The glycosylation of nicotinate (NA), a key intermediate of the NAD salvage pathway, occurs widely in land plants. However, the physiological function of NAglycosylation is not well understood in planta, and no gene encoding NAglycosyltransferase has been reported to date. NA glycosylation in Arabidopsis thaliana occurs at either the N- or the O-position of the NA molecule, and O-glucosylation appears to be unique to the Brassicaceae. Using gene-enzyme correlations focused on Family 1 glycosyltransferases (GTs; EC 2.4), we identified and characterized three Arabidopsis GTs, which are likely involved in NAglycosylation. These include one NAOGT (UGT74F2; previously identified as a salicylic acid glycosyltransferases) and two NANGTs (UGT76C4 and UGT76C5). Arabidopsis mutants of UGT74F2 accumulate higher levels of free NA, but not salicylic acid, than that of the wild type, and this inversely correlated with seed germination rates under various abiotic stresses. The germination defect of theugt74f2-1 mutant could be fully complemented by overexpression of UGT74F2. These observations, together with comprehensive chemical analysis, suggest thatNA glycosylation may function to protect plant cells from the toxicity of NAoveraccumulation during seed germination. Combined with phylogenetic analysis, our results suggest that NAOGTs arose recently in the Brassicaceae family and may provide a fitness benefit. The multifunctionality of UGT74F2 in Arabidopsis is also investigated and discussed.