Abstract

Sterol glycosylation, facilitated by sterol UDP-glycosyltransferases (SGTs), plays a crucial role in various biological functions, influencing cellular homeostasis, lipid metabolism, water solubility, molecule stability, and the properties of cell membranes for improved transport system access and stress tolerance. In the model plant Arabidopsis thaliana (A. thaliana), two sterol β-glucosyltransferase genes within the UGT80 subfamily, UGT80B1 (At1g43620) and UGT80A2 (At3g07020), are responsible for catalyzing the glycosylation of the 3β-hydroxy group of sterols, resulting in the formation of 3β-D-glycosides.Analysis of knockout mutants for both genes, particularly salk-021175 (Atg43620 gene), revealed a moderate impact on growth under normal conditions, with a distinctive transparent seed coat compared to other genotypes. However, under salt stress, this knockout mutant exhibited significant adverse effects on overall plant growth, physiological activities, and enzyme functions compared to other genotypes. The relative expression of AtSGTs under salt stress, along with chlorophyll fluorescence analysis, emphasized the crucial role of the Atg43620 gene in both normal plant growth and stress responses. Overall, the findings underscore the importance of sterol glycosylation, particularly mediated by the Atg43620 gene, in shaping plant physiology and enhancing stress tolerance.

Description