Characterization of<i>waldmeister</i>, a novel developmental mutant in<i>Arabidopsis thaliana</i>

Abstract

A novel Arabidopsis thaliana (L.) Heynh. developmental mutant, waldmeister (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 between GAPB and ap1 on chromosome 1 and shows extreme morphological and physiological changes in both floral and vegetative tissues. Changes to the vegetative phenotype include altered leaf morphology, multiple rosettes, stem fasciation, retarded senescence and disturbed geotropic growth. Changes to the floral phenotype include delayed flowering, increased number of inflorescences, determinate inflorescences, altered number and morphology of floral organs, chimeric floral organs, and ectopic ovules . wam was crossed to a number of previously described floral mutants: apetela 2, apetela 3, pistillata, agamous, and leafy. The phenotype of the double mutant was in each case additive. In the case of agamous, however, the indeterminate repetitive floral structure of agamous was lacking, emphasizing the determinate inflorescence growth of wam. The extreme phenotype of the wam mutant is suggestive of a disturbance to a gene of global importance in the regulation of plant growth and development.