Discovery of the salicylic acid-binding protein 2 (SABP2) gene, by scientists at Boyce Thompson Institute for Plant Research (BTI) at Cornell University, is being called an important step toward new strategies to boost plants' natural defenses against disease and for reducing the need for agricultural pesticides.
Salicylic acid, the chemical compound found naturally in most plants (as well as in the most-used medication, aspirin), is a plant hormone produced at elevated levels in response to attack by microbial pathogens. According to a report on the Web today in the Proceedings of the National Academy of Sciences (PNAS Early Edition, week of Dec. 7, 2003) by BTI's Dhirendra Kumar and Daniel F. Klessig, the aspirin-like hormone is perceived by the SABP2 protein and a message is transmitted, via a lipid-based signal, to activate the plant's defense arsenal. Says Klessig, "Now that we know a key signaling protein in plant immune systems, we can work on ways to enhance the signal and help plants fight disease without using potentially harmful pesticides."
The PNAS authors say SABP2 plays an important role in restricting infections by inducing host cells at the site of infection to undergo programmed cell death and sacrifice themselves for the benefit of the rest of the plant.
SABP2 also plays a critical role in activating the innate immune system in other parts of the plant to guard against further attack or spread by the same pathogen and even against unrelated pathogens. (Innate immune systems, which mount an immediate defense against infections, are found in all plants and animals. But only vertebrates, including humans and other mammals, have additional levels of defense the antibody-producing B cell and T cell-mediated acquired immunity for a dela
Contact: Roger Segelken
Cornell University News Service