Multiple modes of cell division control in Arabidopsis flower development.

Control of the pattern of cell divisions is central to plant development. Several different types of control exist: examples include control of overall cell number in floral meristems, control of relative cell numbers in floral whorls, and control of the relative spacing of the cell divisions that establish floral organs. Mutations that change each of these levels of control are described: mutations in the SUPERMAN gene affect relative amounts of cell division in adjacent floral whorls; mutations in the CLAVATA genes affect overall meristematic cell number; and mutations in PERIANTHIA affect the spacing of floral organs.