The present invention provides compositions and methods for modification of rhizobacteria to reduce or eliminate gibberellin production. The modified rhizobacteria are used in methods and compositions that alter the physiology of nodulating plants. These methods and compositions involve combining the modified rhizobacteria with a nodulating plant, or a seed or part thereof, or providing the modified rhizobacteria to a nodulating plant, or seed or part thereof. In another aspect, the invention involves the nodulating plants produced by these methods, wherein the nodulating plants have altered physiology as a result of association with the modified rhizobacteria.
