Portal de Periódicos da CAPES

Cell Cycle, Cell Expansion and Polarity During Morphogenesis of Appendicular Structures in Riella helicophylla

1983; Elsevier BV; Volume: 112; Issue: 4 Linguagem: Inglês

10.1016/s0044-328x(83)80050-6

0044-328X

Luise Stange,

Algal biology and biofuel production

In the liverwort Riella, at the apical meristem unistratose lateral organs with indeterminate growth (gemmae) and with determinate growth (scales) are formed.Elementary cellular processes underlying morphogenesis of gemmae in Riella helicophylla were studied. Unequal distribution of mitoses results in formation of two lobes and in differentiation of the final intercalary meristem. The shape of the proximal lobe can be attributed to radial gradients of cell cycle duration. In the distal lobe some cells differentiate to rhizoid initials. Scales are distinguished by early cessation of cell division and predominance of expansion growth. Under the influence of the auxin antagonist PCIB rhizoid differentiation is suppressed and gemmae are transformed into scales. After release from the influence of PCIB, new adventitious fan-shaped cell plates distinguished by high divisional activity arise from the apical meristem. PCIB probably abolishes the sink nature of gemmae by interfering with polar auxin transport.