Mary-Dell Chilton (born February 2, 1939, in Indianapolis, Indiana) is a key founder of modern plant biotechnology. She was the first (1977) to demonstrate the presence of a fragment of Agrobacterium Ti plasmid DNA in the nuclear DNA of crown gall tissue. Her research on Agrobacterium also showed that the genes responsible for causing disease could be removed from the bacterium without adversely affecting its ability to insert its own DNA into plant cells and modify the plants genome. Chilton described what she had done as disarming the bacterial plasmid responsible for the DNA transfer. She and her collaborators produced the first genetically modified plants using Agrobacterium carrying the disarmed Ti plasmid (1983). She has been called the "queen of Agrobacterium."
Chilton received her Ph.D. from the University of Illinois. While on faculty at Washington University in the late 1970s and early 1980s, Chilton led a collaborative research study that produced the first transgenic plants. For her work with Agrobacterium tumefaciens, she has been recognized with an honorary doctorate from the University of Louvaine, the John Scott Medal from the City of Philadelphia, membership in the United States National Academy of Sciences, and the Benjamin Franklin Medal in Life Sciences from the Franklin Institute. She was honored by the Crop Science Society of America in 2011 with the organization's Presidential Award.
Chilton is a Distinguished Science Fellow at Syngenta Biotechnology, Inc., She began her corporate career in 1983 with CIBA-Geigy Corporation (a legacy company of Syngenta). Chilton is author of more than 100 scientific publications. In honor of her many achievements, in 2002 Syngenta announced creation of the Mary-Dell Chilton Center – a new administrative and conference center which was added to the company's facility in Research Triangle Park, N.C.