Glycosyltransferase (GT) enzymes are the members of a large multigene family in plants that can transfer activated sugar molecules to an extensive range of acceptors, such as sterols and secondary metabolites. This glycosylation of plant metabolites helps in the fortifying defense of the plant against different environmental stress. Sterol glycosyltransferase (SGT) is a key member of GT family mainly involved in glycosylation of sterols. Previous report has shown that expression profiling of the WssgtL3.1 gene of Withania somnifera increased dramatically under diverse abiotic and biotic stress. Therefore, the present study aimed to heterologously overexpressed WssgtL3.1 gene in Arabidopsis thaliana to study its role in the mitigation of the adverse effect of Pseudomonas syringae infection. In overexpressing lines, upon pathogen infection, less bacterial growth was observed which might be due to enrichment in SA content. In addition, higher PR1 gene expression, less callose formation, less hydrogen peroxide (H₂O₂) accumulation, low MDA formation, higher SOD enzyme activity, and greater Fv/Fm were observed in all transgenic lines. Moreover, changes in glycosylation of sterols were observed in all samples; as a result, total sterol content was also found to be higher in each overexpression line. Furthermore, increased expression of squalene synthase (SQS) suggested more sterol biosynthesis in each overexpression lines due to the modulation of SA. Overall, these results suggested that high proportions of free and conjugated sterol contents in transgenic lines due to overexpression of WssgtL3.1 plays a significant role in the enhancement of immunity against P. syringae in A. thaliana plants.

糖基转移酶 (GT) 酶是植物中大型多基因家族的成员，可以将活化的糖分子转移到广泛的受体，例如甾醇和次级代谢物。植物代谢物的这种糖基化有助于加强植物对不同环境压力的防御。甾醇糖基转移酶（SGT）是 GT 家族的关键成员，主要参与甾醇的糖基化。先前的报告表明，睡茄WssgtL3.1基因的表达谱在不同的非生物和生物胁迫下显着增加。因此，本研究旨在在拟南芥中异源过表达WssgtL3.1基因。研究其在减轻丁香假单胞菌感染的不利影响中的作用。在过表达株系中，病原体感染后，观察到较少的细菌生长，这可能是由于 SA 含量的富集。此外，更高的PR1基因表达，更少的胼胝质形成，更少的过氧化氢（H ₂ O ₂) 积累、低 MDA 形成、更高的 SOD 酶活性和更大的 Fv/Fm 在所有转基因品系中观察到。此外，在所有样品中都观察到甾醇糖基化的变化；结果，还发现每个过表达品系的总甾醇含量更高。此外，由于 SA 的调节，角鲨烯合酶 (SQS) 的表达增加表明每个过表达系中更多的甾醇生物合成。总的来说，这些结果表明，在转基因株系自由和共轭甾醇含量由于过度高比例WssgtL3.1在防止免疫力的增强一个显著的作用丁香假单胞菌在拟南芥植物。