By Jules Bernstein
UC Riverside researchers have identified a mechanism that allows plants to rapidly slow growth in response to extreme environmental stress. The finding could help farmers grow more resilient crops, and one researcher continued the work years into retirement to uncover it.
The rapid response system is based on a process inside plant cells that produces compounds needed for growth, development, and survival. If even one of the key enzymes in this process fails, the plant cannot live.
Under stress conditions such as intense light, this biological pathway behaves in an unexpected manner. Rather than being governed by changes in gene expression, a standard mechanism in biology, it is modulated instantly through direct alterations in enzyme activity.
In most living things, cells adjust their RNA levels to alter protein production, which then changes the balance of other important molecules. But this process takes time that plants may not have when faced with sudden light or heat stress.
In plants, the response is much faster. Stress directly alters the activity of enzymes already present in the cell, allowing leaves to respond immediately without waiting for new proteins to be made.“This kind of response has to be immediate,” said Katie Dehesh, UCR distinguished professor of molecular biochemistry. “Changing gene expression takes time, but modifying enzyme activity allows the plant to react right away and survive.”
Source : ucr.edu