Transient gene expression in petunia flower petals as a toolbox

Agroinfiltration-mediated transient expression is widely used in plant gene functional studies. In this study, the functionality of a metabolic engineering construct containing multiple expression cassettes for betalain biosynthesis genes was validated via agroinfiltration in petunia flower petals. The effects of transcription factors that upregulate anthocyanin biosynthesis and a gene that regulates cellular pH were also demonstrated on petunia petals by agroinfiltration. We also showed that flower petal agroinfiltration is a quick approach to test gene editing components, e.g. different guide RNAs. In general, the agroinfiltration-mediated transient transformation in flower petals is a great tool for testing flowering colour-related trait genes, as well as for optimising gene editing components.