Abstract: A nucleic acid having (i) a DNA molecule which, when expressed in a plant or plant cell, increases the trehalose content of the plant or plant cell, the DNA molecule encoding an E. coli trehalose phosphate synthase, and (ii) a plant expressible promoter operatively coupled to the DNA molecule. Also, a method for obtaining a plant with increased trehalose production by introducing into a recipient cell of a plant, a plant expressible gene which, when expressed in a plant or plant cell increases the trehalose content of the plant or plant cell. The plant expressible gene is an E. coli trehalose phosphate synthase gene which is operably linked to: a) a transcriptional initiation region that is functional in the plant, and b) a DNA molecule encoding a selectable marker gene that is functional in the plant. The method includes a step of regenerating a plant from the recipient cell under conditions that allow for selection for the presence of the selectable marker gene.