Spontaneous homeotic transformations have been described in natural populations of both plants and animals, but little is known about the molecular-genetic mechanisms underlying these processes in plants. In the ABC model of floral organ identity in Arabidopsis thaliana, the B- and C-functions are necessary for stamen morphogenesis, and C alone is required for carpel identity. We provide ABC mo...

IN examining various groups of plants, in the hope of finding one which would throw fresh light on the question of sex determination, the dioecious forms of Lychnis suggested themselves as being particularly suitable. The genus Lychnis, as a whole, is hermaphrodite, and even the dioecious species may readily exhibit this character. In the female flower rudiments of stamens are always present an...

APETALA3 is a MADS box gene required for normal development of the petals and stamens in the Arabidopsis flower. Studies in yeast, mammals and plants demonstrate that MADS domain transcription factors bind with high affinity to a consensus sequence called the CArG box. The APETALA3 promoter contains three close matches to the consensus CArG box sequence. To gain insights into the APETALA3 regul...

Regulatory mechanisms controlling basic aspects of floral morphogenesis seem to be highly conserved among plant species. The class B organ identity genes, which are required to establish the identity of organs in the second (petals) and third (stamens) floral whorls, are a good example of such conservation. This work compares the function of two similar class B genes in the same genetic backgro...

Abstract During buzz pollination, bees use vibrations to remove pollen from flowers. Vibrations at the natural frequency of pollen-carrying stamens are amplified through resonance, resulting in higher amplitude vibrations. Because release depends on vibration amplitude, could increase removal by vibrating stamens. However, few studies have characterized frequencies and compared them buzz-pollin...

U1 small nuclear ribonucleoprotein (snRNP)-70K (U1-70K), a U1 snRNP-specific protein, is involved in the early stages of spliceosome formation. In non-plant systems, it is involved in constitutive and alternative splicing. It has been shown that U1snRNP is dispensable for in vitro splicing of some animal pre-mRNAs, and inactivation of U1-70K in yeast (Saccharomyces cerevisiae) is not lethal. As...

Hermaphroditic flowers have evolved primarily under the selection on male function. Evolutionary modification often leads to stamen differentiation within flowers, or "heteranthery", a phenomenon intrigued scientists since the 18(th) century until recently. However, the genetic basis and molecular regulation mechanism has barely been touched. Here we conducted comparative transcriptome profilin...

Comparative developmental morphology was used to assess structural homology of flowers in Dalea, Marina, and Psorothamnus of the tribe Amorpheae (Fabaceae: Papilionoideae). Dalea, Marina, and some species of Psorothamnus have an unusual petal-stamen synorganization (stemonozone) in which free petals are inserted on a region that is continuous with fused stamen filaments. Developmental studies o...

In flower development, specification of stamens and carpels requires the AGAMOUS gene. A recent study has now shown that AGAMOUS also plays more specific roles in the regional activation of sporocyte formation.

Cyclamen persicum (cyclamen) is a commercially valuable, winter-blooming perennial plant. We cloned two cyclamen orthologues of AGAMOUS (AG), CpAG1 and CpAG2, which are mainly expressed in the stamen and carpel, respectively. Cyclamen flowers have 5 petals, but expression of a chimeric repressor of CpAG1 (CpAG1-SRDX) caused stamens to convert into petals, resulting in a flower with 10 petals. B...