Streptophyte evolution: plastidial signals and core abiotic stress physiology of the closest algal relatives to embryophytes
Dissertation
Datum der mündl. Prüfung:2023-03-23
Erschienen:2023-12-04
Betreuer:Prof. Dr. Jan de Vries
Gutachter:Prof. Dr. Jan de Vries
Gutachter:Prof. Dr. Ivo Feussner
Dateien
Name:Janine Fürst-Jansen_PhD thesis.pdf
Size:62.5Mb
Format:PDF
Description:PhD thesis main document
Zusammenfassung
Englisch
Plant terrestrialization facilitated the emergence of the enormous and diverse macroflora. It changed the face of our planet. On this singular evolutionary event, which occurred approximately 550 million years ago, land plants emerged from within the clade of Streptophyta. Many facets of this event remain obscure and are among the central questions of plant evolutionary research. One of the all-time general interest questions is: why did plant terrestrialization happen only once in the evolution of the green lineage? One attempt to answer this question is to take a closer look at the factors that might have enabled this event. The earliest land plants likely had to overcome a barrage of environmental challenges to thrive in the terrestrial habitat. To do so, they had to possess the molecular toolkit for responding to terrestrial stressors effectively. Understanding facets of this molecular core-toolkit was therefore the aim of this thesis. I compared a set of molecular traits shared by land plants and their closest algal relatives, the streptophyte algae, to infer the trait repertoire that the last common ancestor of land plants and streptophyte algae possessed. This inference can give an idea of the molecular trait setup of the earliest land plants. In this thesis, the focus was on stress-responsive traits throughout the paraphylum of streptophyte algae, with a particular focus on the class of Zygnematophyceae—the phylogenetically closest streptophyte algal relatives to land plants. The algal progenitors of land plants were likely pre-adapted to terrestrial environments. Indeed, a mosaic of core-stress response mechanisms that are well studied in land plants can be found in the streptophyte algal lineage as well and some of them were studied in detail in this thesis using a comparative approach.
Keywords: Evolution; Plants; Algae; Stress Response; Comparative genomics; Plant terrestrialization