XVI International Botanical Congess

Four coch alleles accentuate front-back stipule size asymmetry and affects floral meristem development. Small stipules all face in one direction, inconsistent with spiral leaf initiation. Stipule asymmetry is accentuated near the first floral node. coch complements unifoliata (uni, a LFY homolog) affecting the compound leaf, not stipules. Leaf symmetry is unaltered in uni plants, but both uni and coch alter flowering. COCH affects a graft transmissible factor. coch flowers have: 1) altered organ numbers, 2) flower development in axillary of first sepal, and 3) homeotic petal development. GAs enhance floral abnormalities. Bracts and sepals are stipule-like, leading us to investigate developmental and evolutionary homologies among leaves and flowers. COCH may be a key floral transition gene as the double mutant coch pim (an AP1 homolog) fails to flower. (NSF grant 9405799)