Abstract
massugu2 (msg2/iaa19) mutant grows similarly to wild type with an exception of slightly reduced fecundity. But, hand self-polination recovers infertility of msg2 flowers. In this study we observed development of flower organs to find physiological basis of reduced fecundity in msg2. In wild type flowers, anthers deposited pollen grains on stigma papilla when the length of stamens exceeded the length of a pistil. On the other hand, most stamens did not exceed pistils and failed in pollinating in msg2 flowers. Stamens elongated because of elongation of stamen filaments. Number of epidermal cells in a cell file of stamen filaments remained constant irrespective of length of filaments. It was also not changed by msg2 mutation. Analysis with MSG2promorter-GUS showed that MSG2 was expressed in stamen filaments after they started to elongate faster than ever. These results suggest that MSG2 plays an important role in cell elongation of stamen filaments.
