Theodor Otto Diener (born 28 February 1921) is a Swiss-American plant pathologist. In 1971, he discovered that the causative agent of the potato spindle tuber disease is not a virus, but a novel agent, which consists solely of a short strand of single-stranded RNA without a protein capsid, eighty times smaller than the smallest viruses. He proposed to name it, and similar agents yet to be discovered,

viroids Viroids are small single-stranded, circular RNAs that are infectious pathogens. Unlike viruses, they have no protein coating. All known viroids are inhabitants of angiosperms (flowering plants), and most cause diseases, whose respective economi ...

. Viroids displaced viruses as the smallest known infectious agents.

Biography

Diener was born in Zürich, Switzerland. He attended the Swiss Federal Institute of Technology, from which he graduated with a Dr.sc.nat.ETH degree in 1946. After graduation, he worked as a research assistant at the Swiss Federal Experiment Station for Viticulture and Horticulture at Wädenswil,Independent Academia
/ref> where he discovered on leaves of a cherry tree the first occurrence in more than 100 years of a rust fungus (''Puccinia cerasi''), a fungus which is common south of the Alps, but is rarely seen in the north. In 1949, he emigrated to the United States, where, after a brief tenure at the Rhode Island State College, he accepted a position as Assistant Plant Pathologist at Washington State University's outlying Irrigation Experiment Station in Prosser, where he showed that an unusual amino acid,

pipecolic acid Pipecolic acid (piperidine-2-carboxylic acid) is an organic compound with the formula HNC5H9CO2H. It is a carboxylic acid derivative of piperidine and, as such, an amino acid, although not one encoded genetically. Like many other α-amino acids, p ...

, accumulates only in peach leaves bearing symptoms of Western-X-Disease. and that injection of the amino acid into healthy peach seedlings resulted in abnormalities which strikingly resembled disease symptoms, thus indicating that pipecolic acid is intimately associated with the disease's molecular pathogenesis. In 1959, Diener joined the US Department of Agriculture's Agricultural Research Service Pioneering Laboratory for Plant Virology at the Agricultural Research Center in Beltsville, Maryland, where he investigated the cause of the potato spindle tuber disease. This led to the unexpected discovery of the causative agent, a small RNA molecule, eighty times smaller than the smallest known viruses, for which he proposed the term

viroid Viroids are small single-stranded, circular RNAs that are infectious pathogens. Unlike viruses, they have no protein coating. All known viroids are inhabitants of angiosperms (flowering plants), and most cause diseases, whose respective economi ...

. Later, viroids were characterized as single stranded covalently closed circular RNA molecules occurring as highly base-paired rod-like structures. Viroids, together with viroid-like satellite RNAs have been officially endorsed by the International Committee for Virus Taxonomy (ICTV) as a novel order of subviral agents, which, in its 2014 publication, encompassed 2 families, 8 genera and 32 species. In 1989, Diener hypothesized that the unique properties of viroids make them more plausible candidates as "living relics" of a hypothetical, pre-cellular RNA world than are Introns or other RNAs then considered as such. In 2016, Diener reevaluated his hypothesis, with the result that both reviewers agreed that Diener's hypothesis was still valid, but that alternative hypotheses positing a more recent origin of viroids from cellular RNAs needed also to be considered.

Awards and honors

*1968: Campbell Award,

American Institute of Biological Sciences The American Institute of Biological Sciences (AIBS) is a nonprofit scientific charity. The organization’s mission is to promote the use of science to inform decision-making and advance biology for the benefit of science and society. Overvie ...

*1969: Superior Service Award,

U.S. Department of Agriculture The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of comme ...

*1973: Fellow Award;

American Phytopathological Society The American Phytopathological Society (APS) is an international scientific organization devoted to the study of plant diseases (phytopathology). APS promotes the advancement of modern concepts in the science of plant pathology and in plant healt ...

*1975: Alexander von Humboldt Award, Alexander von Humboldt Society *1976: Ruth Allen Award:

*1977: Elected Member; U.S. National Academy of Sciences *1978: Elected Fellow,

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...

*1979: Elected Andrew D. White Professor-at-Large,

Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to tea ...

*1980: Elected member, Leopoldina, German Academy of Sciences *1987:

Wolf Prize in Agriculture The Wolf Prize in Agriculture is awarded annually by the Wolf Foundation in Israel. It is one of the six Wolf Prizes established by the Foundation and awarded since 1978; the others are in Chemistry, Mathematics, Medicine, Physics and the Arts. ...

, Wolf Foundation/ State of Israel *1987:

National Medal of Science The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral and social scienc ...

, USA *1988: E.C. Stakman Award,

University of Minnesota The University of Minnesota, formally the University of Minnesota, Twin Cities, (UMN Twin Cities, the U of M, or Minnesota) is a public land-grant research university in the Twin Cities of Minneapolis and Saint Paul, Minnesota, United States. ...

*1988: Distinguished Service Award, Potomac Division,

*1989: Inducted into Science Hall of Fame, Agricultural Research Service,

Agricultural Research Service
/ref> *1989: Named Distinguished Professor,

University of Maryland The University of Maryland, College Park (University of Maryland, UMD, or simply Maryland) is a public land-grant research university in College Park, Maryland. Founded in 1856, UMD is the flagship institution of the University System of M ...

College Park, MD College Park is a city in Prince George's County, Maryland, United States, and is approximately four miles (6.4 km) from the northeast border of Washington, D.C. The population was 34,740 at the 2020 United States Census. It is best known ...

*1994: Named Distinguished Professor Emeritus,

, College Park, MD *Diener published 2 books on viroids, 120 peer-reviewed articles, 53 chapters in books, and lectured on viroids worldwide

References

* USDA-ARS. 1989.
Tracking the Elusive Viroid
' {{DEFAULTSORT:Diener, Theodor 1921 births Living people American phytopathologists National Medal of Science laureates Members of the United States National Academy of Sciences Wolf Prize in Agriculture laureates 21st-century American botanists University of Maryland, College Park faculty Swiss emigrants to the United States

Biography

Awards and honors

See also

References