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Floral MADS box genes and homeotic gender dimorphism in Thalictrum dioicum (Ranunculaceae) – a new model for the study of dioecy
Author(s) -
Di Stilio Verónica S.,
Kramer Elena M.,
Baum David A.
Publication year - 2005
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2005.02336.x
Subject(s) - biology , homeotic gene , mads box , agamous , dioecy , sexual dimorphism , plant reproductive morphology , gynoecium , haplodiploidy , ranunculaceae , botany , evolutionary biology , stamen , zoology , gene , genetics , phenotype , ploidy , arabidopsis , pollen , mutant
Summary In most dioecious angiosperm species, flowers are initially perfect but abort either stamens or carpels during their development, indicating that sex determination occurs after floral organ identity has been established. Dioecious members of the genus Thalictrum (meadow‐rue), however, produce flowers that lack aborted organs. Examination of early flower development of T. dioicum confirms that flowers are male or female from inception, raising the possibility that genetic mechanisms working at or above the level of organ identity promote sex determination through a homeotic‐like mechanism. In order to investigate this possibility, we identified homologs of the organ identity genes PISTILLATA ( PI ), APETALA3 ( AP3 ) and AGAMOUS (AG) from T. dioicum and the hermaphroditic species T. thalictroides . A combination of early and late duplication events was uncovered in these gene lineages and expression analyses indicate that these events are generally associated with divergence in gene regulation. In light of these findings, we discuss the potential of T. dioicum as a new model for the study of sex determination in the basal eudicots.