Research

A few years ago, we discovered a very interesting organism that morphologically resembled moss. More detailed analyses revealed that this organism is, in fact, multicellular green alga. We named this alga Draparnaldia and we are currently developing it as a new model for studying the evolution of multicellularity and terrestrialization of algae and plants. 
Two major groups of green algae – chlorophytes and streptophytes evolved multicellularity independently and whereas they often co-exist in the same habitats; only Streptophyte algae have managed the transition from water and diversified into the amazing variety of all the land plants.

There are no model systems and genomes of morphologically complex Chlorophyte algae available, which is a limitation to the studies on the evolution of multicellularity in green algae and plants. 

Our Draparnaldia closes a long-standing gap in models availability:
Draparnaldia is a very special in a sense that it is the only Chlorophyte alga, which acquired a complexity comparable to the early land plants and almost managed the transition to land. It has entirely unique morphological adaptations to both, aquatic and terrestrial habitat. Crucially, these adaptations can be induced under controlled laboratory conditions. Thus, Draparnaldia allows studying morphological complexity and terrestrialization in green plants from a completely different point of view.

Our Draparnaldia genome, transcriptome and hormone metabolome gives a strong evidence that this alga will provide crucial insights into evolution of multicellularity and terrestrialization in green plants. 
Draparnaldia genome shows the expanded gene families associated with multicellularity and abiotic stresses when compared to the unicellular alga Chlorophyte alga Chlamydomonas. This first record on expanded gene families associated with multicellularity in algae makes Draparnaldia a strong candidate to study multicellularity. 

Draparnaldia has all known classical plant hormones. Strikingly, our transcriptomic data shows that many of these hormone responses are differentially regulated in aquatic versus terrestrial environment. Moreover, the genome shows that most canonical signaling components for these hormones are missing implying that this lineage evolved alternative mechanism of hormonal signal transduction. Since plant hormones and their signaling are key innovations in plant terrestrialization, our findings support the importance of Draparnaldia as an exceptionally valuable model to study terrestrialization. 

Currently, our laboratory is:

• establishing protocols for CRISPR/Cas and Homologous recombination in Draparnaldia. 
• initiating a project to study the origin of multicellularity in algae
•  initiating a project to study adaptations of Draparnaldia on aquatic versus terrestrial environment
• finalizing the project on the original function of auxin in algae