Thomas J. Wolpert was born in Columbus, NE, on April 8, 1951. He received his B.S. degree in psychology/zoology at the University of Nebraska (1973), an M.S. degree in plant physiology at Purdue University (1979), and a Ph.D. degree in plant pathology at Purdue University (1983). Wolpert joined the Department of Botany and Plant Pathology at Oregon State University in 1989 as an assistant professor. He was promoted to associate professor in 1995 and to professor in 2002.
Wolpert has developed an international reputation for his contributions to our understanding of the molecular mechanisms of host-pathogen interactions through his meticulous studies of host-selective toxin (HST) biology and programmed cell death (PCD) of plants. Much of his work has focused on the action of victorin, a host-selective fungal toxin, and its role in the long-known disease called Victoria blight of oats. Isolates of the fungus Cochliobolus victoriae produce victorin, which is required for pathogenesis and induces rapid cell death only in susceptible, toxin-sensitive oat cultivars. Oat cultivars that carry a dominant, single gene designated Vb are sensitive to the toxin, whereas those lacking this gene are insensitive. A unique aspect of this system is that Vb is identical or closely linked to the Pc2 gene, which confers crown rust resistance, thus providing an opportunity to simultaneously elucidate mechanisms of both susceptibility and resistance.
Wolpert’s persistence resulted in his being able to isolate sufficient quantities of victorin, a very unstable molecule, thus allowing structural determination. Knowing the structure enabled him and his colleagues to identify reactive sites through biochemical modification of the molecule, and tag the molecule at specific sites for studies of its binding to host proteins. Wolpert and his students showed that victorin induces specific events characteristic of programmed cell death (apoptosis) that are characterized, in part, by the hallmark feature of internucleosomal DNA cleavage. Victorin structural analyses, binding studies, and physiological analyses of oat symptom development all indicated a mitochondrial role in PCD and victorin interaction with the mitochondrial glycine decarboxylase enzyme complex (GDC). In animals, mitochondrial function is a central component of PCD, realized through the opening of transition pores that regulate a mitochondrial permeability transition (MPT). Evidence suggested a similar mechanism in oats, and that MPT may be the mechanism by which victorin gains access to the mitochondrial matrix and binding components of the GDC. Indeed, Wolpert’s work led to the identification of two proteins of the GDC that bind victorin.
Though victorin sensitivity and susceptibility to C. victoriae were originally described in oats, Wolpert and colleagues have more recently demonstrated that sensitivity and disease susceptibility in Arabidopsis thaliana are conferred by LOV1, a gene encoding a coiled-coil-nucleotide-binding-leucine-rich repeat (CC-NB-LRR) protein. The structure of this gene for susceptibility thus is homologous to that of many known disease resistance genes in plants. In fact, they sequenced the LOV1 gene from 59 victorin-insensitive mutants and found that the spectrum of mutations causing LOV1 loss of function was similar to that found to cause loss of function of RPM1, a CC-NB-LRR resistance protein. They also found that many of the mutated residues in LOV1 are in conserved motifs required for resistance protein function. These data indicate that LOV1 may function similar to resistance proteins. Victorin sensitivity was found to be the prevalent phenotype in a survey of 30 Arabidopsis ecotypes, with very little genetic variation among LOV1 alleles. As selection would not be expected to preserve a functional LOV1 gene to confer victorin sensitivity and disease susceptibility, LOV1 may function as a resistance gene to a naturally-occurring pathogen of Arabidopsis, as well as susceptibility to C. victoriae.
Decades of meticulous work with the victorin system in Wolpert’s lab have thus established crucial links between genes for susceptibility and genes for resistance, and between gene products for virulence and those for avirulence. Additionally, Wolpert has made substantial contributions to the characterization and mode of action of toxins produced by Periconia circinata, Pyrenophora tritici-repentis, and Cephalosporium gramineum.
Wolpert’s work is highly respected among his peers nationally and internationally. His research has been supported by numerous peer-reviewed grants from both the National Science Foundation and the U.S. Department of Agriculture. Wolpert has been invited to present his research at the most prestigious forums, including the Banbury Conference, Gordon Conferences, and the U.S Japanese Symposia, for which he was a cochair of the organizing committee in 2003 and chair in 2010, as well as numerous departmental seminars. Among his colleagues, he is known as an exceptionally clear and deep thinker and an outstanding communicator. Wolpert is a legend within his own department for asking the first and most insightful question at nearly every seminar, regardless of the topic.
Wolpert’s exceptional mentoring skills have contributed substantially to the success of his laboratory. A member of his lab group recently noted that “Tom is an exceptional mentor. He is extremely supportive of all his lab members, above and beyond expectation. He serves as not only mentor to his students, he also serves as a ‘father-figure’ to them, a ‘grandfather-figure’ to their children, a shoulder to cry on, an open door and ear for listening, a source of sage advice, and a true friend.”
In addition to his exceptional research accomplishments, Wolpert had made substantial contributions to both teaching and service. He is a highly admired instructor who truly challenges his students to think, analyze, and criticize. His teaching responsibilities include a graduate course on the molecular basis of plant pathogenesis, playing an active role in the Molecular and Cellular Biology Program, providing guest lectures, and an internet II distance education class, all at the graduate level. In addition he has coinstructed an undergraduate course in plant physiology and is an undergraduate advisor to approximately 12 undergraduate biology majors each year. His service contributions include chair of The American Phytopathological Society Molecular and Cellular Phytopathology Committee, as well as numerous departmental and university committees, editorial boards, and grant panels.