Colony formation from mesophyll protoplasts of a cereal, oat

Differentiated leaf cells of gramineous plants, among them the cereals with their immense importance for human nutrition, are considered extremely recalcitrant to, if not incapable of, reentering the cell cycle. This recalcitrance is related to the poor wound response of the monocots—in contrast to most dicots—and the difficulties encountered in monocot tissue culture. We report here the highly reproducible induction of sustained divisions at high frequency (up to 95%) and colony formation from mesophyll protoplasts of a cereal, oat, demonstrating that—contrary to most earlier evidence—mesophyll cells of a gramineous plant have not irreversibly lost their potential for cell division.