Howard S. Judelson was born in the Bronx, New York. He received his B.S. degree in biochemistry from Cornell University in 1980 and his Ph.D. degree in molecular biology from the University of Wisconsin in 1985. Seeking experience in plant pathology, he then obtained a position as a postdoctoral fellow in the laboratory of Richard Michelmore at the University of California, Davis. After holding various positions at Davis until 1998, he relocated to the Department of Plant Pathology at the University of California at Riverside, where he is now an associate professor.
Dr. Judelson has made important contributions to the field of plant pathology by opening an important group of plant pathogens, the oomycetes, to molecular genetic analysis. Recognizing that oomycetes lacked taxonomic affinity with true fungi, Dr. Judelson developed new tools required for transformation by cloning the first oomycete genes, identifying promoters from those genes that could be used to drive the expression of marker genes, and devising methods for introducing DNA into oomycetes using Phytophthora infestans as a model. These studies led to the first report of stable transformation in 1991 and to further improvements in the transformation approach that have subsequently enabled co-transformation, gene silencing, and the transformation of other Phytophthora species.
The continued advancement of genetic tools remains a major focus of research in the Judelson laboratory, along with the application of these tools to study the developmental biology, evolution, and pathology of oomycetes. While Dr. Judelson’s work has focused mainly on P. infestans, he has helped extend transformation to other oomycetes and other species of Phytophthora, including P. parasitica, P. sojae, P. palmivora, and P. phaseoli, by providing hands-on training, vectors, and advice to others in the field.
The pace of research on Phytophthora has accelerated annually since Dr. Judelson’s pioneering work, and many studies are now being published that address genes involved in the growth, pathogenicity, and host specificity of Phytophthora species. It is even fair to say that without the demonstration that oomycetes are amenable to molecular manipulation, recent efforts to sequence the genomes of Phytophthora species probably would not be under way. Dr. Judelson’s efforts have stimulated studies across a broad range of oomycete–plant interactions that will impact plant pathology for years to come.