Laser Microdissection of Plant Cells - Plant Cell Morphogenesis: Methods and Protocols - page 239

Chapter 21

Laser Microdissection of Plant Cells

Yvonne Ludwig and Frank Hochholdinger

Abstract

Different plant cell types express unique transcriptomes, proteomes, and metabolomes. Therefore, the
isolation of specifi c cell types prior to molecular analyses is important to understand the specifi cation,
differentiation, and function of these cells. Isolation of specifi c plant cell types from composite organs can
be achieved by laser microdissection (LMD). A wide variety of methods to fi x and embed tissues prior to
LMD and downstream molecular analyses have been developed for different plant species and tissues. The
present review summarizes and highlights the most recently applied LMD approaches in plant science.

Key words Laser microdissection, Plant, Cell type, Sectioning, Fixation, Embedding

1 Introduction

All cells of a plant contain the same nuclear genome. However,
each cell type expresses a unique subset of these genes at a specifi c
developmental stage or environmental condition. The set of active
genes refl ects the status of a cell type with respect to specifi cation,
differentiation, and functionality. Therefore, the subset of all bio-
molecules such as transcripts, proteins, and metabolites expressed
by a specifi c cell widely varies between different cell types of a
plant. Due to these cell-type-specifi c expression variations, moni-
toring gene activity in composite plant tissues or organs masks
individual expression profi les of specifi c cells because such surveys
integrate expression over all cell types [ 1 ]. This is in particular a
problem when a specifi c cell type represents only a small fraction of
all cells of an organ. For instance, pericycle cells, which divide and
give rise to lateral roots, are estimated to constitute <1 % of all root
cells in maize [ 2 ]. Therefore, monitoring gene expression profi les
in such specifi c cells is important to better understand their speci-
fi cation, differentiation, and function [ 3 ]. To study specifi c cell
types from composite tissues in more detail requires separating
them from other cells to reduce contamination to a minimum.