Ectopic Vascular Induction in Arabidopsis Cotyledons for Sequential Analysis of Phloem Differentiation

Vascular system is vital for the transport of water and nutrients as well as for providing mechanical support in many land plants. Plant transcription factors play a central role in regulating vascular development downstream of hormones and peptide signaling pathways. Particularly, cell culture systems have contributed to isolating such key transcription factors for xylem differentiation. However, there had been no efficient systems that can mimic phloem differentiation in the model plant Arabidopsis, preventing the identification of phloem-related transcription factors. We have recently established Vascular cell Induction culture System Using Arabidopsis Leaves (VISUAL), which concomitantly generates both xylem and phloem cells in the cotyledon of Arabidopsis. This system can be used to take a closer look at the bi-directional differentiation mechanism of (pro)cambial cells into xylem and phloem cells. Here, we report the methods of microscopic, genetic, and molecular analysis using VISUAL, which can help in decrypting the transcriptional networks that regulate vascular cell differentiation.