Theodor O. Diener was a scientist who discovered the tiny infectious disease agents now known as viroids.
- Died: March 28, 2023 (Who else died on March 28?)
- Details of death: Died at his home in Beltsville, Maryland at the age of 102.
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Theodor O. Diener’s legacy
Born in Switzerland, Theodor O. Diener immigrated to the U.S. in 1949 and began working as a plant pathologist for the Agricultural Research Service. There, he worked to discover the cause of potato spindle tuber disease, which had been plaguing crops for decades. Diener determined in 1971 that the disease was caused not by a virus, but by a much smaller infectious agent – one-eightieth the size of a virus. He named these tiny particles viroids and proved that they were capable of attacking and damaging organisms.
Diener’s discovery was compared to the discoveries of bacteria and viruses in terms of its importance to health and science. He was honored with the National Medal of Science in 1987, awarded to him by President Ronald Reagan (1911–2004). Diener continued to study viroids throughout his career, eventually writing two books and dozens of peer-reviewed articles on the infectious agents.
Full obituary: The Washington Post
