The Discovery of Phytochrome

Abstract

AbstractThe US Department of Agriculture (USDA) Beltsville Agricultural Research Center (BARC) in Beltsville, Maryland, USA was recently designated an American Chemical Society National Historic Chemical Landmark for the seminal work of USDA scientists in the discovery of phytochrome, the ubiquitous plant pigment that controls plant growth and development in response to light. The discovery team was inspired by the work of Harry A. Borthwick and Marion W. Parker in the 1930s, which quantified photoperiodic phenomena and recruited Sterling B. Hendricks into the search for a chemical basis for non-photosynthetic responses of plants to light. Hendricks was a world famous soil chemist and member of the National Academy of Sciences before he became engaged in plant science. He hypothesized the existence of a photoreversible pigment that controls photoperiodism in flowering, seed germination, and many photomorphogenic processes in plants. Karl Norris and Warren Butler created the specialized spectrophotometer that was needed to detect the pigment in vivo. Harold W. (Bill) Siegleman provided the biochemical expertise to isolate the pigment. The scientific stars aligned in one place, as they rarely do, to make the discovery complete.