Several dwarf mutants and gibberellin (GA) responsive and unresponsive mutants have been produced and collected. Some of these mutants appear to be defective in their production of the active GA, while others are either unresponsive to exogenously applied GA, or are hyper-responsive to endogenous GA. The mutants are being crossed to produce combinations of different gibberellin synthesis and responsiveness. The combined mutant stocks, along with exogenous GA and anti-GA growth regulators, will be used to further illuminate the role(s) of GA in plant growth, stress response, and enzyme synthesis. The combinations that will be created will provide a unique tool for studying the relationships among specific, defined GAs, both endogenously and exogenously. The results of these studies should be applicable to any plant species as the GAs are a central, critical hormonal system common to all flowering plants.