Biochemist and Green TE research leader Dolf Weijers: ‘I find it exciting to come up with new research questions from different angles.’ Photo: Ducan De Fey
‘A plant cell is an inflated car tyre. How can it possibly sense that you’re pressing a finger against it?’ That is a question biochemist Dolf Weijers wants to answer in the multidisciplinary Gravitation project Green TE.
‘It can certainly be useful, but I myself am not in the scientific tradition of digging ever deeper, deeper and deeper and confining yourself to a single model organism. I am better at setting something up than at keeping it going for a long time. Innovating by bringing together things that don’t naturally go together. Because it is precisely at the interfaces between disciplines that there is much to be gained: by looking at things differently and choosing different angles. When you put on a different pair of glasses, you see new things’, says biochemist Dolf Weijers (born 1976) of Wageningen University & Research. Together with mechanobiologist Joris Sprakel, he leads the consortium Green TE (Green Tissue Engineering), which received an NWO Gravitation grant of €22.9 million in 2024 to conduct ten years of research into the sense of touch in plants. ‘Very little is known about how plants feel and respond to touch. Biologists have focused on genes and chemical compounds, but have little understanding of the influence of all the forces acting on and between plant cells’, says Weijers, one of the keynote speakers at NWO Life on 27 and 28 May in Egmond aan Zee.
He illustrates the success that choosing new angles can bring with research from his laboratory on the plant hormone auxin. ‘It has been studied for a century. It is a very simple molecule, but it does an enormous number of things in plants: root and flower formation, fruit set, cell elongation – you name it. These responses are often much faster at the cellular level than you would expect on the basis of gene transcription and protein transport. That is why last year we used phosphoproteomics and discovered that auxin very rapidly phosphorylates a whole series of proteins. Within ten minutes, a cell modifies as much as 5 per cent of all its proteins. And this turns out to be an evolutionarily ancient system, operating in land plants, liverworts and algae alike’, says Weijers. A completely new insight with major implications for plant growth and development, published in Cell (4 January 2024).
‘How can an inflated tyre possibly sense that you’re pressing a finger against it?’
It also illustrates Weijers’ fascination with fundamental, curiosity-driven research – even though he never studied at a university, but instead completed a higher vocational training course for laboratory technicians in Enschede from 1993. ‘It was only when I sat in lecture halls that I discovered there was such a thing as a scientist: someone who is paid to be curious and to do research. That set me on the path of research at an early age: I started my PhD in Leiden at 20 and, at 26, was already given the opportunity to become a group leader during a postdoc in Tübingen’, says Weijers. ‘The role of group leader suits me best: I find it exciting to come up with new research questions and to approach them from a different angle. Research where everything has already been worked out appeals to me less. I don’t think colleagues raised their eyebrows because I didn’t follow the conventional academic path. Everyone looks primarily at what you put on the table in terms of original ideas, positive energy and drive. It did give me extra motivation to prove myself.’ That appears to have worked out, with his appointment as professor (in 2012), two ERC grants (in 2011 and 2019), and Vidi (2006) and Vici fellowships (in 2015).
Mini-organs
The impetus for Green TE, in which seven Dutch university groups from various disciplines participate, came when Weijers attended a talk by Joris Sprakel a number of years ago, who was then working in Wageningen as a physical chemist on synthetic polymers. ‘He showed fluorescent molecules that change colour when they sense pressure. That struck me as a very valuable tool if it could work as a force sensor in living plant cells’, says Weijers. ‘From biomedical research we already know that growing mini-organs only succeeds when the cells are in the right matrix and that forces play a formative role. In plant tissue culture too, we have strong indications that this plays a crucial role.’
Experiments with the developed plant-based fluorescent force sensor show that forces also generate biochemical signals in living plant cells, opening up research into the sense of touch. Sprakel and Weijers drafted the first research proposal for this within an hour. ‘Initially we are focusing on the model plant Arabidopsis, but for the second phase we have model systems available at phylogenetic nodes, such as common liverwort, a fern and an alga, as well as crops like lettuce. ‘Compared to an animal cell, a plant cell is an inflated car tyre. How can such a tyre detect that you are pressing a finger on it?’, Weijers wonders aloud. ‘This project could well be of use for propagation and tissue culture: thirty companies have already come forward who are welcome to have a front-row view on a regular basis. But utility or a specific application is certainly not our point on the horizon – greater understanding is. We want to try to understand plants better.’