BSc, MSc (Bangalore)
Ajjamada C. Kushalappa obtained his Ph. D. from University of Florida (USA), M.Sc (Plant Pathology) and B. Sc. (Agri) from University of Agricultural Sciences (Bengaluru, India). From 1977-1985 he was a Professor Titular Visitante, at Universidade Federal de Vicosa (Brazil). In 1985 he joined McGill University as an Assistant Professor in the Department of Plant Science, and in 1991 he became an Associate Professor. He is a recipient of CPS sponsored Dr. and Mrs D. L. Bailey award for an exception and distinguished contribution to plant pathology. He was an invited speaker on ‘Plant biotic stress resistance genes and genome editing’ at 16 national and international conferences in the past six years.
As a Plant Pathologist, Dr. Kushalappa 's current research focus is the identification plant biotic stress resistance genes through forward and reverse genetics (systems biology), and the use these genes to replace the susceptible genes in commercial cultivars, based on cisgenetic engineering (gene transfer between sexually compatible plants), using CRISPR-Cas9 systems, to increase the genetic diversity of crop plants.
Awards and Recognitions
1990: Dr. and Mrs. DL Bailey Award, for an exceptional and distinguished contribution to plant pathology
Member of the Natural Sciences and Engineering Research Council of Canada funding panel.
Associate editor of BMC Plant Biology.
Canada grows hundreds of cultivars for each crop. They are mainly bred for yield and thus have poor disease resistance. The fusarium head blight of wheat and barley not only causes heavy loss in yield but also produces mycotoxins in grains, which causes vomiting and hemorrhage in animals and humans. Late blight and scab are serious diseases of potato, the former requires weekly applications of fungicides to reduce loss. We are developing cisgenic cultivars (gene transfer from sexually compatible plants) to increase resistance to fusarium head blight in wheat and barley, and to late blight and scab in potato. Each cisgenic cultivar we produce can increase 10% increase in yield, in addition to reducing production costs and environmental impacts, amounting to millions of dollars income to Canada per year.
Dr. Kushalappa is a Plant Pathologist. His current research focus is to identify plant biotic stress resistance genes through forward and reverse genetics (systems biology), and use these genes to replace the susceptible genes in commercial cultivars, based on cis gene stacking (gene transfer between sexually compatible plants), using CRISPR-Cas9 systems, to increase the genetic diversity of crop plants.
Plants defend against pathogen attack using metabolites and proteins that are constitutively produced or induced following pathogen invasion. Based on metabolomics and proteomics, using liquid chromatography and high resolution mass spectrometry (LC-ESI-LTQ-Orbitrap), we have detected thousands of metabolites and proteins in wheat/barley – Fusarium graminearum (fusarium head blight) and potato-Phytophthora infestans (late blight) interaction systems. The resistance related (RR) metabolites were linked in their metabolic pathways to explore their precursors and possible polymers and plant structural components that explained the mechanisms of resistance. Several of these metabolites are known phytoalexins, toxin inhibitors, and cell wall reinforcing compounds. The proteins identified were mainly regulatory and catalytic enzymes that biosynthesize these metabolites. The metabolites with high fold change in abundance in resistant genotypes than in susceptible (RR metabolites) were searched in metabolomics network and genomic databases to identify candidate genes. Resistance gene regulation by receptors, phytohormones, MAP kinases and transcription factors also have been identified based on RNA sequencing combined with metabolomics. The putative resistance genes were sequenced in both resistant genotypes and commercial cultivars to identify polymorphisms. The candidate genes were then silenced (VIGS) in resistant genotypes to validate gene functions. The biotic stress resistance is due to hierarchies of genes, regulatory and RR metabolite and protein biosynthetic genes, which eventually produce phytoalexins and cell wall reinforcing metabolites and proteins to resist the pathogen. The non-functional or mutated genes in commercial cultivars are being replaced with resistance R genes to improve resistance against biotic stress. The cisgenic commercial cultivars developed with high biotic stress resistance should not only increase income but also reduce environment impacts, through reduced application of fungicides.
Current Graduate Students and Visiting Scientists
Mr. Shivappa Hukkeri (PhD): Wheat QTL-Fhb5 sequencing and metabolo-genomics to identify candidate genes against FHB.
