The cytoskeleton in plant cell growth: lessons from root hairs

In this review, we compare expansion of intercalary growing cells, in which growth takes place over a large surface, and root hairs, where expansion o ccurs at the tip only. Research that pinpoints the role of the cytoskeleton and the cytoplasmic free calcium in both root hairs and intercalary growin g cells is reviewed. From the results of that research, we suggest experime nts to be carried out on intercalary growing cells to test our hypotheses o n plant cell expansion. Our main hypothesis is that instability of the cort ical actin cytoskeleton determines the location where expansion takes place and the amount of expansion.