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HomeNaturebiologist who discovered the genetic origin of light-induced plant growth

biologist who discovered the genetic origin of light-induced plant growth

Portrait of Joanne Chory outside, holding onto a tree's trunk.

Credit: Salk Institute

Joanne Chory was a pioneering biologist and geneticist whose work transformed modern molecular plant biology. Her early discoveries on how plants sense and respond to light, and how they regulate growth through steroid hormones, reshaped our understanding of plant development. Her vision for using plants to mitigate global warming through carbon sequestration cemented her legacy as a scientist and innovator. Known for her fierce determination, intellectual fearlessness and generous warmth, Chory, who has died aged 69, lived with Parkinson’s disease for 20 years while continuing to dedicate her career to science and humanity.

In 2017, she co-founded the Harnessing Plants Initiative, bringing together plant biologists at the Salk Institute for Biological Studies in La Jolla, California, to develop crops capable of durably storing carbon in the soil through enhanced root systems. She saw this ‘Salk Ideal Plants’ technology as a scalable and timely solution to help to combat climate change. Her vision, showcased on-stage during the award ceremony of her Breakthrough Prize in Life Sciences in 2018 and then in her TED talk in 2019, convinced philanthropists to support a thriving research programme that spans the laboratory and the field.

Born in Boston, Massachusetts, to Lebanese immigrant parents, Chory grew up in nearby North Andover in a lively household with five siblings, four of them brothers. She credited her upbringing with preparing her for the challenges she faced in the male-dominated world of science. Her interest in biology became a passion at Oberlin College, Ohio, and led to a PhD in microbiology at the University of Illinois Urbana–Champaign. Inspired by several pioneering papers, she recognized the field’s potential and pursued a postdoctoral fellowship in plant molecular biology at Harvard Medical School in Cambridge, Massachusetts.

Exploring the genetic basis of plants’ responses to environmental factors such as light, she created mutants of thale cress (Arabidopsis thaliana) — the model organism favoured by plant geneticists. She grew them in the dark, screening for unusual individuals. Most seedlings were lanky, pale and grew only seed leaves (cotyledons), but some mutants developed adult leaves and other traits typical of light-grown plants. She named these det mutants, for ‘de-etiolated’. She discovered that the switch between growth under soil and growth in light is regulated by specific genes. When Chory published her findings in 1989, just one year after joining the Salk faculty, many were sceptical that a single gene could bypass the light requirement for normal plant development (J. Chory et al. Cell. 58, 991–999; 1989). Chory remained confident in the strength of her genetic data, and was proved correct.

She studied several det mutants and uncovered key genes and molecular mechanisms related to light responses. Among these, she found a mutation in a gene (det2) involved in the biosynthesis of brassinosteroids — plant hormones that influence development and productivity. Chory revealed that growth-regulating hormones of this family act through a receptor on the cell surface, making it the first steroid receptor to be identified outside animals. With a programme that encompassed genetics, genomics, cell biology, X-ray crystallography, biochemistry and evolutionary approaches, her lab mapped most of the brassinosteroid signalling pathway, offering a comprehensive understanding of how these hormones regulate plant development.

Chory also gained substantial insights into another plant growth hormone, auxin, and how photoreceptors enable plants to sense and respond to environmental cues.

Chory was key to developing the Salk Plant Biology Laboratory — where she rose to full professor and lab director in 1998 — into a global hub of modern plant biology. At the Harnessing Plants Initiative, she and her colleagues worked on identifying genes and molecular mechanisms for carbon-sequestration purposes, for example by altering the mass, depth and chemical composition of roots.

Driven by the desire to promote practical change in the world, in 2022, Chory co-founded the biotechnology company Cquesta, which aims to bring carbon-sequestration traits, originally identified in Arabidopsis, into high-yield, widespread crop varieties. Gene-edited commercial crop lines have shown improved root systems, with some currently progressing through field testing.

Chory’s mentorship inspired generations of scientists, particularly women, to challenge conventions and explore uncharted territory, being a founding faculty member of Salk’s Women & Science programme in 2012. She was known for her collaborative spirit, intellectual rigour and ability to inspire both her immediate colleagues and the broader scientific community. Her style of working combined a fearless pursuit of answers to challenging questions with a deep respect for her peers and mentees, creating an environment in which discourse and innovation flourished. In this spirit, Chory’s lab meetings often turned into lively discussions and vigorous debates. Chory was highly personable, with a remarkable and often self-deprecating sense of humour. In her widely viewed TED talk, she joked that she, like most scientists, would rather google a person than meet them.

Joanne Chory’s legacy lives on through her groundbreaking scientific achievements and her vision for a sustainable future. Her ideas continue to shape plant biology and inspire global efforts to address humanity’s greatest challenges. All who met her encountered a shining example of resilience, brilliance and how science could be used to promote change.

Competing Interests

The author declares no competing interests.

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