bio-protective ability of these beneficial organisms in conferring resistance against other soil-borne pathogens.
Diagnostics of soil fungi using PCR technologies
We have projects aimed at designing and developing specific SCAR markers to be used in real-time PCR assays for the detection and quantification of soil fungi including pathogens and biological control agents (BCAs). So far, we have developed SCAR markers for some BCAs and have used them with success to detect target organisms in field soils.
Aliferis KA, Jabaji S. 2012. FT-ICR/MS and GC-EI/MS metabolomics networking unravels global potato sprout's responses to Rhizoctonia solani infection. PLoS One 7(8): e42576
Aliferis K, Copley TR,Jabaji S. 2012. Gas chromatography-mass spectrometry metabolite profiling of worker honeybee (Apis mellifera L.) hemolymph for the study of Nosema ceranae infection. Journal of Insect Physiology. DOI:10.1016/j.jinsphys.2012.07.010.9.
Copley TR, ChenH, Giovenazzo P, Houle E, Jabaji S. 2012. Prevalence and seasonality of Nosema Species in Quebec Forager Honeybees. The Canadian Entomologist. DOI: 10.4039/tce.2012.46.
Copley TR,Jabaji S. 2012. Honeybee glands as possible infection reservoirs of Nosema ceranae and N. apis in naturally infected forager bees. Journal of Applied Microbiology 112(1): 15-24.
Ngwa F, Madramootoo C, Jabaji S. 2012. Monitoring Toxigenic Microcystis strains in the Missisquoi Bay, Quebec, by PCR Targeting Multiple Toxic Gene Loci. Environmental Toxicology DOI:10.1002/tox.21770.
Aliferis KA, Jabaji S. 2011. Metabolomics-a robust bioanalytical approach for the discovery of the modes-of-action of pesticides: a review. Pesticides Biochemistry and Physiology 100(2) 105-117. (Number 1 hottest article of the year).
Aliferis KA, Jabaji S. 2012. Deciphering plant-pathogen interactions applying metabolomics: Principles and applications. Canadian Journal of Plant Pathology 34:29-33.
Chamoun, R, Jabaji S. 2011. Expression of genes of Rhizoctonia solani and the biocontrol Stachybotrys elegans during mycoparasitism of hyphae and sclerotia. Mycologia 103: 483-493.
Aliferis KA, Cubeta M, Jabaji S. 2011. Chemotaxonomy of fungi in the Rhizoctonia solani species complex using GC/MS metabolic profiling Metabolomics DOI:10.1007/s11306-011-0340-1.
Mimee, B, Avis TJ, S. Boivin, Jabaji S, R. Tweddell R. 2011. Effect of iron and nitrogen on the development of Helminthosporium solani and potato silver scurf. Canadian Journal of Plant Pathology 33: 506-511.
Chen H, S. Jabaji S, P. Seguin. 2011. Gene expression of isoflavones-related genes in soybean. Canadian Journal of Plant Science 91: 69-705.
Copley TR, Giovenazzo, P, Jabaji S. 2011. Honeybee bottom scraps and frass represent a potential source of Nosema apis and N. ceranae infections in naturally infected hives. Apidologie DOI: 10.1007/s13592-012-0147-8.
Jeannotte R, Hamel C, Jabaji S, Whalen JK. 2010. Pyrolysis-mass spectrometry and gas chromatography-flame ionization detection as complementary tools for soil lipid characterization. Journal of Analytical and Applied Pyrolysis 90: 232-237.
Aliferis KA, Jabaji S. 2010. Metabolite composition and bioactivity of Rhizoctonia solani sclerotial exudates. J. Agricultural and Food Chemistry. 58: 7604–7615.
Aliferis KA, Jabaji S. 2009. 1H NMR and GC-MS metabolic fingerprinting of sclerotia of the soilborne pathogen Rhizoctonia solani. 2010. Metabolomics 6:96-108.
Chen H, Seguin P, Jabaji S. Differential expression of genes encoding the phenylpropanoid pathway upon infection of soybean seedlings by Rhizoctonia solani. 2009. Canadian Journal of Plant Pathology 31: 356-367.
Abbasi PA,Jabaji S, LazarovitsG. 2009. Detection of high concentrations of organic acids in fish emulsions and their role in pathogens or disease suppression. Phytopathol. 99: 274-281.
Chen H, Constan L, Seguin P, Archambault A, Jabaji-Hare S. 2009. Gene Expression and Isoflavone Concentrations in Different Cultivars of Soybean Sprouts Treatedwith Chitosan. Crop Science 49: 224-236.
Morissette D, Dauch AL, Beech R, Masson L, Brousseau R, Jabaji-Hare S. 2008. Isolation of mycoparasitic-related transcripts by SSH during interaction of the mycoparasite Stachybotrys elegans with its host Rhizoctonia solani. Current Genetics 53: 67-80.