Leonardo De La Fuente
Postdoctoral Associate

Cornell University
Department of Plant Pathology
New York State Agriculture Experiment Station
Geneva, NY 14456

2005 Ph.D., Plant Pathology, Department of Plant Pathology, Washington State University, Pullman, WA, USA.      

2000 M.Sc, Biology, PEDECIBA (Program for the Development of Basic Sciences), University of the Republic, Montevideo, Uruguay.

E-mail: ld82@cornell.edu

Host: Harvey Hoch and Tom Burr

I am interested in the relationships between plant and associated bacteria. In my earlier research I have been studying rhizosphere beneficial bacteria which protect plants against diseases. I have been mainly interested in the mechanism of action of biological control of soilborne pathogens by Pseudomonas fluorescens, including the production of active secondary metabolites and enzymes. Most recently, I studied the process of rhizosphere colonization by P. fluorescens producing the antibiotic 2,4-diacetylphloroglucinol.

My postdoc position with Drs. Hoch and Burr is concerned with studying the plant pathogenic bacterium Xylella fastidiosa, the causal agent of Pierce's disease of grape. We will analyze the basic processes involved in xylem colonization by this bacterium, which ultimately leads to obstruction of sap flow and results in disease symptoms. The focus of our study is on bacterial movement and biofilm formation in the plant host.  Nano- and microfabrication approaches will be used to develop 'artificial' xylem vessels in which the bacteria can be observed temporally and spatially.

Professional Societies
American Phytopathological Society

Professional Assignments, Honors, and Awards     

Storkan-Hanes-McCaslin Foundation. 2004-2005. Grant: “Ecology of rhizosphere fluorescent Pseudomonas spp. involved in suppression of soilborne pathogens”.

Graduate and Professional Students Association of the Washington State University. Graduate student travel grant to attend the 2004 APS Annual Meeting held at Anaheim, California (USA)

APS Student Travel Award to attend the 2003 APS Annual Meeting held at Charlotte, North Carolina  (USA)

International Foundation for Science (IFS) (Sweden). 1999-2000. Grant: “Native fluorescent Pseudomonas as biocontrol agents of alfalfa seedling diseases”

Elected and Appointed Offices

Cursino, L., Y. Li, L. De La Fuente, C.D. Galvani, P. Zaini, H.C. Hoch, and T.J. Burr. 200X. Identification of pilL and chpY as components of a chemosensory signal transduction system that controls twitching motility in Xylella fastidiosa. Submitted to Journal of Bacteriology.

De La Fuente, L., T.J. Burr, and H.C. Hoch. 200X. Type I and type IV pili influence the rapid formation of cell aggregates of Xylella fastidiosa. Manuscript in preparation.

De La Fuente, L., T.J. Burr, and H.C. Hoch. 2007. Mutations in type I and type IV pilus biosynthetic genes affect twitching motility rates in Xylella fastidiosa. Journal of Bacteriology, 189:7507-7510.

De La Fuente, L., E. Montanes, Y. Meng, Y. Li, T.J. Burr, H.C. Hoch, and M. Wu. 2007. Assessing adhesion forces of type I and type IV pili of Xylella fastidiosa using a microfluidic flow chamber. Applied and Environmental Microbiology, 73:2690-2696.

Li, Y., G. Hao, C.D. Galvani, Y. Meng, L. De La Fuente, H.C. Hoch, and T.J. Burr. 2007. Type I and type IV pili of Xylella fastidiosa affect twitching motility, biofilm formation, and cell-cell aggregation. Microbiology, 153:719-726.

De La Fuente, L., O.V. Mavrodi, N. Bajsa, and D.V. Mavrodi. 200X. Antibiotics produced by fluorescent Pseudomonas. In Prospects and Applications for Plant-Associated Microbes. A Laboratory Manual, Part A: Bacteria. S. Sorvari and A. M. Pirttilä (Eds.). BioBien Innovations, Piikkiö, Finland.

De La Fuente, L., D.V. Mavrodi, L.S. Thomashow, and D.M. Weller. 2007. Utilization of trehalose, benzoate, valerate, and seed and root exudates by genotypes of 2,4-diacetylphloroglucinol producing Pseudomonas fluorescens. Soil Biology & Biochemistry,39:2712–2722.

Weller, D.M., B.B. Landa, O.V. Mavrodi, K. Schroeder, L. De La Fuente, S. Blouin-Bankhead, R. Allende-Molar, R.F. Bonsall, D.V. Mavrodi, and L.S. Thomashow. 2007. Role of 2,4-diacetylphloroglucinol-producing fluorescent Pseudomonas spp. in the defense of plant roots. Plant Biology, 9:4-20.

De La Fuente, L., B.B. Landa, and D.M. Weller. 2006. Host crop affects rhizosphere colonization and competitiveness of 2,4-diacetylphloroglucinol-producing Pseudomonas fluorescens. Phytopathology, 96:751-762.

