As an inquiry to explore possible plant homologues of arylalkylamine N-acetyltransferases (AANATs), a group of novel GNAT-type acetyltransferases was identified by bioinformatic analysis. The presence of highly conserved domains within the catalytic core of the predicted enzymes strongly suggests that their-encoding plant genes can be assigned to members of the GNAT superfamily. Results from DNA sequence analyses suggest that these highly conserved plant genes would unlikely to fit in the group of AANATs. In silico analysis further revealed that these novel GNATs are unique to plant systems and are conserved among widely divergent plant species, suggesting they may function in specific features unique to plant cells. Based on this bioinformatics study, a couple of characteristics were predicted or projected for these novel plant GNAT enzymes and their encoding genes, and their specific biochemical and cellular functions in plant cells. The information, we believe, may warrant future studies using molecular biology and transgenic plant approaches.