@article { ISI:000319134800020, title = {Functional characterization of a flavonoid glycosyltransferase gene from withania somnifera (Ashwagandha)}, journal = {Applied Biochemistry and Biotechnology}, volume = {170}, number = {3}, year = {2013}, month = {JUN}, pages = {729-741}, publisher = {HUMANA PRESS INC}, address = {999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA}, abstract = {

Glycosylation of flavonoids is mediated by family 1 uridine diphosphate (UDP)-dependent glycosyltransferases (UGTs). Until date, there are few reports on functionally characterized flavonoid glycosyltransferases from Withania somnifera. In this study, we cloned the glycosyltransferase gene from W. somnifera (UGT73A16) showing 85-92 \% homology with UGTs from other plants. UGT73A16 was expressed as a His(6)-tagged fusion protein in Escherichia coli. Several compounds, including flavonoids, were screened as potential substrates for UGT73A16. HPLC analysis and hypsochromic shift indicated that UGT73A16 transfers a glucose molecule to several different flavonoids. Based on kinetic parameters, UGT73A16 shows more catalytic efficiency towards naringenin. Here, we explored UGT73A16 of W. somnifera as whole cell catalyst in E. coli. We used flavonoids (genistein, apigenin, kaempferol, naringenin, biochanin A, and daidzein) as substrates for this study. More than 95 \% of the glucoside products were released into the medium, facilitating their isolation. Glycosylation of substrates occurred on the 7- and 3-hydroxyl group of the aglycone. UGT73A16 also displayed regiospecific glucosyl transfer activity towards 3-hydroxy flavone compound, which is the backbone of all flavonols and also for a chemically synthesized compound, not found naturally. The present study generates essential knowledge and molecular as well as biochemical tools that allow the verification of UGT73A16 in glycosylation.

}, keywords = {Flavonoid, glycosylation, Glycosyltransferase, Hypsochromic shift, Plant secondary product glycosyltransferase (PSPG), Withania somnifera}, issn = {0273-2289}, doi = {10.1007/s12010-013-0230-2}, author = {Singh, Somesh and Vishwakarma, Rishi. K. and Kumar, R. J. Santosh and Sonawane, Prashant D. and Ruby and Khan, Bashir Mohammad} } @article {50037, title = {Phenylpropanoid-specific glycosyltransferases from mango and their potential role in defense}, journal = {Plant Physiology and Biochemistry}, volume = {232}, year = {2026}, month = {MAR}, pages = {111137}, type = {Article}, abstract = {

Alphonso mango (Mangifera indica cv. Alphonso) is a cornerstone of India{\textquoteright}s fruit industry due to its distinct aroma and shelf-life characteristics. The uridine diphosphate-dependent glycosyltransferases (UGTs) play a crucial role in stabilising aroma and defense-related specialised metabolites in fruits. The present study explores the potential role of UGTs during mango ripening and Colletotrichum gloeosporioides infection. Gene expression analysis indicated that UGTs showed dynamic expression in skin and pulp during ripening. Phylogenetic analysis revealed substrate-driven divergence of UGTs, with MiUGT92A14 and MiUGT95B15 forming distinct clades associated with flavonoid glycosylation. Recombinant UGTs showed a higher preference for UDP-glucose, which is corroborated by the high accumulation of UDP-glucose during ripening. Furthermore, it was observed that MiUGT92A14 prefers phenolic acids as substrates, while MiGT95B15 shows flavonoid specificity. Spore germination assays demonstrated that both aglycones and their glycosylated derivatives suppressed early fungal morphogenesis, supporting a role for UGT-mediated glycosylation in maintaining defense-related metabolites in a bioactive yet non-toxic form during fruit ripening. Additionally, Colletotrichum gloeosporioides inhibition assays demonstrated that glycosylated products of selected UGTs exhibited equal or enhanced antifungal activity compared with their aglycone forms, indicating that glycosylation promotes the safe accumulation of antifungal compounds by reducing aglycone toxicity to the plant. These findings suggest that glycosylation of specific metabolites is a key for ripening process and to potentiate defence against fungal pathogen.

}, keywords = {Anthracnose, defense, Flavonoid, Glycoconjugates, Uridine diphosphate-dependent glycosyl-transferase}, issn = {0981-9428}, doi = {10.1016/j.plaphy.2026.111137}, author = {Vare, Tejas and Joshi, Rakesh and Liao, Jieren and Hoffmann, Thomas and Schwab, Wilfried and Giri, Ashok} } @article {50051, title = {Rootless survivors in plants}, journal = {Plant Science}, volume = {364}, year = {2026}, month = {MAR}, pages = {112951}, type = {Review}, abstract = {

The root system provides anchorage, uptakes of nutrients and water, and forms different associations within soil environments that govern plant fitness, crop performance, and yield. Auxin controls almost all aspects of root development. Both shoot- and root-derived auxins contribute to formation of polar auxin transport, which is crucial for establishing and maintaining normal root architecture. The coordinated activities of auxin influx and efflux carriers establish necessary polar auxin transport. A variety of natural metabolites and synthetic compounds are shown to interfere with auxin metabolism, transporters and signaling pathways having a negative impact on root growth. In this review, we highlight the reports demonstrating the observance of rootless phenotypes in plants and associated molecular mechanisms. Rootless phenotypes can be produced under in vitro culture conditions by modulation of phytohormone combinations (especially auxin and cytokinin), and supplementation of naturally-occurring flavonoids and their glycosides or synthetic auxin transport inhibitors (1-Nnaphthylphthalamic acid and 2,3,5-triiodobenzoic acid) or under in vivo conditions by modulation of several genes directly or indirectly associated with auxin biology. Further, we describe the crosstalk of naturallyoccurring flavonoids (e.g. kaempferol, quercetin), their glycosides, and other metabolites (e.g. azelaic acid, cis-cinnamic acid) with auxin transporters, their mobile nature, and influence on root development. Moreover, we provide evolutionary perspective on the auxin and flavonoid pathways and their possible roles in naturally rootless plants. We also emphasize the importance of rootless or reduced root growth phenotypes in modern agriculture, and the pressing needs to utilize naturally occurring auxin transport inhibitors for industrial and research applications.

}, keywords = {Auxin, Flavonoid, Flavonoid-glycoside, Polar auxin transport, rootless}, issn = {0168-9452}, doi = {10.1016/j.plantsci.2025.112951}, author = {Kondhare, Kirtikumar R. and Lavhale, Santosh G. and Giri, Ashok P.} }