Manuel Ospina-Giraldo

I teach Molecular Genetics, Plant Pathology, and Genomics. I am a member of the Oomycete Molecular Genetics Research Collaboration Network that sequenced and annotated the genomes of three important plant pathogens, Phytophthora infestans, Phytophthora ramorum and Phytophthora sojae.

Research in my laboratory focuses on the study of pathogenicity-related genes in fungal and oomycete pathogens that cause disease in life-sustaining agricultural crops, the plant genes involved in the defense mechanisms, and the genetic diversity of specific plant pathogens currently found in Pennsylvania.

Investigations in my laboratory focus on the interactions of plants and fungal and oomycete pathogens at the molecular level. Three projects are in progress: analysis and determination of the role of cell wall-degrading enzymes and inhibitors of plant defense proteins in pathogenicity, cloning and characterization of plant genes conferring resistance to fungal and oomycete diseases, and molecular characterization of races of Phytophthora infestans and P. sojae found in Pennsylvania.

Project 1

Genes encoding cell wall-degrading enzymes and inhibitors of plant defense proteins constitute excellent candidates for insertional mutagenesis studies aimed at determining their precise role in the pathogenicity process. In addition, advances in genome sequencing of three species of the genus Phytophthora have facilitated the identification and characterization of factors involved in regulating the penetration and colonization of the host plant.  Molecular, genomic and bioinformatic approaches are being used to elucidate the microbial pathogenicity mechanisms and understand how oomycetes can overcome the morphological, biochemical and physiological mechanisms of defense in various parts of the plant.

Project 2

Concomitantly with my studies on fungal pathogenicity, I am interested in pursuing investigations focusing on the search for plant genes conferring resistance to fungal and oomycete diseases. In my current research on potato plants I have identified several genes that appear to be involved in resistance to Phytophthora infestans race 9, and I am very interested in advancing these investigations. The significance of this research is compounded by the fact that both mating types of P. infestans have been found in the United States, making the emergence of new races by sexual recombination a very likely event. Such an increased genetic variability in the pathogen almost always renders traditional disease management less efficient. However, the use of resistance genes, introduced by molecular approaches, may successfully complement the current control measures.

Project 3

A third project of utmost importance is the molecular characterization of races of Phytophthora infestans and P. sojae found in Pennsylvania. Determining the pathogens’ genetic diversity is a critical step that would augment basic studies on pathogenicity. PCR amplification and sequencing of the internal transcribed spacers (ITS) 1 and 2 could be used to aid in isolate identification and race classification of P. infestans, and P. sojae.

If you are interested in working in my lab, please do not hesitate to contact me.

Representative Publications:

