The maize rough sheath2 gene and leaf development programs in monocot and dicot plants

Leaves of higher plants develop in a sequential manner from the shoot apica l meristem. previously it was determined that perturbed Leaf development in maize rough sheath2 (rs2) mutant plants results from ectopic expression of knotted1-like (knox) homeobox genes. Here, the rs2 gene sequence was found to be similar to the Antirrhinum PHANTASTICA (PHAN) gene sequence, which e ncodes a Myb-Like transcription factor. RS2 and PHAN are both required to p revent the accumulation of knox gene products in maize and Antirrhinum leav es, respectively. However, rs2 and phan mutant phenotypes differ, highlight ing fundamental differences in monocot and dicot leaf development programs.