CHARACTERIZATION OF WALDMEISTER, A NOVEL DEVELOPMENTAL MUTANT IN ARABIDOPSIS-THALIANA

A novel Arabidopsis thaliana (L.) Heynh. developmental mutant, waldmei ster (wam), is described, This mutant was found in the progeny arising from an Ac-Ds tagging experiment, but does not appear to be tagged by an introduced transposon. This recessive nuclear mutation maps betwee n GAPB and ap1 on chromosome 1 and shows extreme morphological and phy siological changes in both floral and vegetative tissues. Changes to t he vegetative phenotype include altered leaf morphology, multiple rose ttes, stem fasciation, retarded senescence and disturbed geotropic gro wth, Changes to the floral phenotype include delayed flowering, increa sed number of inflorescences, determinate inflorescences, altered numb er and morphology of floral organs, chimeric floral organs, and ectopi c ovules. wam was crossed to a number of previously described floral m utants: apetela 2, apetela 3, pistillata, agamous, and leafy. The phen otype of the double mutant was in each case additive, In the case of a gamous, however, the indeterminate repetitive floral structure of agam ous was lacking, emphasizing the determinate inflorescence growth of w am, The extreme phenotype of the wam mutant is suggestive of a disturb ance to a gene of global importance in the regulation of plant growth and development.