title: Adaptation to altitude affects the senescence response to chilling in the perennial plant Arabis alpina.
abstract: In annual plants with determinate growth, sugar accumulation signals high carbon availability once growth has ceased, resulting in senescence-dependent nutrient recycling to the seeds. However, this senescence-inducing effect of sugars is abolished at cold temperature, where sugar accumulation is important for protection. Here, natural variation was exploited to analyse the effect of chilling on interactions between leaf senescence, sugars, and phytohormones in Arabis alpina, a perennial plant with indeterminate growth. Eight accessions of A. alpina originating from between 2090 and 3090 m above sea level in the French Alps were used to identify heritable adaptations in senescence, stress response, sugars, and phytohormones to altitude. Accessions from high altitudes showed an enhanced capacity for sucrose accumulation and a diminished loss of chlorophyll in response to chilling. At warm temperature, sucrose content was negatively correlated with chlorophyll content, and sucrose treatment induced leaf senescence. Chilling resulted in lower indole-3-acetic acid, but higher zeatin and jasmonic acid contents. Interactions between sugar and phytohormones included a positive correlation between sucrose and jasmonic acid contents that may be involved in promoting the stress-dependent decline in chlorophyll. These findings reveal regulatory interactions that underlie adaptation in the senescence and stress response to chilling.
authors.affiliation: Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, United Kingdom a.wingler@ucl.ac.uk.
authors.forename: Astrid
authors.initials: A
authors.lastname: Wingler
authors.affiliation: Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 643, E-08028 Barcelona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Juvany
authors.affiliation: Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, United Kingdom.
authors.forename: Caroline
authors.initials: C
authors.lastname: Cuthbert
authors.affiliation: Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 643, E-08028 Barcelona, Spain.
authors.forename: Sergi
authors.initials: S
authors.lastname: Munné-Bosch
mesh_terms: D000064:Acclimatization; D000531:Altitude; D031214:Arabis / Q000254:growth & development / Q000502:physiology*; D050260:Carbohydrate Metabolism; D003080:Cold Temperature; D005602:France; D010937:Plant Growth Regulators / Q000378:metabolism*; D018515:Plant Leaves / Q000254:growth & development / Q000502:physiology
chemical_list: D010937:Plant Growth Regulators
keywords: Arabis alpina; cold stress; jasmonic acid; phytohormones; senescence; sucrose; zeatin.