Abstract
Determination of leaf size is one of key processes in leaf morphogenesis but it has been poorly understood. We have isolated a number of mutants of Arabidopsis thaliana with altered leaf size. Here we characterized some of these mutants, #488, #675 and #9c. These mutants are semi-dominant and exhibit similar phenotypes. We named #488 as grandifolia1 (gra1) and characterized it in detail. gra1 leaves has about two-fold greater cells than wild-type leaves do while its cell size is reduced to 70% of wild-type size. Final cell number in a leaf is determined largely by the rate and the duration of cell proliferation. Thus we determined the kinetics of cell proliferation in leaf primordia of gra1. This analysis revealed that cell proliferation continued a longer period than wild type, suggesting an important role of GRA1 in the determination of the duration of cell proliferation in leaf primordia.
