title: Comparative Transcriptomics Indicates a Role for SHORT VEGETATIVE PHASE (SVP) Genes in Mimulus guttatus Vernalization Response.
abstract: 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. guttatus populations that differed in their vernalization response. To narrow down candidate genes responsible for this variation, and to reveal potential downstream genes, we conducted comparative transcriptomics and quantitative PCR (qPCR) in shoot apices of parental vernalization responsive IM62, and unresponsive LMC24 inbred lines grown under different photoperiods and temperatures. Our study identified several metabolic, hormone signaling, photosynthetic, stress response, and flowering time genes that are differentially expressed between treatments, suggesting a role for their protein products in short-day-mediated vernalization responsiveness. Only a small subset of these genes intersected with candidate genes from the previous QTL study, and, of the main candidates tested with qPCR under nonpermissive conditions, only SHORT VEGETATIVE PHASE (SVP) gene expression met predictions for a population-specific short-day-repressor of flowering that is repressed by cold.
authors.affiliation: Department of Plant Science, University of Vermont, Burlington, Vermont 05405 Jill.Preston@uvm.edu.
authors.forename: Jill C
authors.initials: JC
authors.lastname: Preston
authors.affiliation: Department of Plant Science, University of Vermont, Burlington, Vermont 05405.
authors.forename: Jinshun
authors.initials: J
authors.lastname: Zhong
authors.affiliation: Department of Plant Science, University of Vermont, Burlington, Vermont 05405.
authors.forename: Meghan
authors.initials: M
authors.lastname: McKeown
authors.affiliation: Department of Biology, Syracuse University, New York 13244.
authors.forename: Meghan
authors.initials: M
authors.lastname: den Bakker
authors.affiliation: Department of Biology, Syracuse University, New York 13244.
authors.forename: Jannice
authors.initials: J
authors.lastname: Friedman
mesh_terms: D003080:Cold Temperature; D019295:Computational Biology / Q000379:methods; D035264:Flowers / Q000235:genetics; D020869:Gene Expression Profiling / Q000379:methods; D018506:Gene Expression Regulation, Plant; D059647:Gene-Environment Interaction; D017343:Genes, Plant; D032241:Mimulus / Q000145:classification / Q000235:genetics*; D058977:Molecular Sequence Annotation; D010641:Phenotype; D017440:Photoperiod; D010802:Phylogeny; D018515:Plant Leaves; D040641:Quantitative Trait Loci; D059467:Transcriptome
keywords: Mimulus guttatus; SHORT VEGETATIVE PHASE; flowering time; local adaptation; photoperiod; vernalization