The Use of a Photoactivatable Kaempferol Analogue to Probe the Role of Flavonol 3-O-Galactosyltransferase in Pollen Germination
- 388 Downloads
Flavonol induced pollen germination in petunia is rapid, specific, and achieved at low concentrations of kaempferol or quercetin. To determine the macromolecules that interact with the flavonol signal we have synthesized affinity-tagged kaempferol analogues. The first generation molecules are based on a benzophenone photophore. We find that 2-(3-benzoylphenyl)-3,5,7-trihydroxychromen-4-one (BPKae) antagonizes flavonol-induced pollen germination in a concentration-dependent manner. Further, BPKae acts as an irreversible inhibitor of flavonol 3-O-galactosyltransferase (F3GalTase), the gametophyte-specific enzyme that controls the accumulation of glycosylated flavonols in pollen. The effects of BPKae are mediated by UV-A light treatment. The binding characteristics of BPKae to F3GalTase suggest that it can be used to identify the residues required for flavonol-binding and catalysis.
KeywordsTube Growth Pollen Germination Flavonol Glycoside Affinity Probe Bioactive Small Molecule
Unable to display preview. Download preview PDF.
- Chowdhry, V., and Westheimer, F. H., 1979, Photoaffinity labeling of biological systems, Ann. Rev. Biochem. 48: 293325.Google Scholar
- Ishikura, N., and Mato, M., 1993, Partial purification and some properties of flavonol 3-O-glycosyltransferases from seedlings of Vigna mungo with special reference to the formation of kaempferol-3-O-galactoside and the 3–0-glucoside, Plant Cell Physiol. 34: 329–335.Google Scholar
- Miller, K. D., Guyon, V., Evans, J. N. S., Shuttleworth, W. A., and Taylor, L. P., 1999, Purification, cloning, and heterologous expression of a catalytically efficient flavonol 3-O-galactosyltransferase expressed in the male gametophyte of Petunia hybrida, J. Biol. Chem. 274: 34011–34019.CrossRefGoogle Scholar
- Pollak, P. E., Vogt, T., Mo, Y., and Taylor, L. P., 1993, Chalcone synthase and flavonol accumulation in stigmas and anthers of Petunia hybrida, Plant Physiol. 102: 925–932.Google Scholar
- Taylor, L. P., and Jorgensen, R., 1992, Conditional male fertility in chalcone synthase-deficient petunia, J. of Hered. 83: 11–17.Google Scholar
- Vogt, T., Zimmermann, E., Grimm, R., Meyer, M., and Strack, D., 1997, Are the characteristic of betanidin glucosyltransferases from cell-suspension cultures of Dorotheanthus bellidiformis indicative of their phylogenic relationship with flavonoid glucosyltransferases? Planta 203: 349–361.CrossRefGoogle Scholar
- Woo, H.-H., Orbach, M. J., Hirsch, A. M., and Hawes, M. C., 1999, Meristem localized inducible expression ofa UDP-glycosyltransferase gene is essential for growth and development in pea and alfalfa, Plant Cell 11:2303–2315.Google Scholar