Extracellular matrix and pattern in plant embryos: on the lookout for developmental information.

Cells of early plant embryos are totipotent yet follow different predetermined developmental pathways, producing embryos with well-defined autonomously developing tissues. Evidence is accumulating from a few model systems that information maintaining the determined state of a particular cell type is contained in a position-dependent manner in the extracellular matrix. This information can be released to signal back to the cell, thus controlling patterns of gene expression and influencing cell fate.