Sjoerd Woudenberg: Understanding vascular development using Ceratopteris as the model species

One of the most important innovations during land plant evolution is the development of vasculature tissue, which links the root to the shoot and vice versa. The development of vasculature allowed land plants to colonize the wide range of habitats we see today and is crucial for their development and growth. This important innovation arose during land plant evolution in the fern lineage, crucially positioned as sister group of all seed plants. Flowering plants are extensively studied and recently bryophytes gained a lot of momentum too. In contrast, fern research is still at a very early stage with much to learn, but with great potential as ferns are the best of both worlds. Ferns tend to be simpler than flowering plants like Arabidopsis while containing the developmental complexity like organs which are lacking in bryophytes. Recently, crucial tools like a genome and transformation protocols were developed to work with a model fern species in the lab: The C-fern Ceratopteris richardii. This fern will allow us to better understand the evolutionary origin of the vasculature but also of other plant organs like roots and shoots in general.

Besides looking at the evolutionary origin, focussing on embryonic development will allow us to understand the developmental origin of vasculature. For example, which molecular factors are crucial in specifying embryonic cells to become vasculature-initials? This is even not well understood in the extensively studied Arabidopsis. What are the molecular basics necessary for vasculature development and its conservation throughout evolution? Besides, working with such an unexplored model allows for the discovery of novel regulators of vasculature development. In this project we use an extensive transcriptional analysis coupled to detailed morphological evidence by microscopy to pinpoint the molecular factors crucial in fern development. Further in vivo validation in Ceratopteris and Arabidopsis will help us understand their functioning and conservation. This will aid understanding vasculature development but also plant evolution in general by filling in the fern-gap.