Transient gene expression in Medicago truncatula leaves via agroinfiltration

Transient expression is a powerful method for the functional characterization of genes. In this chapter, we outline a protocol for the transient expression of constructs in Medicago truncatula leaves using Agrobacterium tumefaciens infiltration. Using quantitative real-time PCR we demonstrate that the infiltration of a construct containing the LEGUME ANTHOCYANIN PRODUCTION 1 (LAP1) transcription factor results in the strong upregulation of key biosynthetic genes and the accumulation of anthocyanin pigment in the leaves after just 3 days. Thus, this method provides a rapid and powerful way to the discovery of downstream targets of M. truncatula transcription factors.