A transgenic plant transformed by a pyrophosphatase stress-related protein (PPSRP) coding nucleic acid, wherein expression of the nucleic acid sequence in the plant results in increased tolerance to environmental stress as compared to a wild type variety of the plant. Also provided are agricultural products, including seeds, produced by the transgenic plants. Also provided are isolated PPSRP, and isolated nucleic acid coding PPSRP, and vectors and host cells containing the latter. Further provided are methods of producing transgenic plants expressing PPSRP, methods of identifying novel PPSRP, and methods of modifying the expression of PPSRP in plants.