XVI International Botanical Congess

Recent years have seen the identification and characterization of a number of genes that have a role in shoot apical meristem maintenance and leaf initiation, but most studies have analyzed simple-leaved model species such as maize and arabidopsis. This talk will focus on our examination of KNOTTED-like homeobox (KNOX) gene expression in the compound-leaved tomato, as well as in Brassicaceae species, such as Neobeckia aquatica and Lepidium spp., that exhibit a range of leaf morphologies, and in Welwitschia mirabalis, in the sister group to the angiosperms. In some cases the expression patterns seen vary from those reported for simple-leaved model organisms. For example, in tomato the Class I KNOX genes are not downregulated at sites of leaf initiation. These results will be discussed in the context of simple vs. compound leaf development and evolution.