Pluripotent versus totipotent plant stem cells: dependence versus autonomy?
Little is known of the mechanisms that induce the dedifferentiation of a single somatic cell into a totipotent embryogenic cell that can either be regenerated or develop into an embryo and subsequently an entire plant. In this Opinion article, we examine the cellular, physiological and molecular similarities and differences between different plant stem cell types. We propose to extend the plant stem cell concept to include single embryogenic cells as a totipotent stem cell based on their capacity to regenerate or develop into an embryo under certain conditions. Our survey suggests that differences in chromatin structure might ensure that meristem-localized stem cells have supervised freedom and are pluripotent, and that embryogenic stem cells are unsupervised, autonomous and, hence, freely totipotent.
Verdeil
Jean-Luc
JL
Centre de Coopération Internationale en Recherche Agronomique pour le Développement, CIRAD, UMR 1096, TA 96/02, Montpellier Cedex 5, France. jean-luc.verdeil@cirad.fr <jean-luc.verdeil@cirad.fr>
Alemanno
Laurence
L
Niemenak
Nicolas
N
Tranbarger
Timothy John
TJ
D002843:Chromatin / Q000378:metabolism; D018519:Meristem / Q000166:cytology / Q000378:metabolism; D008854:Microscopy, Electron; D008954:Models, Biological; D059828:Plant Cells; D010944:Plants / Q000196:embryology / Q000378:metabolism; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D039901:Totipotent Stem Cells / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure
D002843:Chromatin