title: Source of nitrogen associated with recovery of relative growth rate in Arabidopsis thaliana acclimated to sustained cold treatment.
abstract: To determine (1) whether acclimation of carbon metabolism to low temperatures results in recovery of the relative growth rate (RGR) of plants in the cold and (2) the source of N underpinning cold acclimation in Arabidopsis thaliana, we supplied plants with a nutrient solution labelled with (15) N and subjected them to a temperature shift (from 23 to 5 °C). Whole-plant RGR of cold-treated plants was initially less than 30% of that of warm-maintained control plants. After 14 d, new leaves with a cold-acclimated phenotype emerged, with the RGR of cold-treated plants increasing by 50%; there was an associated recovery of root RGR and doubling of the net assimilation rate (NAR). The development of new tissues in the cold was supported initially by re-allocation of internal sources of N. In the longer term, the majority (80%) of N in the new leaves was derived from the external solution. Hence, both the nutrient status of the plant and the current availability of N from external sources are important in determining recovery of growth at low temperature. Collectively, our results reveal that both increased N use efficiency and increases in nitrogen content per se play a role in the recovery of carbon metabolism in the cold.
authors.affiliation: Department of Geography, Environment and Earth Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
authors.forename: Lindsey J
authors.initials: LJ
authors.lastname: Atkinson
authors.forename: David J
authors.initials: DJ
authors.lastname: Sherlock
authors.forename: Owen K
authors.initials: OK
authors.lastname: Atkin
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D017360:Arabidopsis / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology; D003080:Cold Temperature / Q000009:adverse effects; D009584:Nitrogen / Q000378:metabolism*; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism / Q000502:physiology
chemical_list: D009584:Nitrogen
keywords: acclimation; low temperature; nitrogen uptake; specific leaf area