Abstract
Plant cells are surrounded with rigid cell walls and cannot move during development. Cell shape plays an important role for organ shaping and depends on the directions of cell elongation. However, the genetic regulation of anisotropic cell expansion is not well known.
We isolated an Arabidopsis mutant, itosugi (itg), showing defects in elongation of hypocotyls and roots. Cytological analyses of itg mutants revealed that longitudinal cell elongation was suppressed and radial cell expansion was promoted in hypocotyls and roots, suggesting that ITG is required for cell anisotropy.
The ITG gene encodes a plant-specific protein containing armadillo repeats and a C2 domain, which are involved in the protein-protein interaction and lipid binding, respectively. ITG:GFP fusion protein was observed in cytoplasm and around cell periphery. To clarify molecular function of ITG protein, we are analyzing phenotypes of 35S:ITG:GFP transgenic plants.
