A team of University of Manitoba plant scientists is the first in the world to discover a receptor for a plant hormone called abscisic acid (ABA). The discovery, published in the January 19, 2006 edition of the scientific journal Nature, represents a major leap forward in our understanding of plant growth and development.

“ABA is essentially a survival hormone that is involved in a plant’s response to many environmental stresses,” said principal investigator Robert Hill, plant science. “The hormone is particularly important for plant survival in our Canadian climate where the response to cold, drought, salt and the timing of germination and flowering are all regulated by this hormone.”

The team has found that a protein called FCA, involved in the plant’s transition from a juvenile to a reproductive stage, is a receptor for ABA. While scientists have known about ABA for many years, nobody had previously been able to isolate a receptor site for the hormone. The discovery of this ABA receptor is a key component in understanding how plants acclimate to environmental stress. The findings are of particular significance to agriculture and forestry.

Hill, along with postdoctoral fellows Fawzi Razem and Ashraf El-Kereamy, collaborated on the project with Suzanne Abrams from the National Research Council Plant Biotechnology Institute in Saskatoon and researchers in the UK.

The paper in Nature describes the steps involved in the discovery by Hill and his team that FCA is an ABA receptor. It provides proof that FCA binds ABA and that this binding has an effect on the action of the protein at the molecular, cellular and whole plant level.

“The downstream actions of ABA have been known for many years” Hill said. “This is the first description of the receptor part of the process. We were standing with a key at a door, knowing what was happening on the other side, but unable to find the lock. We have now found the lock.”