CELL FATE REGULATION IN THE SHOOT MERISTEM

The shoot meristem is a proliferative centre containing pluripotent st ern cells that are the ultimate source of all cells and organs continu ously added to the growing shoot. The progeny of the stem cells have t wo developmental options, either to renew the stem cell population or to leave the meristem and to differentiate, possibly according to sign als from more mature tissue. The destiny of each cell depends on ifs p osition within the dynamic shoot meristem. Genetic data suggest a simp le model in which graded positional information is provided by antagon istic gene functions and is interpreted by genes which regulate cell f ate.