Polynucleotides incorporated into expression vectors have been introduced into plants and were ectopically expressed. The encoded polypeptides of the invention have been shown to confer at least one regulatory activity and confer greater size, greater organ size, greater biomass, greater yield, curlier leaves, darker coloration, greater tolerance to water deprivation, delayed flowering, delayed development, delayed senescence, greater tolerance to cold, and/or greater tolerance to hyperosmotic stress as compared to a control plant.