Professor Dr Joanne Chory (✝︎)

Major Scientific Interests: Adaptation processes, plant growth, genetic diversity, natural variations, light conditions, shade avoidance syndrome, plant biology, climate change, growth hormone auxin, phytochromes, brassinosteroids
Joanne Chory was an American plant biologist whose work has contributed to the identification of plant hormones. She investigated the natural variations of a given plant type as well as the ways in which plants react to different light and temperature conditions.
Individuals of one and the same type of plant can often thrive in very different environmental conditions. A popular model organism of plant genetics, thale cress (Arabidopsis thaliana), grows in many parts of the world, from Northern Scandinavia to Central Africa. Joanne Chory's team examined the genetic material of this plant to find molecular clues about these adaptation processes. They also investigated the natural variations of this plant. Her laboratory contributed significantly to the decoding of three important plant hormones. She was thus able to shed light on the hitherto unknown process with which plants produce the important growth hormone auxin.
Using the example of thale cress, she also described shade avoidance syndrome. Photosensitive proteins in plants, known as phytochromes, constantly measure the environmental light conditions. If a given plant is placed somewhere too cramped and shady, processes are activated which allow it to shoot upwards. Using gene analyses, Joanne Chory and her team succeeded in localising growth genes responsible for shade avoidance syndrome. She discovered that plants’ reactions to light conditions are controlled by genetic variations. These variations ensure that plants in more northern countries react more sensitively to light than plants at the equator. Her analyses also showed that the reactions to light conditions were not subject to linear signal transmission, but rather a process with a range of interacting components.
Her laboratory was also able to decode the molecular signal chain of hormones involved in the blossoming of plants. Brassinosteroids influence gene activity controlling both plant growth and the process of cell ageing.