Intraspecfic variation in cold-temperature metabolic phenotypes of Arabidopsis lyrata ssp. petraea

Matthew P. Davey, F. Ian Woodward, W. Paul Quick

Animal and Plant Sciences, Western Bank, University of Sheffield, Sheffield, UK


Atmospheric temperature is likely to be a key factor in determining the distribution of a plant species. Alongside this, plant populations growing at the margin of their range may exhibit traits that indicate genetic differentiation and adaptation to their local abiotic environment.  We investigated whether geographically separated marginal populations of Arabidopsis lyrata ssp. petraea have distinct metabolic phenotypes that are associated with exposure to cold temperatures. Seeds of A. petraea were obtained from populations along a latitudinal gradient, namely Wales, Sweden and Iceland and grown in a controlled cabinet environment.  Detailed targeted metabolic fingerprints and profiles were obtained. Principal component analysis (PCA) of metabolite fingerprints revealed metabolic phenotypes for each population and temperature.  It is suggested that amino acids and carbohydrates were responsible for discriminating populations within the PCA. Mannose, glucose, fructose, sucrose and raffinose concentrations were different between cold treatments and populations, especially in the Welsh population, but polyhydric alcohol concentrations were not.  The free amino acid compositions were population specific, with fold differences in most amino acids, especially in the Icelandic populations, with gross changes in amino acids associated with the citric acid cycle, in particular glutamine metabolism.  Metabolite fingerprinting and profiling has proved to be sufficiently sensitive to identify metabolic differences between plant populations at different atmospheric temperatures. These findings show that there is significant natural variation in cold metabolism among populations of A. l. petraea.