Instead, brassinosteroid perception leads to a cascade of biochemical events that alter the ability of key proteins to dimerize and activate gene expression within a cell's nucleus. In plants, there are scores of genes involved in growth and development that can be influenced by brassinosteroids, Chory noted.
"Many of these genes are predicted to be involved in growth, like cell wall metabolism. Their up-expression would be predicted to promote cell expansion," according to Chory.
The work of other groups, she noted, has shown that brassinosteroids can negatively regulate their own expression as part of a feedback loop that, ultimately, determines the size of a plant. In nature, that feedback loop has served plants well, helping them adjust their height and size to fit the growing conditions of any environmental niche.
Through traditional methods of plant breeding, humans have been manipulating plant stature for thousands of years. In recent years, through the methods of genetic engineering, more precise methods for altering industrial plant strains have come into play.
But access to a pathway used by plant hormones to dictate size promises broader influence over the many genes involved in the process of growth. Levers that could be used to alter a hormone pathway to influence plant development and stature, according to Chory, include modifying the levels of the hormone, manipulating the chemical structures of hormones, and recoding the signals sent along the pathway.