Mr. Shailesh Karre (PhD): RNA sequencing and metabolomics of barley genotypes to identify candidate genes against FHB.
Mr. Udaykumar Kage (PhD): Metabolo-genomics of wheat NILs with QTL-2DL to identify resistance genes against FHB.
Mr. Dhananjay Dhokane (PhD): RNA sequencing and metabolomics of wheat QTL-Fhb2 to identify resistance R genes against FHB.
Miss Nancy Soni (PhD): Wheat QTL-Fhb1 sequencing and metabolo-genomics to identify resistance R genes against FHB.
Mr. Sripad Joshi (PhD): RNA sequencing and metabolomics of potato to identify resistance genes against late blight and development of a cisgenic cultivar, using CRISPR-Cas9.
Mr. Russiachand Singh (PhD): RNA sequencing and metabolomics of wheat cultivars to identify resistance genes against FHB and development of a cisgenic wheat cultivar.
Mr. Niranjan Hegde (PhD): Validation of resistance functions of candidate genes in potato genotypes against late blight and development of cisgenic Russet Burbank cultivar.
Dr. Huali Xue (VS): Development of cisgenic potato cultivar, through genome editing, for resistance to late blight.
Miss Fatemeh Kalantari (MS): Development of cisgenic wheat cultivar to increase bioavailability of minerals, using CRISPR-Cas9.
Karre S, Kumar A, Dhokane D, Kushalappa AC. 2016. Metabolo-transcriptome profiling of barley reveals induction of a chitin elicitor receptor kinase gene (HvCERK1) conferring resistance against Fusarium graminearum. Plant Molecular Biol. (Accepted).
Dhokane D, Karre S, Kushalappa AC, McCartney C. 2016. Integrated Metabolo-transcriptomics reveals fusarium head blight resistance genes in wheat QTL-Fhb2. PLoS ONE 11(5): e0155851; doi:10.1371/journal.pone.0155851.
Yogendra KN and Kushalappa AC. 2016. Integrated transcriptomics and metabolomics reveal induction of hierarchies of resistance genes in potato against late blight. Functional Plant Biology http://dx.doi.org/10.1071/FP16028.
Kumar A, Yogendra KN, Karre S, Kushalappa AC, Dion Y, Choo TM. 2016. WAX INDUCER1 (HvWIN1) transcription factor regulates free fatty acid biosynthetic genes to enforce cuticle to resist fusarium head blight in barley spikelets. J. Expt. Bot. DOI:10.1093/jxb/erw187.
Kushalappa AC, *Yogendra KN, *Karee S. 2016. Plant innate immune response: qualitative and quantitative resistance. Invited Review: Critical Rev. in Plant Science 35:38–55. http://dx.doi.org/10.1080/07352689.2016.1148980
Ji L, Yogendra KN, Mosa K, Kushalappa AC, Pineros C, Mosquera T and Narvaez C. 2016. Hydroxycinnamic acid functional ingredients and their biosynthetic genes in tubers of Solanum tuberosum Group Phureja. Cogent Food & Agriculture. 10.1080/23311932.201 (2: 1138595)
Yogendra KL, Kumar A, Sarkar K, Li y, Pushpa D, Mosa K, Duggavathi R and Kushalappa A. (2015). Transcription factor StWRKY1 regulates phenylpropanoid metabolites conferring late blight resistance in potato. The Journal of Experimental Botany DOI: 10.1093/jxb/erv434. 10.1093/jxb/erv434
Kage U, Kumar A, Dhokane D, Karre S, Kushalappa AC. (2015). Functional Molecular Markers for Crop Improvement. Critical Reviews in Biotechnology DOI: 10.3109/07388551.2015.1062743
Kumar A, Karre S, Dhokane D, Kage U, Hukkeri S, Kushalappa AC.(2015). Real-time quantitative PCR based method for the quantification of fungal biomass to discriminate quantitative resistance in barley and wheat genotypes to fusarium head blight. Journal of Cereal Science 64: 16-22. 64: 16-22.
Gunnaiah R, Kushalappa AC. 2014. Metabolomics deciphers the host resistance mechanisms in wheat cultivar Sumai-3, against trichothecene producing and non-producing isolates of Fusarium graminearum. Plant Physiol Biochem. 83:40-50.
