Plant stresses such as pest infestations, disease, drought, flood, and excessive temperatures can lead to significant losses of crops each year. There is a continuing need to develop novel plant varieties that are less susceptible to damage or loss by such stresses. The present invention provides for the isolation, characterization and use of an entirely novel class of plant genes, generally designated ROB5. Transgenic plants expressing ROB5 can show a dramatic improvement in their capacity to tolerate a variety of stress conditions. Moreover, ROB5 expression can further lead to marked increases in plant growth rates and plant vigor. The present invention encompasses all such ROB5 genes and peptides encoded thereby, plants expressing corresponding ROB5 constructs, and plant products thereof.