Host: The Japanese Society of Plant Physiologists
Pages 0240
To elucidate the mechanisms underlying dioecious flower development, we have identified a SUPERMAN (SUP) homolog, denoted SlSUP, in the dioecious plant Silene latifolia. The introduction of a genomic copy of SlSUP into the Arabidopsis thaliana sup (sup-2) mutant restores an excess-stamen phenotype. SlSUP is a single-copy autosomal gene that is expressed exclusively during the development of the female flower of Silene latifolia. The expression of SlSUP is first detectable in whorls 2 and 3 to persist in the stamen primordia until the ovule has completely matured. When female plants of S. latifolia are infected with the smut fungus Microbotryum violaceum, stamens develop in the female flower. Hence, an infected-female flower seems morphologically to be hermaphroditic. The expression of SlSUP was maintained at stage 5 but markedly reduced until stage 8 in developing stamens of the infected-hermaphrodite-like flower. These expression patterns suggest that SlSUP functions in the suppression of stamen development.
