Abstract
Auxin is an essential regulator for almost every aspect of plant growth and development. Our research focuses on the molecular mechanisms of how auxin regulates plant growth and development, particularly organogenesis. Genetic screens for mutants with altered responses to exogenous auxin have led to major breakthroughs in auxin biology. We approached the key questions in auxin biology from the other end of the auxin spectrum by analyzing partially auxin deficient mutants. We have demonstrated that the YUC family of flavin monooxygeanses catalyzes a rate-limiting step in auxin biosynthesis. We have shown that YUC-mediated auxin biosynthesis is essential for all major developmental events. We conducted large-scale genetic screens for mutants that fail to make flowers in the auxin biosynthetic yuc mutant backgrounds, but not in a wild type background. Analyses of the mutants have led to the discovery of a major new pathway through which auxin regulates plant organogenesis. We further showed that this new pathway for auxin-regulated organogenesis is analogous to the pathway used in blue-light mediated phototropic bending and gravity-mediated directional root growth.
