Mary-Dell Chilton

Mary-Dell Chilton

Mary-Dell Chilton, PhD, distinguished science fellow and founder of Syngenta Biotechnology, Inc., is a key founder of modern plant biotechnology. Chilton received an honorary doctor of science degree on May 15, 2015.


While on the biology faculty at Washington University in St. Louis during the late 1970s and early 1980s, Dr. Chilton led a collaborative research study that produced the first transgenic (genetically engineered) plants.

Her work pioneered the field of agricultural biotechnology and forever changed the way plant genetic research is conducted. She is recognized for her groundbreaking research and its continued impact on agriculture.

Dr. Chilton’s molecular research concerned a plant bacterium called Agrobacterium tumefaciens that creates a suitable environment for itself when it infects a plant by inserting some of its genes in the plant’s genome. The genes cause the plant to grow a gall, or tumor.

Dr. Chilton showed that it was possible to remove the tumor-causing genes in Agrobacterium and replace them with foreign genes. In this way, Agrobacterium was disarmed and could be used to transfer desirable genes into crop plants.

She has been called the “queen of Agrobacterium” in honor of this achievement.

A native of Indianapolis, Indiana, she earned a bachelor’s degree, with highest distinction, in 1960, and a doctorate in 1967, both in chemistry from the University of Illinois at Urbana-Champaign.

She then moved to the University of Washington in Seattle, where she held both a postdoctoral fellowship and a faculty position.

Chilton paved the way for crop improvement

There she led a research team that was the first to demonstrate that Agrobacterium transferred DNA into the genome of a host plant, changing it forever. This discovery, instrumental in the eventual capacity to genetically modify plants, was published in Cell, the leading journal in molecular biology, in 1977.

In 1979, she moved to Washington University in St. Louis where her research team demonstrated that the genes responsible for causing disease could be removed from the bacterium without affecting its ability to insert other genes into a plant cell.

In 1982, Dr. Chilton led the first team to successfully transfer a gene of choice into tobacco plants using Agrobacterium. In collaboration with Andrew Binns of the University of Pennsylvania, the team eventually grew the transformed cells into the first transgenic plants and showed that the trait was passed on to their progeny.

Her work paved the way for crop improvement by genetic engineering and earned her the 2013 World Food Prize, often referred to as the “Nobel Prize for food and agriculture.”

Washington University established an endowed professorship in her name, the Mary-Dell Chilton Distinguished Professor in Arts & Sciences. In 2009, biologist Barbara A. Schaal, PhD, now dean of the faculty of Arts & Sciences, was installed as the inaugural holder of the professorship.

At the time of the installation ceremony, which Dr. Chilton attended, Chancellor Mark S. Wrighton referred to her “astonishing discovery that led to the emergence of the new scientific field of plant genetic engineering. This discovery revolutionized plant science and gave plant geneticists who followed, such as Barbara Schaal, the ability to translate that knowledge into improving the world’s food crops.”

Dr. Chilton left Washington University in 1983 to accept a position in the private sector at CIBA-Geigy Corporation, which later became Syngenta Biotechnology, Inc., in Research Triangle Park, North Carolina.

Her tenure there has spanned both research and administrative roles, including vice president of agricultural biotechnology and principal scientist.

Dr. Chilton wrote in Plant Physiology that her work acted as an inspiration to others who have developed different means of DNA delivery.

Noting that essentially all major crop plants can be or are being genetically engineered, she wrote that “perhaps the most important legacy from Agrobacterium has been its inspiration of confidence that foreign gene integration, even though DNA is sometimes delivered artificially, is a perfectly natural process. My most fervent wish is that well-meaning environmental proponents will come to recognize this and embrace the technology based on it.”

Inducted into the National Academy of Sciences in 1985 and the American Academy of Arts and Sciences in 1993, Dr. Chilton also received The Franklin Institute’s Benjamin Franklin Medal in Life Sciences in 2002 and was inducted into the National Inventors Hall of Fame in March 2015, among other major honors.

Dr. Chilton and her husband, the late Scott Chilton, PhD, a professor of botany at North Carolina State University, have two sons, Mark and Andrew, and two grandchildren.

The couple personally supported many students both financially and academically over the years, temporarily housing more than 40 international students in their home, which they referred to as the “Chilton Hilton.”

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