title: Seed production temperature regulation of primary dormancy occurs through control of seed coat phenylpropanoid metabolism.
abstract: Environmental changes during seed production are important drivers of lot-to-lot variation in seed behaviour and enable wild species to time their life history with seasonal cues. Temperature during seed set is the dominant environmental signal determining the depth of primary dormancy, although the mechanisms though which temperature changes impart changes in dormancy state are still only partly understood. We used molecular, genetic and biochemical techniques to examine the mechanism through which temperature variation affects Arabidopsis thaliana seed dormancy. Here we show that, in Arabidopsis, low temperatures during seed maturation result in an increase in phenylpropanoid gene expression in seeds and that this correlates with higher concentrations of seed coat procyanidins. Lower maturation temperatures cause differences in coat permeability to tetrazolium, and mutants with increased seed coat permeability and/or low procyanidin concentrations are less able to enter strongly dormant states after exposure to low temperatures during seed maturation. Our data show that maternal temperature signalling regulates seed coat properties, and this is an important pathway through which the environmental signals control primary dormancy depth.
authors.affiliation: Biosciences, College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK; Department of Crop Genetics, John Innes Centre, Norwich Research Park, Colney Ln, Norwich, Norfolk, NR4, 7UH, UK.
authors.forename: Dana R
authors.initials: DR
authors.lastname: MacGregor
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Kendall
authors.forename: Hannah
authors.initials: H
authors.lastname: Florance
authors.forename: Fabio
authors.initials: F
authors.lastname: Fedi
authors.forename: Karen
authors.initials: K
authors.lastname: Moore
authors.forename: Konrad
authors.initials: K
authors.lastname: Paszkiewicz
authors.forename: Nicholas
authors.initials: N
authors.lastname: Smirnoff
authors.forename: Steven
authors.initials: S
authors.lastname: Penfield
mesh_terms: D017360:Arabidopsis / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins; D005419:Flavonoids / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018525:Germination; D057445:Plant Dormancy; D012639:Seeds / Q000254:growth & development* / Q000378:metabolism; D013696:Temperature
chemical_list: D029681:Arabidopsis Proteins; D005419:Flavonoids
keywords: environmental response; flavonoids; germination; permeability; procyanidins; seed coat; seed dormancy; temperature