Joanne Chory

Joanne Chory grew up during the 1950s and 1960s in North Andover, Mass., just outside of Boston.  Four of her five siblings were boys — a factor she says helped “toughen” her up for her later work in male-dominated science laboratories. “My brothers were always hard on me,” she says. “So when I went to a lab with a strong male culture, it didn’t really bother me. It seemed familiar to me.”

Chory was interested in biology, particularly the diversity of microorganisms, from a somewhat early age (as a teenager she made a Winogradsky column, which she kept for years), but it took her “a long, long time,” she says, to decide on a career in science. That path became clear to her only after studying genetics while an undergraduate at Oberlin College in Ohio. “It was fascinating,” she recalls. After graduating from Oberlin with an honors degree in biology, Chory went on to the University of Illinois, “which had some great microbiologists.” One was her PhD advisor, Samuel Kaplan, with whom Chory studied photosynthetic bacteria. “Sam taught me how to do a good experiment,” she says. 

After completing her PhD in 1984, Chory moved back to Boston for a postdoctoral fellowship in plant molecular genetics with Frederick Ausubel at Harvard Medical School. At the time, most genetics labs were focusing on fruit flies. Chory, however, saw plant genetics as a much more promising area of research. “I thought, ‘I can contribute to that field. I can see a role in that field,’” she recalls. In the mid-1980s, plant research primarily involved food crops, such as maize or wheat, but Chory decided to study Arabidopsis thaliana, a small flowering mustard plant, primarily because of its relatively small genome. “We needed to get a model that could explain things in all the other 400,000 species of flowering plants,” she says.  

One of the molecular puzzles that Chory hoped A. thaliana would unlock was how young plants sense and respond to changes in light — a process essential to life on Earth. To answer that question, Chory performed what is now considered a seminal experiment. She put thousands of A. thaliana seeds treated with a DNA-damaging chemical onto Petri dishes, which were then wrapped in foil (to create a dark environment) and placed inside an incubator. When she took the dishes out a week later, she found that the seeds had mostly produced, as expected, etiolated seedlings — ones that were spindly, pale and leafless. But some of the seedlings were different: They had white leaves. Chory identified the mutated genes in those plants (which she called det1 mutants), and then set about analyzing their molecular pathway. Her findings were published in the journal Cell in 1989, a year after she joined the faculty of the Salk Institute for Biological Studies in La Jolla, Calif.

Many molecular plant biologists remained skeptical that a single genetic flaw could interfere with a plant’s complex response to light, but Chory persisted with her research. “I just kept at it,” she says. A series of remarkable findings followed. In 1996, her lab reported the discovery of an entirely new class of plant hormones — brassinosteroids — that are central to how plants respond to light. “Everyone was shocked that plants use steroids for hormones,” says Chory. “But it’s for the same reason that we use them. It beefs them up, makes them bigger.” Chory also made the unexpected finding that brassinosteroids don’t need to enter cells to affect plant growth, but can act through receptors on the outer surfaces of cells —  the first confirmed steroid receptor in plants. Her lab then went on to describe the entire brassinosteroid signaling pathway, from the receptor to its target genes. But brassinosteroids have not been the only focus of Chory’s work. For example, in a entirely different series of studies, Chory uncovered numerous novel findings regarding the biosynthesis and mode of action of auxin, a hormone that promotes plant stem and root growth in addition to other activities. Her lab has also pioneered the use of genetic analysis to assign functions to each of more than a dozen plant photoreceptors, which are used by plants to adapt quickly when their environment alters. More recently, Chory joined other plant biologists at the Salk Institute to launch the Harnessing Plants Initiative, which has the goal of developing plants that are more efficient at capturing and storing carbon to help tackle global warming. 

Chory’s work has transformed our molecular and genetic understanding of how plants respond to changes in their environment — findings that have profound implications for other organisms and for the fields of agriculture, environmental science, and human health. She continues to pursue this research at the Salk Institute for Biological Studies, where she is the Howard H. and Maryam R. Newman Chair in Plant Biology and director of the Plant Biology Laboratory. She is also an adjunct professor of biology at the University of California, San Diego. Chory has received numerous honors and awards for her work, including memberships in the National Academy of Sciences and the American Academy of Arts and Sciences. She is also a foreign member of the Royal Society and the German National Academy of Sciences, as well as a foreign affiliate of the French Academy of Sciences. She lives in the San Diego area with her husband, Stephen Worland. They have two grown children — a daughter, Katie, and a son, Joe.