Brett M. Tyler was born on August 29, 1955, in Vancouver, Canada. He received his B.Sc. (Hons) degree from Monash University, Australia, in 1977 and his Ph.D. degree in medical biology from the University of Melbourne, Australia, in 1981. He was a postdoctoral fellow from 1982 to 1984 at the University of Georgia and a research fellow at the Australian National University, Australia, from 1984 to 1988. He was appointed an associate professor in the Department of Plant Pathology at the University of California, Davis in 1988 and promoted to full professor in 1994. In 2002, he accepted a position at the Virginia Polytechnic Institute and State University as professor in the Virginia Bioinformatics Institute and in the Department of Plant Pathology, Physiology and Weed Science.
Tyler’s research in plant pathology has focused on understanding the molecular mechanisms by which oomycete pathogens, such as Phytophthora, overcome plants’ defense mechanisms. Tyler’s first major contribution to the molecular genetics of oomycetes was his development of a DNA transformation system for Phytophthora infestans and P. sojae in collaboration with Howard Judelson and Richard Michelmore, thus opening the possibility of direct functional manipulation of oomycete genes. In 1994, in collaboration with Helga Forster and Michael Coffey, he used molecular markers to demonstrate sexual reproduction in the clonally reproducing species P. sojae. The recognition that outcrossing had caused the development of many new races of P. sojae led his team to develop the first Mendelian genetic system for this pathogen, opening the way for genetic identification and map-based cloning of many genes. In 1995, he began building genomics resources for P. sojae and, in 1997, founded the community-based Phytophthora Genome Initiative, with Bruno Sobral, to build EST and genome sequencing programs for Phytophthora species. This initiative was highly successful in obtaining private and federal funding, resulting in large EST collections for P. sojae and P. infestans and in oomycete genomics databases at the National Center for Genome Resources and the Virginia Bioinformatics Institute. In 2002, he and his collaborators won funding for the sequencing of P. sojae and P. ramorum. Building on these first two genome sequences, Tyler was awarded funding for sequencing the genome of the Arabidopsis downy mildew pathogen Hyaloperonospora parasitica in 2004, enabling the exciting fusion of oomycete genomics with Arabidopsis genetic resources. Other members of the Phytophthora Genome Initiative have leveraged the P. sojae and P. ramorum sequences to obtain funding for genome sequencing of P. infestans, P. capsici, and Pythium ultimum. Most recently, Tyler has received funding to complete the P. sojae genome sequence and integrate all the oomycete genome sequences into a single resource, thus providing the community with an invaluable resource for future research. Tyler also has created an Affymetrix GeneChip microarray for P. sojae to facilitate functional genomics studies by the community. He also is leading the multi-institutional PAMGO project to develop gene ontology terms for describing gene functions in a broad diversity of plant-associated microbes.
Tyler’s research into the biology of oomycetes has made major contributions to understanding the molecular basis of recognition between Phytophthora species and their hosts. His team characterized elicitin proteins secreted by many Phytophthora species and demonstrated their importance in regulating the interaction of Phytophthora species with Nicotiana species. In collaboration with Paul Morris, his team characterized the recognition by P. sojae hyphae and swimming zoospores of isoflavone signals released by soybean roots. In 2004, his team described the cloning of the first avirulence gene from an oomycete, Avr1b, showing that it encoded a highly polymorphic protein and predicting that the protein should have the ability to enter plant cells. Searching the P. sojae and P. ramorum genomes with the Avr1b sequence, he and his collaborators discovered a very large family of effector proteins with a conserved N-terminal motif called RXLR-dEER. The family is present in all sequenced oomycete genomes and includes 12 cloned avirulence genes. The RXLR-dEER motif was widely predicted to carry the effector protein into plant cells and Tyler and others have recently proven this experimentally. The identification of the RXLR-dEER family of effectors has created a rush of excitement to understand the functions of these effectors. In addition to his research on effectors, Tyler currently has active soybean and P. sojae functional genomics research projects focused on understanding the complex network of genetic interactions between the host and pathogen that underlies the disease interaction. Understanding the interaction from a many-genes-to-many-genes perspective will lay the groundwork for long-term and durable technologies for improving plant resistance against oomycete pathogens.
A hallmark of Tyler’s visionary leadership has been his determination that the oomycete molecular genetics community should have a strong spirit of collaboration, that tools and knowledge should be rapidly shared prior to publication, and that the careers of new entrants to the community should be actively fostered. Building on the Phytophthora Genome Initiative, he obtained a community-building Research Collaboration Network grant for the Phytophthora molecular genetics community from 2002 to 2007 and a follow-up grant for the oomycete genomics community from 2007 to 2012. Tyler has actively fostered the career of many new oomycete molecular genetics researchers; the majority of his research grants have been in partnership with junior colleagues. Several of his postdoctoral fellows have become major contributors to the field, including APS Ruth Allen Award winner Howard Judelson and APS Syngenta Award winner Sophien Kamoun. The community that began with less than five research groups in 1986 now has more than 80 oomycete molecular genetics and genomics researchers worldwide. The genomic tools and resources that Tyler and his collaborators developed and the culture of cooperation that he has fostered within the community have transformed the field of oomycete molecular genetics over the last 20 years. This field, which was once regarded as a “career destroyer,” is now vibrant and contributing cutting-edge knowledge to the field of molecular plant-microbe interactions at large.
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