• Grams, N. and Ospina-Giraldo, M.D. 2019. Increased expression of Phytophthora sojae genes encoding membrane-degrading enzymes suggests an early onset of necrotrophy during Glycine max infection. Fungal Genet. Biol. 133: 103268.
• Grams, N., Komar, H., Jainchill, D., and Ospina-Giraldo, M.D. 2019. Comparative expression analysis of Phytophthora sojae Polysaccharide Lyase family 3 (pectate lyase) genes during infection of the soybean Glycine max. BMC Phytopathol. Res. 1:15.
• Madison, C. and Ospina-Giraldo, M.D. 2018. Validation and expression analysis of predicted miRNAs in Phytophthora infestans and Phytophthora sojae. J. PA Acad. Sci. 92: 53-67.
• Hinkel, L. and Ospina-Giraldo, M.D. 2017. Functional analyses of the chitin synthase gene of Phytophthora spp. in mycelia and infected tissues of potato and soybean. Curr. Genet. 63: 909-921. DOI: 10.1007/s00294-017-0687-6.
• Horowitz, B. B. and Ospina-Giraldo, M.D. 2015. The pectin methylesterase gene complement of Phytophthora sojae: structural and functional analyses, and the evolutionary relationships with its oomycete homologs. PLoS ONE 10: e0142096.
• Mingora, C., Ewer, J., and Ospina-Giraldo, M.D. 2014. Comparative structural and functional analysis of genes encoding pectin methylesterases in Phytophthora spp. Gene 538: 74–83.
• Andersen, K. and Ospina-Giraldo, M.D. 2011. Relative disease susceptibility of cultivated varieties of potato to different isolates of Phytophthora infestans. J. PA Acad. Sci. 85: 140-146.
• Andersen, K. and Ospina-Giraldo, M.D. 2011. Assessment of the effect of temperature on the late blight disease cycle using a detached leaf assay. J. PA Acad. Sci. 85: 165-173.
• Jones, R.W. and Ospina-Giraldo, M.D. 2011. Novel cellulose-binding-domain protein in Phytophthora is cell wall localized. PLoS ONE 6(8): e23555. doi:10.1371/journal.pone.0023555.
• Ospina-Giraldo, M.D., Griffith, J., Laird, E., and Mingora, C. 2010. The CAZyome of Phytophthora spp.: A comprehensive analysis of the gene complement coding for carbohydrate-active enzymes in species of the genus Phytophthora. BMC Genomics 11: 525.
• Ospina-Giraldo, M.D., McWalters, J., and Seyer, L. 2010. Structural and functional profile of the carbohydrate esterase gene complement in Phytophthora infestans. Curr. Genet. 56: 495-506. DOI: 10.1007/s00294-010-0317-z
• Haas B. J., Kamoun S., Zody M. C., Jiang R. H., Handsaker R. E., Cano L. M., Grabherr M., Kodira C. D., Raffaele S., Torto-Alalibo T., Bozkurt T. O., Ah-Fong A. M., Alvarado L., Anderson V. L., Armstrong M. R., Avrova A., Baxter L., Beynon J., Boevink P. C., Bollmann S. R., Bos J. I., Bulone V., Cai G., Cakir C., Carrington J. C., Chawner M., Conti L., Costanzo S., Ewan R., Fahlgren N., Fischbach M. A., Fugelstad J., Gilroy E. M., Gnerre S., Green P. J., Grenville-Briggs L. J., Griffith J., Grunwald N. J., Horn K., Horner N. R., Hu C. H., Huitema E., Jeong D. H., Jones A. M., Jones J. D., Jones R. W., Karlsson E. K., Kunjeti S. G., Lamour K., Liu Z., Ma L., Maclean D., Chibucos M. C., McDonald H., McWalters J., Meijer H. J., Morgan W., Morris P. F., Munro C. A., O’Neill K., Ospina-Giraldo M., Pinzon A., Pritchard L., Ramsahoye B., Ren Q., Restrepo S., Roy S., Sadanandom A., Savidor A., Schornack S., Schwartz D. C., Schumann U. D., Schwessinger B., Seyer L., Sharpe T., Silvar C., Song J., Studholme D. J., Sykes S., Thines M., van de Vondervoort P. J., Phuntumart V., Wawra S., Weide R., Win J., Young C., Zhou S., Fry W., Meyers B. C., van West P., Ristaino J., Govers F., Birch P. R., Whisson S. C., Judelson H. S., and Nusbaum, C. 2009. Genome sequence and analysis of the Irish potato famine pathogen Phytophthora infestans. Nature 461: 393-398.
• Costanzo, S., Ospina-Giraldo, M.D., Deahl, K., Baker, J., and Jones, R. 2007. Alternate Intron Processing of Family 5 Endoglucanase Transcripts from the Genus Phytophthora. Curr. Genet. 52: 115-123.
• Tyler, B. et al. 2006. Phytophthora genome sequences uncover evolutionary origins and mechanisms of pathogenesis: genome sequences of the soybean pathogen Phytophthora sojae and the sudden oak death pathogen Phytophthora ramorum reveal a photosynthetic past and recent massive expansion and diversification of potential pathogenicity gene families. Science. Accepted for publication.