抄録
Endoreduplication is a common process in plants but its contribution to developmental regulation of organ shape is still poorly understood. We studied the Arabidopsis frill1 mutant that has serrated petals and sepals without gross changes in plant morphology. A small reduction in cell number with a concomitant increase of cell size and nuclear size were observed in the distal part of frl1 petals. The frill1 mutant had a mutation in STEROL METHYLTRANSFERASE 2 and an altered sterol composition. We found an unusual increase in the ploidy level in the distal part of petals but not in leaves, cotyledons or roots, suggesting that the ploidy level was increased but only in tissues that do not normally endoreduplicate. Our results demonstrate a new link between sterols and endoreduplication, and also show that the suppression of endoreduplication is important for petal morphogenesis.
