Project Info

Loasaceae desert dwellers sharing iridoid secondary compounds. Left: Huidobria fruticosa from the Atacama Desert | Photo: T. Böhnert Right: Kissenia capensis from the Namib Desert | Photo: D. Quandt

Desert environments, such as the Atacama or the Namib, with their extreme environmental conditions set high demands on its inhabiting species. Plants have adapted to their various stress factors, however, little is known about the genetic basis of such adaptations that is of importance in the evolution of desert plants. Especially the lack of comparative studies still precludes generalizations. Similarly, knowledge about iridoids, secondary compounds that are thought to play a role in herbivore deterrence and according to our preliminary results may act as sun protection in desert plants is still limited. Using comparative transcriptomics, and integrating biological, chemical, and geological data, we want to address our central question: “is there a common gene set which is relevant for adaptation to aridity in desert dwellers?”

We will compare the transcriptomes of six Loasaceae desert dwellers from the Atacama (Huidobria fruticosa, Presliophytum species) and Namib (Kissenia capensis) with those of their mesic relatives. We will test for signatures of natural selection in water stress responsive genes in the desert species. Gene expression studies with Huidobria fruticosa under controlled conditions in culture and at two climatically different sites in the Atacama Desert will provide insights into the ‘stress anticipation’ ability of desert plants – an important factor in the adaptation to extreme habitats.

Biochemical studies will complement our transcriptomic analyses. We will use Huidobria fruticosa, Kissenia capensis, and their mesic counterpart Xylopodia klaprothioides to identify iridoid compounds with state-of-the-art secondary compound analyses. We will use the generated transcriptomes to investigate the iridoid biosynthesis pathway, the underlying genes and gene regulatory mechanisms in the targeted Loasaceae species.