Abstract
Arabidopsis thaliana crumpled leaf(crl) mutants have yellowish green and crumpled leaves, and contain fewer and giant chloroplasts (Asano et al., 2004).In this study, we analysed the structure of CRL gene homologs in the moss Physcomitrella patens and characterized their function. A. thaliana has a single AtCRL gene whereas P. patens has three CRL genes(PpCRL1,PpCRL2,PpCRL3). We generated gene disruptants by homologous recombination. Single gene disruptants exhibited similar phenptypes of the wild-type mosses. In contrast, the PpCRL1/2 double disruptants showed severe retardation of growth, aberrant morphogenesis and abnormal plastid division in the protonemata. However, PpCRL1/3 double disruptants resulted in a similar phenotype of the wild type. This observation suggests that PpCRL1 and 2 gene plays a critical role in protonemal growth of P. patens. To prove this we have generated PpCRL2/3 double and PpCRL1/2/3 triple disruptants.
