Arabidopsis halleri: a perennial model system for studying population differentiation and local adaptation

Abstract

Local adaptation is assumed to occur when populations differ in a phenotypic trait or a set of traits, and such variation has a genetic basis. Here, we introduce Arabidopsis halleri and its life history as a perennial model system to study population differentiation and local adaptation. Studies on altitudinal adaptation have been conducted in two regions: Mt. Ibuki in Japan and the European Alps. Several studies have demonstrated altitudinal adaptation in ultraviolet-B (UV-B) tolerance, leaf water repellency against spring frost and anti-herbivore defences. Studies on population differentiation in A. halleri have also focused on metal hyperaccumulation and tolerance to heavy metal contamination. In these study systems, genome scans to identify candidate genes under selection have been applied. Lastly, we briefly discuss how RNA-Seq can broaden phenotypic space and serve as a link to underlying mechanisms. In conclusion, A. halleri provides us with opportunities to study population differentiation and local adaptation, and relate these to the genetic systems underlying target functional traits.

Abstract

One of the most fascinating observations on plants in natural habitats is the spatial co-variation between functional traits and natural environments. Here, we introduce a small perennial clonal herb, Arabidopsis halleri and its life history as a model system to study local adaptation along environmental gradients. Many studies using this species have addressed altitudinal adaptation in diverse functional traits and population differentiation in response to heavy metal contamination in soils. The species provides us with opportunities to study population differentiation and local adaptation, and relate these to the genetic systems underlying target functional traits using recent molecular tools.