Yogendra KN, Pushpa D, Mosa K, Kushalappa AC, Murphy A and Mosquera T. 2014. Quantitative resistance in potato leaves to late blight associated with induced hydroxycinnamic acid amides. Functional and Integrative Genomics. 14:285–298.
Pushpa D, Yogendra K, Gunnaiah R, Kushalappa AC and Murphy A. 2014. Identification of late blight resistance related metabolites and genes in potato through non-targeted metabolomics. Plant Molecular Biology Reporter. 32:584-595.
Chamarthi S, Kundan K, Gunnaiah R, Kushalappa AC, Dion Y, Choo TM. 2014. Identification of fusarium head blight resistance related metabolites specific to doubled-haploid lines in barley. European J. Plant Pathology. 138: 67-78.
Kushalappa AC and Gunnaiah R. 2013. Metabolo-proteomics to discover plant biotic stress resistance genes. INVITED REVIEW: Trends in Plant Science. 18: 522-531.
Gunnaiah R, Kushalappa AC, Duggavathi R, Fox S and Somers DJ. 2012. Integrated Metabolo-proteomic approach to decipher the mechanisms by which wheat QTL (Fhb1) contributes to resistance against Fusarium graminearum. PLoS ONE 7:e40695.
Kumaraswamy GK, Kushalappa AC, Choo TM, Dion Y. and Rioux S. 2012. Differential metabolic response of barley genotypes, varying in resistance, to trichothecene-producing and nonproducing (tri5-) isolates of Fusarium graminearum. Plant Pathology 61, 509–521.
Bollina V, and Kushalappa AC. 2011. In vitro inhibition of trichothecene biosynthesis in Fusarium graminearum by resistance-related endogenous metabolites identified in barley. Mycology 2:291-296.
Bollina V, Kushalappa AC, Choo TM, Dion Y and Rioux S. 2011. Identification of metabolites related to mechanisms of resistance in barley against Fusarium graminearum, based on mass spectrometry. Plant Molecular Biology. 77:355-370.
Kumaraswamy GK, Kushalappa AC, Choo TM, Dion Y. and Rioux S. 2011. Mass spectrometry based metabolomics to identify potential biomarkers for resistance in barley against fusarium head blight (Fusarium graminearum). Journal of Chemical Ecology 37:846-856.
Kumaraswamy GK, Bollina V, Kushalappa AC, Choo TM, Dion Y., Rioux S., and Faubert D. 2011. Metabolomics technology to phenotype resistance in barley against Gibberella zeae.. European J. Plant Pathology 130:29-43.
Bollina, V., Kumaraswamy, KG., Kushalappa, AC., Choo TM., Dion Y., Rioux S., Faubert D. and Hamzehzarghani H. 2010. Mass spectrometry based metabolomics application to identify quantitative resistance related metabolites in barley against fusarium head blight. Molecular Plant Pathology 11:769-782.
Kushalappa, AC., Vikram, A. and Raghavan, GSV. 2008. Metabolomics of headspace gas for diagnosing diseases of fruits and vegetables after harvest. Stewart Posthar. Tech. 4:1-7.
Paranidharan, V., Abu-Nada, Y., Hamzehzarghani, H., Kushalappa, A. C., Dion, Y., Rioux, S., and Comeau, A. 2008. Resistance related metabolites in wheat against Fusarium graminearum and the virulence factor, DON. Botany 86: 1168-1179.
Hamzehzarghani, H., Paranidharan, V., Abu-Nada, Y., Kushalappa, A. C., Dion, Y., Rioux, S., Comeau, A. Yaylayan, V. and Marshall, W. D. 2008. Development of metabolic profiling technology for potential high throughput screening of quantitative resistance in wheat cultivars against fusarium head blight. Can. J. Plant Path. 30:24-36.
Abu-Nada, Y., Kushalappa, A. C., Marshall, W., Yaylayan, V., Al-Mughrabi, K. and Murphy, A. 2007. Temporal dynamics of pathogenesis related metabolites and their plausible pathways of induction in potato leaves following inoculation with Phytophthora infestans. European J. Plant Path. 118:375-391.