Common liverwort (Marchantia polymorpha) needs water to reproduce, so lies low to the ground and lives in damp places. Like mosses and ferns, it does not make flowers or seeds, and disperses via spores.
Transcription factors: genetic switches
During development, gene activity is turned on and off by proteins called transcription factors. Each transcription factor can as a switch for multiple genes, making them master regulators for developmental processes.
Transcription factors are grouped into families based on their molecular structure. A family can contain many different but related transcription factors, some of which act together with others. One example is a three-protein structure called an MBW complex, made up of one member from each of the MYB, bHLH and WDR families.
Marchantia develops heart-shaped thalli as it grows. Thea photographs these thalli to track development.
How did these switches evolve?
MBW complexes regulate many processes in plants, including the formation of pigments and protective hairs called trichomes. It is not known when in evolutionary history the complexes first formed, or how they diversified in function over time. Identifying how these transcription factors work in various distantly related plants will help us understand more about this.
Thea Kongsted (Department of Plant Sciences)
Thea is fascinated by how all of the organisms alive today (including ourselves!) evolved from a common ancestor. How did they come to look so different and form new interactions with their environments? To understand this, she studies the genetic regulation of developmental processes in liverworts and compares this with their distant relatives, the flowering plants. They last shared a common ancestor around 470 million years ago, when plants first moved onto land.