Sorbitol dehydrogenase is a cytosolic protein required for sorbitol metabolism in Arabidopsis thaliana

► Rosaceae species have abundant sorbitol dehydrogenase (SDH). ► Arabidopsis also possesses an SDH enzyme, which is cytosolic. ► SDH prefers sorbitol, ribitol and xylitol to other sugar alcohols. ► sdh- mutants have reduced growth on sorbitol and enhanced drought resistance.