The Salk researchers, led by Joanne Chory, a professor in the Plant Molecular and Cellular Biology Laboratory and a Howard Hughes Medical Institute investigator, published their findings in this week's journal Nature.
"The steroid hormone brassinolide is central to plants' growth. Without it, plants remain extreme dwarfs. If we are going to understand how plants grow, we need to understand the response pathway to this hormone," says Chory. "This study clarifies what's going on downstream in the nucleus when brassinolide signals a plant cell to grow."
Brassinolide, a member of a family of plant hormones known as brassinosteroids, is a key element of plants' response to light, enabling them to adjust growth to reach light or strengthen stems. Exploiting its potent growth-promoting properties could increase crop yields or enable growers to make plants more resistant to drought, pathogens, and cold weather.
Unfortunately, synthesizing brassinosteroids in the lab is complicated and expensive. But understanding how plant steroids work at the molecular level may one day lead to cheap and simple ways to bulk up crop harvests.
Likewise, since low brassinolide levels are associated with dwarfism, manipulating hormone levels during dormant seasons may allow growers to control the height of grasses, trees or other plants, thereby eliminating the need to constantly manicure gardens.
Based on earlier studies, the Salk researchers had developed a model that explained what happens inside a plant cell when brassinolide signals a plant cell to start growing.
But a model is just a model. Often evi