Kartierung der molekularen Grundlagen der Wuchsformabweichungen in tropischen alpinen Arabidopsis thaliana
Zusammenfassung der Projektergebnisse
In alpine environments steep gradients in temperature can occur over short geographical distances. This makes altitudinal clines effective systems for exposing the genetic and physiological basis for adaptations to allow survival in harsh environments. Several specific growth forms are enriched in high altitude environments, including low-stature and prostrate shrubs, cushion plants, tussock grasses and herbaceous rosette plants. Shifts to low-stature and more compact forms are strikingly common across species and have been hypothesized to result from an increased need for resistance to cold temperatures. Arabidopsis thaliana is a powerful ecological model because we can apply diverse genetic and molecular tools and knowledge developed in this system to identify the specific molecular and genetic bases for evolutionary change. We have collected over 1000 A. thaliana accessions from altitudes ranging from 2222 to 4432 m over eight mountain ranges in Ethiopia, including altitudinal transects across four of these. We find striking variation in growth form between high and lower altitude accessions, with accessions from the highest altitudes exhibiting one of two phenotypic extremes: either extreme dwarfism or a prostrate growth habit with plagiotropic growth. These phenotypic shifts are reminiscent of those classically associated with high altitude across diverse species. In this research, we identified genetic variants with large effects on growth form shifts and characterised the polygenic architecture of the height trait.
