About Dr. Davis

Dr. Robert E. Davis was born in Brooklyn, NY, on January 27, 1939, of Robert S. and Cecelia Davis, and was raised in Warwick, RI, where attended Warwick High school and met his future wife of 58 years, Maryann Davis. He then went on to attend the University of Rhode Island, graduating Summa Cum Laude with a Bachelor’s of Science in Botany in 1961. He was awarded his Ph.D. in Plant Pathology from Cornell University, Ithaca, NY in 1967. Following a National Research Council Postdoctoral Fellowship with the USDA-ARS in Beltsville, MD from 1966 to 1967, he accepted a position as a Research Scientist in the Plant Virology/Molecular Plant Pathology Laboratory, where he remained as a full-time government scientist until his passing on July 18, 2019, a career that spanned 52 years. Over the course of his career Dr. Davis became the research leader of the Molecular Plant Pathology Laboratory, at the USDA Beltsville Agricultural Research Center, a member of the National Academy of Sciences, and a discoverer of the spiroplasma genus of plant microbes.

In the early 1970’s up to and including the time of his passing, Dr. Davis was one of the leading researchers and innovators in the field of phytoplasmas and spiroplasmas, plant pathogenic cell wall-less bacteria that evolved from walled bacterial ancestors and which possess genomes that are among the smallest known in bacteria, approaching the minimal sets of genes required for cellular life and parasitism in plants and insects. Dr. Davis developed several new scientific concepts and led the way toward discovery of an entirely new taxon of pathogens. In 1971, while looking for the causative agent in corn stunt disease, Dr. Davis was the first to discover a previously unidentified extremely narrow helical and motile filament that was present in every diseased culture and in no healthy culture. In a 1972 paper in Science reporting his findings, Dr. Davis coined the term “spiroplasma” for the corn stunt and other yet-to-be-discovered wall-less bacteria having helical cell shape. Shortly thereafter, the citrus stubborn wall-less microbe, previously reported as a non-helical MLO, was recognized as a helical microbe, and the term “spiroplasma” was adopted as a new genus name. 

Dr. Davis’s discovery of the spiroplasma class of organism is recognized as among the top ten milestones of the past century in plant pathology and opened an entirely new field in which diverse spiroplasma pathogens have subsequently been found. Today, following work in Dr. Davis’s laboratory and others, diverse Spiroplasma species are known as insect-transmitted pathogens of plants, as symbionts in ticks and diverse insects, as lethal pathogens in crustaceans such as some shrimp and crab, and as possible inhabitants of jellyfish, a deep-sea chiton, and a hadopelagic zone sea cucumber; and some can present risk of human infection. 

Most recently, Dr. Davis and his colleagues recently published the first completely sequenced genome of the corn stunt spiroplasma, Spiroplasma kunkelii, as well as the first completely sequenced genomes of the only other known plant pathogenic spiroplasmas, S. citri and S. phoeniceum. 

Important new insights into numerous plant diseases caused by poorly understood microbes were developed through national and international collaborative research teams led by Dr. Davis and his colleagues and whose contributions continue to impact basic science and provide solutions to economic problems in agriculture in the United States and elsewhere. During his career, Dr. Davis mentored many young scientists and students and helped establish molecular plant pathology laboratories worldwide, leaving an impressive legacy to the future of plant pathology.