The Search for ABA Receptors Continues

In 2006, a paper ‘made a splash’ in the plant biology world by identifying the elusive protein receptor of the phytohormone abscisic acid (ABA). The paper, published by the prestigious journal Nature, showed that FCA - an RNA binding protein involved in flowering - binds to ABA with high affinity. The study has been cited 120 times, and is the most highly cited paper among the 95 results for 'abscisic acid receptor' in the past three years. Nature is now retracting the paper after reports that the work could not be replicated.

ABA regulates various physiological processes such as stomatal closure, bud dormancy and seed germination. Being a stress hormone, ABA is a target for scientists hoping to develop drought and salinity-tolerant crops. Identification of ABA receptors will significantly advance the development of stress-proof plants and the retraction is a setback in the search to find ABA targets.

Two other ABA receptors have been reported, the plastid-associated Mg-cheltase H subunit and a protein originally identified as a membrane-bound G-protein-coupled receptor 2, using methods similar to those used in the retracted paper. Scientists now question the role of these proteins as ABA receptors.

Read the summary article at http://dx.doi.org/10.1038/456683a The original (retracted) paper can be downloaded at http://dx.doi.org/10.1038/nature04373 and the paper questioning this study is available at http://dx.doi.org/10.1038/nature07646