Abstract
Control of leaf size is central for its appropriate function. To understand mechanisms controlling leaf size, we focused on 'compensation' in which a mutation such as angustifolia3 (an3) causes a decrease in cell number in leaf primordia, which in turn induces an increase in the final size of leaf cells, thereby compensating the reduction of leaf size. In this study, we generated a series of mutants in which leaf cell number is reduced to various levels using the an3 mutant and two mutants, grandifolia1-D (gra1-D) and jaw-D, that increase the number of leaf cells. Characterization of these plants showed that compensation is induced only when the number of leaf cells is substantially reduced, suggesting a threshold level of leaf cells for the induction of compensation. This threshold is found to be associated with a specific pathway of cell proliferation, since jaw-D but not gra1-D was able to suppress compensation.
