Evolution of the miR5200-FLOWERING LOCUS T flowering time regulon in the temperate grass subfamily Pooideae.

Flowering time is a carefully regulated trait controlled primarily through the action of the central genetic regulator, FLOWERING LOCUS T (FT). Recently it was demonstrated that a microRNA, miR5200, targets the end of the second exon of FT under short-day photoperiods in the grass subfamily Pooideae, thus preventing FT transcripts from reaching threshold levels under non-inductive conditions. Pooideae are an interesting group in that they rapidly diversified from the tropics into the northern temperate region during a major global cooling event spanning the Eocene-Oligocene transition.

Evidence for an Early Origin of Vernalization Responsiveness in Temperate Pooideae Grasses.

The ability of plants to match their reproductive output with favorable environmental conditions has major consequences both for lifetime fitness and geographic patterns of diversity. In temperate ecosystems, some plant species have evolved the ability to use winter nonfreezing cold (vernalization) as a cue to ready them for spring flowering. However, it is unknown how important the evolution of vernalization responsiveness has been for the colonization and subsequent diversification of taxa within the northern and southern temperate zones.

Comparative Transcriptomics Indicates a Role for SHORT VEGETATIVE PHASE (SVP) Genes in Mimulus guttatus Vernalization Response.

The timing of reproduction in response to variable environmental conditions is critical to plant fitness, and is a major driver of taxon differentiation. In the yellow monkey flower, Mimulus guttatus, geographically distinct North American populations vary in their photoperiod and chilling (vernalization) requirements for flowering, suggesting strong local adaptation to their surroundings. Previous analyses revealed quantitative trait loci (QTL) underlying short-day mediated vernalization responsiveness using two annual M.

Evolution of VRN2/Ghd7-Like Genes in Vernalization-Mediated Repression of Grass Flowering.

Flowering of many plant species is coordinated with seasonal environmental cues such as temperature and photoperiod. Vernalization provides competence to flower after prolonged cold exposure, and a vernalization requirement prevents flowering from occurring prior to winter. In winter wheat (Triticum aestivum) and barley (Hordeum vulgare), three genes VRN1, VRN2, and FT form a regulatory loop that regulates the initiation of flowering.

Phylogenetic analyses place the Australian monotypic Revwattsia in Dryopteris (Dryopteridaceae).

Revwattsia fragilis (Watts) D.L. Jones (Dryopteridaceae), originally described as a Polystichum Roth by the pioneer Australian botanist Reverend W.