ABSTRACT Virus‐induced gene silencing (VIGS) is a method that exploits plant antiviral defense mechanisms to downregulate endogenous genes. The technique is versatile, rapid, and widely used for functional genomics studies. Here, we report a method for VIGS in the medicinal plant, Calendula officinalis (pot marigold). This species produces anti‐inflammatory triterpenoids and has also been bred and cultivated as an ornamental plant. We describe a method for the injection of Agrobacterium tumefaciens cultures into leaf midribs and compare visual marker genes for tracking VIGS utilizing constructs that simultaneously target visual marker and target genes. We use these tools to demonstrate that silencing a gene encoding cycloartenol synthase results in changes to leaf phytosterols. This method could be used to further investigate the genetic basis of specialized metabolism in this species and could be adapted to other members of the Asteraceae family, many of which are of economic and chemical value.
Cuthbert et al. (2026) studied this question.