"Before you read this paper"

A key question in developmental biology is how cells exchange positional information for proper patterning during organ development. In plant roots, crosstalk between two adjacent cell types mediated by cell to cell movement of transcriptional factors and microRNAs is essential for patenting of vasculatures. In this lecture, we will read the following paper and learn the basic principle of plant developmental regulation through cell to cell communications as well as a unique feature of plant gene regulation through miRNA.