title: Metabolic dynamics during autumn cold acclimation within and among populations of Sitka spruce (Picea sitchensis).
abstract: • Autumnal cold acclimation in conifers is a complex process, the timing and extent of which vary widely along latitudinal gradients for many tree species and reflect local adaptation to climate. Although previous studies have detailed some aspects of the metabolic remodelling that accompanies cold acclimation in conifers, little is known about global metabolic dynamics, or how these changes vary among phenotypically divergent populations. • Using untargeted GC-MS metabolite profiling, we monitored metabolic dynamics during autumnal cold acclimation in three populations of Sitka spruce from the southern, central, and northern portions of the species range, which differ in both the timing and extent of cold acclimation. • Latitudinal variation was evident in the nature, intensity, and timing of metabolic events. Early development of strong freezing tolerance in the northern population was associated with a transient accumulation of amino acids. By late autumn, metabolic profiles were highly similar between the northern and central populations, whereas profiles for the southern population were relatively distinct. • Our results provide insight into the metabolic architecture of latitudinal adaptive variation in autumn acclimation and show that different mechanisms are the basis of early October cold hardiness and autumn-acclimated cold hardiness.
authors.affiliation: Department of Wood Science, Faculty of Forestry, The University of British Columbia, 2424 Main Mall, V6T 1Z4, Vancouver, BC, Canada.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Dauwe
authors.affiliation: Department of Forest Sciences, Faculty of Forestry, The University of British Columbia, 2424 Main Mall, V6T 1Z4, Vancouver, BC, Canada.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Holliday
authors.affiliation: Department of Forest Sciences, Faculty of Forestry, The University of British Columbia, 2424 Main Mall, V6T 1Z4, Vancouver, BC, Canada.
authors.forename: Sally N
authors.initials: SN
authors.lastname: Aitken
authors.affiliation: Department of Wood Science, Faculty of Forestry, The University of British Columbia, 2424 Main Mall, V6T 1Z4, Vancouver, BC, Canada.
authors.forename: Shawn D
authors.initials: SD
authors.lastname: Mansfield
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D016000:Cluster Analysis; D003080:Cold Temperature; D016002:Discriminant Analysis; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D016018:Least-Squares Analysis; D053858:Metabolic Networks and Pathways; D055442:Metabolome; D008954:Models, Biological; D010641:Phenotype; D028222:Picea / Q000235:genetics / Q000378:metabolism*; D011157:Population Dynamics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012621:Seasons; D013997:Time Factors
chemical_list: D012333:RNA, Messenger