IIGB scientists led by associate professor Sean Cutler have successfully engineered drought-threatened crops to respond to an agrochemical as if it were abscisic acid (ABA), a stress hormone that inhibits plant growth and reduces water consumption to assist survival during droughts.

The researchers worked with Arabidopsis, a model plant used widely in plant biology labs, and the tomato plant. In the lab, they used synthetic biological methods to develop a new version of these plants’ abscisic acid receptors, engineered to be activated by the agrochemical mandipropamid instead of ABA. The researchers showed that when the reprogrammed plants were sprayed with mandipropamid, the plants effectively survived drought conditions by turning on the abscisic acid pathway, which closed the stomata on their leaves to prevent water loss.

The finding illustrates the power of synthetic biological approaches for manipulating crops and opens new doors for crop improvement that could benefit a growing world population.

Study results appear online Feb. 4 in Nature.

Cutler explained that discovering a new chemical and then having it evaluated and approved for use is an extremely involved and expensive process that can take years. “We have, in effect, circumvented this hurdle using synthetic biology – in essence, we took something that already works in the real world and reprogrammed the plant so that the chemical could control water use,” he said.

Protein engineering is a method that enables the systematic construction of many protein variants; it also tests them for new properties. Cutler and his co-workers used protein engineering to create modified plant receptors into which mandipropamid could fit and potently cause receptor activation. The engineered receptor was introduced into Arabidopsis and tomato plants, which then responded to mandipropamid as if they were being treated by ABA. In the absence of mandipropamid, these plants showed minimal difference from plants that did not possess the engineered protein.

Cutler was joined in the research by Sang-Youl Park, Assaf Mosquna and Jin Yao at UCR; and Francis C. Peterson and Brian F. Volkman at the Medical College of Wisconsin.

UCR’s Office of Technology Commercialization has filed a patent application on the technology described in the research paper.

For additional information, please visit:

• LA Times February 4, 2015
• Press Enterprise February 5, 2015