De La Fuente, L., D.V. Mavrodi, B.B. Landa, L.S. Thomashow, and D.M. Weller. 2006. phlD-based genetic diversity and detection of genotypes of 2,4-diacetylphloroglucinol-producing Pseudomonas fluorescens. FEMS Microbiology Ecology, 56:64-78.

Validov, S., O. Mavrodi, L. De La Fuente, A. Boronin, D. Weller, L. Thomashow, and D. Mavrodi. 2005. Antagonistic activity among 2,4-diacetylphloroglucinol-producing fluorescent Pseudomonas spp. FEMS Microbiology Letters, 242:249-256.

De La Fuente, L., L.S. Thomashow, D.M. Weller, N. Bajsa, L. Quagliotto, L. Chernin, and A. Arias. 2004. Pseudomonas fluorescens UP61 isolated from birdsfoot trefoil rhizosphere produces multiple antibiotics and exerts a broad spectrum of biocontrol activity. European Journal of Plant Pathology, 110:671-681.

De La Fuente, L., L. Quagliotto, N. Bajsa, E. Fabiano, N. Altier, and A. Arias. 2002. Inoculation with Pseudomonas fluorescens biocontrol strains does not affect the symbiosis between rhizobia and forage legumes. Soil Biology & Biochemistry, 34:545-548.

Pérez, C., L. De La Fuente, A. Arias, and N. Altier. 2001. Uso de Pseudomonas fluorescentes nativas para el control de enfermedades de implantación en Lotus corniculatus. Agrociencias, 5:41-47.

De La Fuente, L., N. Bajsa, P. Bagnasco, L. Quagliotto, L. Thomashow and A. Arias. 2000. Antibiotic production by biocontrol Pseudomonas fluorescens isolated from forage legume rhizosphere. Proceedings of the 5th International PGPR Workshop. Córdoba, Argentina. http://www.ag.auburn.edu/argentina/pdfmanuscripts/delafuente.pdf

Bagnasco, P., L. De La Fuente, F. Noya, G. Gualtieri, and A. Arias. 1998. Fluorescent Pseudomonas spp. as biocontrol agents against forage legume root pathogenic fungi. Soil Biology & Biochemistry, 30:1317-1322.

Chernin, L., L. De La Fuente, V. Sobolev, S. Haran, C. E. Vorgias, A. Oppenheim, and
I. Chet. 1997. Molecular cloning, structural analysis and expression in Escherichia coli of a chitinase from Enterobacter agglomerans. Applied and Environmental Microbiology, 63:834-839.

Abstracts (Last 5 Years)

De La Fuente, L., T.J. Burr, and H.C. Hoch. 2007. Understanding control of Xylella fastidiosa cell aggregation: importance in colonization and biofilm development in grapevine and sharpshooter foregut. Pierce’s Disease Research Symposium. San Diego, CA.

Cursino, L., Y. Li, L. De La Fuente, C.D. Galvani, P. Zaini, H.C. Hoch, and T.J. Burr. 2007. The roles that different pili classes in Xylella fastidiosa play in colonization of grapevines and Pierce’s disease pathogenesis: chemosensory cluster controlling twitching motility. Pierce’s Disease Research Symposium. San Diego, CA.

De La Fuente, L., C.D. Galvani, L. Cursino, T.J. Burr, and H.C. Hoch. 2007. Xylella fastidiosa movement and biofilm formation studied in artificial xylem vessels. 2007. Phytopathology 97 (7): S26. APS Annual Meeting. San Diego, CA.

De La Fuente, L., L. Cursino, M. Wu, C.D. Galvani, T.J. Burr, and H.C. Hoch. 2007. Microfluidic chambers as ‘artificial’ xylem vessels used to study movement and biofilm formation of the bacterial plant pathogen Xylella fastidiosa. Cornell NanoScale Science & Technology Facility 30th Anniversary Meeting. Ithaca, NY.

De La Fuente, L., T.J. Burr, and H.C. Hoch. 2006. Evaluating the roles of pili in twitching and long distance movement of Xylella fastidiosa in grape xylem and in the colonization of sharpshooter foregut. Pierce’s Disease Research Symposium. San Diego, CA.

De La Fuente, L., Y. Li, C.D. Galvani, Y. Meng, G. Hao, T.J. Burr, and H.C. Hoch. 2005. Evaluating the roles of pili in twitching and long distance movement of Xylella fastidiosa: colonization and biofilm development. Pierce’s Disease Research Symposium. San Diego, CA.

Galvani, C.D., Y. Li, L. De La Fuente, G. Hao, T.J. Burr, and H.C. Hoch. 2005. Twitching motility among various wild-type isolates and pilus-defective mutants of Xylella fastidiosa. Pierce’s Disease Research Symposium. San Diego, CA.

