Abstract
Three class 1 KNOX genes (PpKN1/MKN2, MKN4, and MKN5) have been cloned in the moss Physcomitrella patens. We inserted the GUS reporter gene at the end of coding sequence of each gene. The transgenic mosses showed GUS activity specifically in egg cells and young sporophytes. Triple disruptants of the three genes produced normal gametophores. Arabidopsis thaliana expressing PpKN1 cDNA under the control of cauliflower mosaic virus 35S promoter showed lobed leaves, which is similar to those in A. thaliana expressing other class 1 KNOX genes. These data suggest that the three class 1 KNOX genes are not involved in gametophytic shoot formation and that they function in meristem formation and maintenance of the sporophyte, which do not form shoot but exists transiently to form seta and sporangium. Phenotypic analyses of sporophyte development in single, double, and triple disruptants are ongoing and will be presented.
