Abstract
Morphogenesis of leaf blade is dependent on the determinate and two-dimensional cell proliferation. We found that this process is subdivided into two phases based on the properties of direction of cell proliferation in Arabidopsis thaliana. During Phase I, cell proliferation in a leaf primordium occurs along its longitudinal axis, and during Phase II this restriction is released so that cell proliferation occurs two-dimensionally. angustifolia3 (an3) mutant of A. thaliana is defective in the maintenance of cell division activity during Phase II and develops narrower leaves than wild type. Cloning of AN3 gene revealed that it encodes a putative transcription coactivator. We searched for AN3-interacting proteins and identified putative transcription factors by yeast two-hybrid system. To test if genes for these transcription factors are coordinately expressed with AN3, examination of their tissue-specific expression patterns is in progress. Phenotypes of overexpression of AN3 and AN3 interacting proteins will also be reported.
