Abstract
We previously revealed that the YABBY gene DROOPING LEAF (DL) plays an essential role in rice carpel specification. To further understand the genetic mechanism of floral organ specification in rice, we studied the functions of the two paralogous C-class genes, OsMADS3 and OsMADS58, because C-class genes play predominant roles in carpel specification in eudicots.
Major phenotype of loss-of-function mutants of OsMADS3 is homeotic transformation of stamens into lodicules in whorl3, while that of suppression lines of OsMADS58 gene is indeterminate organ development and abnormal carpel morphology in whorl4. These results indicate that functions of the two C-class genes are diversified to work differently in each whorl. In addition, expression analyses suggest that DL and C-class genes function independently. We also found the involvement of the C-class genes in lodicule differentiation in rice flower.
The molecular mechanism of the functional diversification of C-class gene activities will be discussed.
