‘Pigment of the imagination’ named National Historic Chemical Landmark
ARS scientist Harry A. Borthwick, Ph.D., helped discover the plant photoreceptor called phytochrome
The discovery of phytochrome, a regulator of plant growth and development, would be designated a National Historic Chemical Landmark on Oct. 21 by the American Chemical Society (ACS). This discovery explains how plants are able to regulate their germination, flowering, fruiting and other development processes over their growing season by detecting changes to light and darkness.
In 1959 after a 40-year research program, scientists at the U.S. Department of Agriculture (USDA) in Beltsville, Maryland, first detected phytochrome, a light-reactive pigment found in nearly all plants. The pigment explains how plants like black-eyed susans know to flower during the long days of summer while chrysanthemums wait until the fall. Knowledge of phytochrome has allowed plant scientists to produce crops for seasons and latitudes that were not previously possible.
“The discovery of phytochrome explains how plants germinate, grow and flower in predictable cycles over the course of a year,” says Pat N. Confalone, Ph.D., chair of the ACS Board of Directors. “This extraordinary collaboration between physiologists, biologists, chemists and other scientists at the USDA demonstrates the importance of federal research in the fundamental sciences to unlock nature’s most powerful mysteries.”
“Phytochrome was one of the most important discoveries in plant science of the 20th century, making possible many valuable leaps forward for agricultural science, such as growing crops in new seasons and latitudes and even creating new ways to protect plants from pests,” says Agricultural Research Service (ARS) Administrator Chavonda Jacobs-Young, Ph.D. The discovery of phytochrome took place at the Beltsville Agricultural Research Center (BARC), which is part of ARS, USDA's chief intramural scientific research agency.