Growing drought-tolerant crops inching forward

Seed Daily: A collaborative team of scientists led by researchers at The Medical College of Wisconsin, in Milwaukee, has used the tools of structural biology to understand how a synthetic chemical mimics abscisic acid (ABA), a key stress hormone that helps plants cope with adverse environmental conditions such as drought.

…For years scientists have searched for practical ways to use ABA signaling to improve drought tolerance in agriculture. Unfortunately, the synthetic form of ABA used commercially is light sensitive and expensive. The new study builds on the earlier discovery by scientists at University of California, Riverside of pyrabactin, a synthetic chemical that mimics ABA. However, unlike ABA, pyrabactin activates only a few of the 14 ABA receptors in the plant needed for effective drought tolerance.

"By better understanding how pyrabactin works, we can develop new chemicals to enable plants to resist drought. These same chemicals that signal the response to drought may also contribute to increasing crop yields," says Francis Peterson, Ph.D., lead author and assistant professor of biochemistry at the Medical College.

An ABA receptor is a protein that functions as a molecular switch inside the cell. When an ABA molecule inserts into a cavity within the receptor, it sends a signal by changing the protein structure in a way that resembles the closing of a gate.

…"These insights suggest new strategies for modifying pyrabactin and related compounds so that they can mimic the signaling process of the naturally occurring ABA. This work has paved the way for manufacturing new molecules that activate or turn on receptors" said Sean Cutler, Ph.D., associate professor of plant cell biology at UC Riverside. "The current research is an important step on the way to what is likely to be the next big result: an ABA-mimicking chemical that can be applied to corn, soy bean and other crops," explained Dr. Peterson….

Bridleway to Clare in the UK. Wide cracks are appearing in this path across a wheat field, indicating the current drought. This bridleway is part of the Bury St Edmunds to Clare long-distance walk. Shot by Bob Jones, Wikimedia Commons via geograph.org.uk, under the Creative CommonsAttribution-Share Alike 2.0 Generic license