Peroxidase 4-Based Enzymatic Synthesis of Stilbene Oligomers in Methyl Jasmonate-Elicited Grapevine Cell Suspensions

Stilbenes are specialized metabolites that are particularly abundant in <i>Vitis</i> species. Although the biosynthetic pathways of stilbenes have been well-characterized, the role of specific peroxidases in stilbene oligomerization remains to be investigated. In this study, we used grapevine cell cultures to characterize the functional role of <i>Vitis vinifera</i> peroxidase 4 (VvPRX4) in the production of resveratrol oligomers after elicitation with methyl jasmonate (MeJA). We showed that MeJA triggers the accumulation of <i>t</i>-resveratrol, resveratrol dimers, and predicted resveratrol trimers in culture medium. This accumulation was correlated with upregulation of the <i>PRX4</i> gene in grapevine cells. Using bacterial crude extracts containing VvPRX4, we demonstrated that VvPRX4 converts <i>t</i>-resveratrol into dimers, <i>t</i>-ε-viniferin into tetramers, and both combined substrates into resveratrol trimers. Additionally, VvPRX4 mediates the formation of glycosylated dimers using <i>t</i>-piceid and <i>t</i>-resveratrol as substrates. These results highlight the functional role of VvPRX4 in stilbene oligomerization in MeJA-elicited grapevine cell cultures.