De La Fuente, L., B.B. Landa, D.V. Mavrodi, L.S. Thomashow, and D.M. Weller. 2005. Competence among 2,4-diacetylphloroglucinol-producing Pseudomonas fluorescens differs in the wheat and pea rhizospheres. IOBC-meeting “Multitrophic interactions in soils”, p. 33. Wageningen, the Netherlands.

Mavrodi, D.V., S. Validov, O. Mavrodi, L. De La Fuente, A. Boronin, D.M. Weller, and L.S. Thomashow. 2005. Antagonistic activity among 2,4-diacetylphloroglucinol (DAPG)-producing fluorescent Pseudomonas spp. IOBC-meeting “Multitrophic interactions in soils”, p. 41. Wageningen, the Netherlands.

De La Fuente, L., B.B. Landa, L.S. Thomashow, and D.M. Weller. 2004. Dynamics of rhizosphere competition among genotypes of 2,4-diacetylphloroglucinol (DAPG)-producing Pseudomonas fluorescens depends on the host crop. Phytopathology 94 (6): S24. APS Annual Meeting. Anaheim, CA. USA.

Mavrodi D., S. Validov, O. Mavrodi, L. De La Fuente, A. Boronin, D. Weller, and L. Thomashow. 2004. Bacteriocin activity among 2,4-DAPG-producing fluorescent Pseudomonas spp. Phytopathology 94 (6): S67. Abstracts of the 2004 APS Annual Meeting. Anaheim, CA. USA. 

Landa, B.B., L. De La Fuente, and D.M. Weller. 2004.  Preferential colonization of the pea rhizosphere by genotypes of 2,4-diacetylphloroglucinol-producing Pseudomonas fluorescens strains. 5th European Conference on grain legumes “Legumes for the benefit of agriculture, nutrition and the environment”, p. 315. Dijon, France.

De La Fuente, L., D.V. Mavrodi, L.S. Thomashow, B.B. Landa, and D.M. Weller. 2003. PCR detection of specific 2,4-diacetylphloroglucinol-producing Pseudomonas fluorescens genotypes. Phytopathology 93(6): S20. APS Annual Meeting. Charlotte, NC. USA.

Mavrodi D., S. Validov, O. Mavrodi, L. De La Fuente, A. Boronin, D.Weller, and L. Thomashow. 2003. Bacteriocin activity among 2,4-DAPG-producing fluorescent Pseudomonas spp. Abstracts of the 11th International Congress on Molecular Plant-Microbe Interactions. St. Petersburg, Russia. p.362.

Yanes, M. L., L. De La Fuente, A. Arias, and N. Altier. 2003. Characterization of native fluorescent Pseudomonas spp. as biocontrol agents of alfalfa seedling diseases. Abstracts of the 6th International PGPR Workshop. Calicut, India. p. 628.

Yanes, M., L. De La Fuente, A. Arias, and N. Altier. 2003. Native fluorescent Pseudomonas as biocontrol agents of alfalfa seedling diseases. SAIB XXXIX Annual Meeting and SAB XXXII Annual Meeting. Bariloche, Río Negro, Argentina.

Bajsa, N., P. Vaz, L. De La Fuente, D. Davyt, C. Arnauld, P. Lemanceau, S. Gianinazzi, V. Gianinazzi-Pearson, and A. Arias. 2003. New antifungal compounds isolated from biocontrol Pseudomonas fluorescens and their effects on Rhizoctonia solani at cytological level. Abstracts of the 6th International PGPR Workshop. Calicut, India. p. 460.

Thomashow L. S., D.V. Mavrodi,  S. Validov, O.V. Mavrodi, L. De La Fuente, A. Boronin, and D.M. Weller. 2003. Bacteriocin production among 2,4-DAPG-producing fluorescent Pseudomonas spp. Abstracts of the 6th International PGPR Workshop. Calicut, India. p.627.

Bajsa, N., C. Arnould, D. Davyt, L. De La Fuente, L. Quagliotto, P. Lemanceau, S. Gianinazzi, V. Gianinazzi-Pearson, and A. Arias. 2002. Novel peptidic antibiotic isolated from Pseudomonas fluorescens CFBP2392: identification and effect on Rhizoctonia solani ultrastructure. Xth International Congress of Bacteriology and Applied Microbiology. Paris, France. p. 169.

Altier, N., C. Pérez, F. Ducamp, M. Cadenazzi, L. De La Fuente, N. Bajsa, L. Quagliotto, and A. Arias. 2002. Uso de Pseudomonas fluorescentes nativas para el control de enfermedades de implantación en leguminosas forrajeras. Resúmenes Mesa Redonda 10: Aplicaciones de sistemas microbianos en agricultura. Biolatina 2002. Montevideo, Uruguay.