Gene expression analysis of shoot apical meristem cell types.

Shoot apical meristems (SAMs) of higher plants harbor a set of stem-cells and provide cells for the development of all the above-ground biomass of plants. Most of the important pattern formation events such as maintenance of stem-cell identity, specification and differentiation of leaf/flower primordia, and temporal control of the transition from vegetative to reproductive program are determined in SAMs. Genetic analysis has revealed molecular and hormonal pathways involved in stem-cell maintenance, organ differentiation, and flowering time. However, limited information is available as to how different pathways interact with each other to function as a network in specifying different cell types and their function. Deciphering gene networks that underlie cell fate transitions requires new approaches aimed at assaying genome-scale expression patterns of genes at a single cell-type resolution. Here we provide details of experimental methods involved in protoplasting of SAM cells, generating cell type-specific gene expression profiles, and analysis platforms for identifying and inferring gene networks.