Front. Plant. Sci. http://doi.org/bn8b (2016)

Arabidopsis thaliana has one of the largest geographical ranges of any plant species. It is a native of Eurasia and North Africa and can be found as a naturalized alien on all continents except Antarctica. Its ecotypes therefore provide a superb resource to study how a single species can adapt to various environments. William Adams III and colleagues at the University of Colorado Boulder have now demonstrated that this adaptability is itself adapted to local conditions.

The researchers investigated the physiological performances of three A. thaliana ecotypes originally collected at the same longitude, but separated by over 2,200 km, from Sweden in the north to Italy in the south. These were then grown under different day/night temperature regimes approximating the normal conditions at the points of origin of each ecotype. A battery of physiological characteristics was measured for each plant including photosynthetic capacity, leaf thickness, levels of β-carotene, leaf vein density and many others.

The temperature regime affected all of these characteristics, however, the magnitude of the change varied with ecotype and the conditions of its native range. The researchers identified two classes of characteristics: one that included characteristics like photosynthetic capacity and extent of phloem, whose degree of acclimation related to the ecotypes' native temperature, and a second that included transpiration rate and leaf vein density, whose acclimation varied with the rainfall in the native range.