Abstract
Compensation is a phenomenon observed in several mutants and transgenics associated with a decrease in cell number within the leaves, where the size of leaf cell is larger than that of wild type plants. These observations suggest that the intrinsic mechanisms might exist so that expansion of differentiating cell is negatively regulated by proliferating cells in leaf development. At present, genetic and molecular mechanisms of compensation are quite unclear. To elucidate the mechanism of compensation system, we hypothesized that the compensation system can be divided into two distinct processes. That is, an induction stage: reduction of cell proliferation in leaf primordia and a response stage: activation of cell expansion process. To address this hypothesis, genetical analyses have been done on angstifolia3 mutant which shows typical compensation and several other mutants with reduction of either cell number or cell size. We will discuss on the data obtained from the above analyses.
