Designer leaves

Plant leaves arise in a co-ordinated pattern from a specific organ, called the apical meristem, but the mechanism that controls the leaf shape are largely unknown. In February Development, Joanna Wyrzykowska and colleagues from Institute of Plant Biology, University of Zurich, Switzerland show that the shape of a leaf can be controlled by modulation of cell division.

Wyrzykowska et al. worked on R7 Nicotiana tabacum seedlings and used a microinduction technique to manipulate the local expression of genes encoding putative effectors of the cell cycle — a tobacco A-type cyclin and a yeast cdc25. They found that altered cell division in the apical meristem had no influence on organogenesis, but local induction of cell proliferation on the flanks of young leaf primordia led to a dramatic change in lamina development and, thus, leaf shape (Development 2002, 129:957-964).

"These data indicate that the role of cell...