Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published March 1992 | Published
Journal Article Open

SUPERMAN, a regulator of floral homeotic genes in Arabidopsis

Abstract

We describe a locus, SUPERMAN, mutations in which result in extra stamens developing at the expense of the central carpels in the Arabidopsis thaliana flower. The development of superman flowers, from initial primordium to mature flower, is described by scanning electron microscopy. The development of doubly and triply mutant strains, constructed with superman alleles and previously identified homeotic mutations that cause alterations in floral organ identity, is also described. Essentially additive phenotypes are observed in superman agamous and superman apetala2 double mutants. The epistatic relationships observed between either apetala3 or pistillata and superman alleles suggest that the SUPERMAN gene product could be a regulator of these floral homeotic genes. To test this, the expression patterns of AGAMOUS and APETALA3 were examined in superman flowers. In wild-type flowers, APETALA3 expression is restricted to the second and third whorls where it is required for the specification of petals and stamens. In contrast, in superman flowers, APETALA3 expression expands to include most of the cells that would normally constitute the fourth whorl. This ectopic APETALA3 expression is proposed to be one of the causes of the development of the extra stamens in superman flowers. The spatial pattern of AGAMOUS expression remains unaltered in superman flowers as compared to wild-type flowers. Taken together these data indicate that one of the functions of the wild-type SUPERMAN gene product is to negatively regulate APETALA3 in the fourth whorl of the flower. In addition, superman mutants exhibit a loss of determinacy of the floral meristem, an effect that appears to be mediated by the APETALA3 and PISTILLATA gene products.

Additional Information

© 1992 by Company of Biologists. (Accepted 27 November 1991) We thank our colleagues Laura Brockman, Caren Chang, Gary Drews, Shing Kwok, and Mark Running for insightful discussion and critical review. We also thank Elizabeth Schultz, George Haughn, Russell Malmberg, John Alvarez, and David Smyth for providing genetic material, and Pat Koen of the Electron Microscope Facility at Caltech for technical advice. This study was assisted by National Science Foundation grant DCB-8703439 to E.M.M. J.L.B. was partially supported by training grant 5T32-GM07616 of the National Institutes of Health, H.S. was supported by a long-term fellowship from the Human Frontier Science Program, T.J. was supported by NIH post-doctoral grant GM-13667-02, D.W. was an EMBO long-term fellow, U.M. was supported by the DFG (Leibnizprogramm to Herbert Jackie, grant Ju 179/2-1 to Gerd Jurgens).

Attached Files

Published - BOWdev92.pdf

Files

BOWdev92.pdf
Files (13.3 MB)
Name Size Download all
md5:ec8c6954be64ff1673ddb7361ec0ac84
13.3 MB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 17, 2023