Drought-tolerant crops are one step closer to becoming reality.
Scientists at The Medical College of Wisconsin and the University of California, Riverside say they now have a better understanding of the synthetic chemical pyrabactin, paving the way for the development of more effective chemicals to help plants resist drought.
Their work builds on the breakthrough discovery of the chemical in 2009 by UC Riverside professor Sean Cutler.
Pyrabactin mimics a natural stress hormone found in plants called abscisic acid, or ABA, that helps them cope with adverse conditions. Normally, it's produced in modest amounts, and inhibits growth, thus reducing the amount of water a plant requires.
ABA has already been commercialized for agricultural use (corn, soybeans, etc.), but it has two primary disadvantages: it's light-sensitive, and expensive to produce.
Pyrabactin was a breakthrough because it's simple and relatively inexpensive to make. It's also not sensitive to light. It does have one drawback, however: it's less effective than ABA, and does not activate all the plant's protein receptors necessary for complete drought-tolerance. (If you're trying to imagine this, think about how enzymes work: the key has to fit the hole, no matter how subtle the differences.)
Consider it a fine example of nature's supremacy over man's attempts in the lab.
The researchers performed genetic experiments that helped them pinpoint which amino acids in the plant's protein receptors are critical for determining the effectiveness of pyrabactin. They also identified why certain receptors were more sensitive to the chemical than others.
In this case, knowledge is power, and understanding why pyrabactin is less effective than ABA at the molecular level is the first step in learning how to manufacture more efficient chemicals, the scientists said.
Their research was published in the journal Nature Structural & Molecular Biology.
Photo, top: Sean Cutler. (UCR Strategic Communications)