dr. M (Marian) Bemer

Evolution of Plant Transcription Factors

The research in my group focuses on the role of transcription factors in the evolution of plant development. We are comparing gene regulatory networks between species, but also try to understand how small amino acid changes in a transcription factor can bring about changes in its function. We are currently focusing on the evolution of MADS-domain transcription factors such as FRUITFULL (FUL) and SOC1 in different species, including tomato, Arabidopsis, petunia, sugar beet and the orchid Erycina pusilla.

Figure 1

In the model species Arabidopsis, there is only one multifunctional FRUITFULL gene, which functions in fruit development, flowering, leaf development, plant architecture and plant longevity. This gene is active in many different tissues, and the encoded transcription factor forms distinct complexes and regulates different target genes in these tissues. In other plant species, such as tomato, petunia and E. pusilla, several copies of the FRUITFULL gene are present. In most cases, these copies have sub-functionalized, which means that the original functions have become divided over the different copies.

We investigate:

• How the FRUITFULL-like genes evolved, and what the link is between particular sequence motifs and the biological function of the genes.
• What determines the specificity of protein-protein interactions of MADS-domain TFs and the target genes that are regulated in the different tissues (see Figure 1).
• To what extent the role of MADS-domain TFs in the flowering gene regulatory network is conserved between Arabidopsis (monopodial inflorescence) and tomato (sympodial inflorescence).
• Which shifts in the fruit gene regulatory network can explain the evolution from dry to fleshy fruits.

The following people are working in the group:

- Iris Zahn (PhD student), 'Activity of flowering regulators in tomato'

- Kai Thoris, (Phd student), 'A FRUITFULL approach to modify plant traits'

- Chris Roelofsen (technician)

- Kailash Pandey (PhD student), 'Genetic drivers of woodiness in flowering plants'

- Indira Sanchez Bretones (PhD student), 'The mechanisms behind inflorescence termination in tomato'

Former members:

- Xiaobing Jiang (PhD student, 2018-2022), 'FRUITFULL-like transcription factors in tomato'.

- Annemarie Castricum, (PhD student, 2018-2022)