| Abstract: | At the time of writing it is 10 years since the first putativeauxin receptor was purified, the auxin-binding protein of maizeseedlings (ABP1). Over these 10 years an enormous amount ofwork has been done to try and confirm that this protein is areceptor. Much of the effort has been in gathering descriptiveinformation about the protein (its chemistry and its activesites), the genes encoding it (gene structure, promoter analysis)and the sites at which it is expressed. This information, andthe probes generated during these investigations, have beenput to use in functional assays to try to find out more directlywhat role ABP1 plays in auxin responsiveness. The key to defininga receptor is the suitability of the assay used to report onreceptor occupancy and the choice of assays available for auxinsis discussed in this review. It is shown how the various approacheshave developed to complement each other and what they have toldus about ABP1, but there are still some enigmas in the ABP1story. Some problems appear to have been resolved, but morequestions remain than have been answered and some of the waysin which these problems are being tackled are discussed. Key words: Auxin, receptor, protoplasts, antibodies, Zea mays L |
