The society grants this honor to a current APS member in recognition of distinguished contributions to plant pathology or to The American Phytopathological Society. Fellow recognition is based on significant contributions in one or more of the following areas: original research, teaching, administration, professional and public service, and/or extension and outreach.
Brian J. Steffenson is an outstanding scientist, educator, and international leader who has made numerous contributions that significantly advanced the field of plant pathology. His worldwide collaborative efforts and cutting-edge research have resulted in new methodologies for identifying disease resistance genes. These advancements proved to be crucial for developing resistant varieties to help feed the growing world population. Since his first publication in Plant Disease in 1983, he has published over 200 journal articles in Science, Nature Biotechnology, PNAS, and Phytopathology, among others. The Impact of his research is great, and Google Scholar statistics show over 12,800 citations of his publications. Steffenson has been a member of APS since 1980.
Brian Steffenson was born in Minneapolis, MN, and received his B.S. and M.S. degrees at the University of Minnesota. He received a Ph.D. in plant pathology from the University of California-Davis in 1988 and then accepted a position at North Dakota State University, where he rose to the rank of full professor. In 2000, he accepted a position at the University of Minnesota, where he is currently a distinguished global professor and Lieberman-Okinow Endowed Chair of Cereal Disease Resistance. The overarching objective during Steffenson’s career has been the control of plant diseases so a sufficient supply of quality grain can be produced to feed the world’s population. Although he is considered a world authority in a number of specific areas (e.g., host-pathogen interactions in the barley/stem rust, leaf rust, and spot blotch pathosystems), it is his research on plant disease resistance that has contributed most significantly and broadly to plant pathology and other allied disciplines. Steffenson is distinguished in many areas, including 1) genetics of durable stem rust and spot blotch resistance in barley; 2) exploiting cereal wild relatives for disease resistance and other economically important traits; 3) identification and cloning of disease resistance genes in cereals; 4) development and validation of multigene transgenic wheats for rust resistance; and 5) genetics of virulence in plant-pathogenic fungi.
A major focus of Steffenson’s work is investigation of the genetic basis of durable resistance in barley to stem rust and spot blotch. These two pathogens differ markedly in their biology and pathogenicity; thus, research in these systems can reveal broadly applicable principles for developing durably resistant crops. Steffenson discovered that durable resistance to both pathogens was controlled by just one or two large effect genes, and not a complex of many small-effect genes, as reported in other pathosystems. He determined that durable stem rust resistance in barley was conferred by a single gene (Rpg1) that is effective throughout the life of the plant and is functional in all barley genetic backgrounds, while two genes that are differentially expressed in seedlings and adult plants control durable spot blotch resistance. Steffenson’s research led to the map-based cloning of Rpg1. This was the first rust resistance gene isolated from a small-grain cereal and was a key advance in demonstrating that such genes could be cloned from plants with very large genomes like barley. Functional analysis on Rpg1 led to groundbreaking new data on how plant resistance genes first perceive the presence of a pathogen to activate defense responses. He also discovered the first molecular signaling interactions between plant and pathogen that occur within just five minutes after a rust spore lands on a leaf—and long before the spore ever germinates and invades the plant. This finding changed the paradigm by which researchers investigate early events of host-parasite interactions. A recent significant work was deciphering, through genomics-based evidence, the origin of the Ug99 isolate of the stem rust pathogen from a somatic hybridization event and a whole nucleus swap of two isolates. Ug99 possesses a wide virulence spectrum and is a major threat to food security worldwide.
Another thrust of Steffenson’s work has been the systematic exploitation of wild cereal species for economically important genes. He has assembled large collections of wild barley, Sharon goatgrass, elongated goatgrass, and wild emmer wheat from across their ecogeographic ranges to capture as much useful genetic variation as possible for cultivated barley and wheat improvement. Steffenson has now characterized these collections for resistance to the rust diseases and other agronomically important traits. To effectively utilize this genetic variation, Steffenson collaborated in developing new and more powerful approaches for rapidly cloning resistance genes from plants, called association genetics-resistance gene enrichment sequencing (Ag-RenSeq). This work, published in Nature Biotechnology in 2019 and a second paper in 2020, is changing the way researchers clone resistance genes from plants, enabling rapid identification of NBS-LRR-type resistance genes that have a role in response to specific pathogens. Steffenson and colleagues demonstrated the utility of using the Ag-RenSeq pipeline to identify gene sequences of rust resistance genes in Aegilops tauschii and wild barley. Steffenson also established the International Wild Barley Sequencing Consortium comprised of over 50 researchers from 14 different countries. The availability of sequence data from over 280 wild barley accessions and a wild barley pan-genome will greatly facilitate the cloning of many more resistance genes, which can be pyramided into cultivars to enhance their durability.
In 2010, Steffenson helped to establish and is currently the codirector of the Stakman-Borlaug Center for Sustainable Plant Health. This center raises the international visibility and stature of plant disease research and leads collaborative research projects of groups throughout the world, creating a larger community of scientists working together in international research and training. Steffenson’s commitment to global research and education is demonstrated in the new generation of scientists that has come out of his program. In additional to dozens of undergraduates and 16 graduate students, he has trained over 50 international visiting students, postdocs, and scientists in his lab. This extraordinary effort was one reason he received the Michael P. Malone International Leadership Award from the Association of Public and Land-Grant Universities and the Award for Global Engagement and Distinguished Global Professor from the University of Minnesota.