Submitted to: Phytochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/19/1996
Publication Date: N/A
Interpretive Summary: Abscisic acid (ABA) is a plant hormone that plays an important role in the response of plants to certain environmental stresses, including water shortage. ABA levels increase when plants are subjected to partial desiccation, and physiological responses to conserve water are initiated. Little is known about how ABA initiates these reponses. One possibility is that ABA binds to a specific receptor within the plant, and the binding of that receptor initiates a cascade of biochemical reactions which eventually alter the plants susceptibility to dehydration. Unfortunately, the identity of the ABA receptor is not known. This study prepared and tested a method of linking ABA to a matrix in such a way that the ABA molecul retained its natural configuration. This ABA-linked matrix was used to purify ABA-binding antibodies prepared previously. The fact that this matrix bound the antibodies in a highly specific manner suggested that it also may bind ABA receptors isolated from plant extracts. As such, it will be useful in studies to identify ABA-binding proteins that play a role in plant responses to environmental stresses.
Technical Abstract: Abscisic acid was functionalized at the 3' position by reaction of its alpha-2'3' epoxide with 1, 4-butanedithiol to afford the correspondeing derivative having a 6 atom linker arm containing a terminal sulfhydryl group. This derivative was coupled to epoxy activated sepharose 6B affording a gel containing ca 1.4 mg(+)-ABA/mL. This gel was used for the purification of an anti-ABA antibody from hybridoma culture broth and its minimum binding capacity determined. This affinity matrix will be useful in the isolation and identification of ABA-binding proteins that play a role in plant responses to environmental stresses.