The unique ability to perform targeted gene disruption in mosses has made Physcomitrella patens an attractive choice for plant functional genomics. A cDNA ALDH11A5 (AY504666) was identified in the plant P. patens with significant similarity to the cytosolic NADP -dependent, non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase (GAPN; EC 1.2.1.9). RNA blot hybridization was used to analyze ALDH11A5 mRNA transcript abundance in response to a variety of stresses including high osmoticum (600 mM sorbitol), salinity (300 mM NaCl), and ABA application (50 μM). This is the first report of GAPN from bryophytes, and demonstrates that this unique plant enzyme is not restricted to tracheophytes.