Abstract
Cell elongation is one of important factors for plant morphogenesis. In Arabidopsis, inflorescence stems elongate rapidly and straightly. To elucidate molecular mechanism of this process, we have isolated fiz1 (frizzy shoot1) mutant that shows frizzy or curling inflorescence stems and pedicels in Arabidopsis. The elongation of etiolated hypocotyl and root growth is also inhibited in this mutant. Moreover the root hair also developed abnormally. fis1 mutant is semi dominant. We also isolated fiz2 mutant similar to fiz1 in hypocotyl and root phenotypes. We found the missense mutation of ACT8 and ACT2 in fiz1 and fiz2, respectively. It is shown that actin family is strongly involved in cell elongation of shoot and root.
