Identification and Characterization of Abiotic Stress Induced  novel UDP-Glucosyltransferase (UGT72L11) Gene from Glycyrrhiza glabra L.

The present study reports a unique broad spectrum UDP-glycosyltransferase from Glycyrrhiza glabra involved in multiple stress responses and abscisic acid mediated glycosylation. The identified UGT72L11 gene was cytoplasmic with ORF of 1425 bp encoding a 52.2 kDa protein of 474 amino acids. Phylogenetic analysis revealed maximum homology (73.3%) with epicatechin 3-glucosyltransferase (ACC38470) from Medicago truncatula exhibiting sequence uniqueness. The gene was differentially expressed in shoot tissues and significantly upregulated in abscisic acid treatment (122.3 folds) and under cold stress (36 folds) in planta . In-silico Structure-Activity-Relationship revealed GLU279, ARG386, PRO380 and TRP379 residues being involved in receptor-ligand interactions. The UGT72L11 protein was optimal between 10ºC to 30ºC preferring quercetin-UDPGlc ( K _m 0.23) over kaempferol-UDPGlc ( K _m 0.47). The purified recombinant protein showed multi-substrate O-glycosylation towards various classes of aglycones, abscisic acid, and also displayed C-glycosylation with colchicine as a foundation for the future medicinal applications.