Molecular biologist Marja Timmermans is one of the most highly respected plant geneticists in the world. She has found out how plant cells can communicate with each other using mobile ribonucleic acid molecules. The use of small RNAs (sRNA) is a fundamental principle that applies not only to plant cells, but also to animal and human cells. These days, Timmermans' laboratory methods are used around the world. She has recently been awarded Germany’s most highly endowed international research award - the Alexander von Humboldt Professorship. The award has brought Timmermans from the Cold Spring Harbor Laboratory in the USA to the Centre for Plant Molecular Biology in Tübingen where she will continue her research on sRNA mobility.
Prof. Dr. Marja Timmermans is a biologist who studied first in the Netherlands and then in the USA. "Scientific work means that you are always trying to solve a mystery. Although this is sometimes quite difficult, you feel fantastic when you eventually manage to solve a problem," says Timmermans, explaining why she chose to do a science degree. In 1998, Timmermans went to the USA to carry out research at the renowned Cold Spring Harbor Laboratory on the American East Coast, and, in 2001, she was offered a position as assistant professor. She has been a full professor since 2009. She is also on the editorial boards of several scientific journals and on the selection board of the National Science Foundation amongst others. In April 2015, she began her Alexander von Humboldt Professorship at the Centre for Plant Molecular Biology (ZMBP) at the University of Tübingen.
Timmermans' move to Germany was made possible by the Alexander von Humboldt Foundation, which since 2009 has awarded an annual Alexander von Humboldt Professorship, Germany's most highly endowed international research award. The award provides five million euros in funding over five years for academics in experimental disciplines. Timmermans' position is also funded by the Baden-Württemberg Ministry of Science, Research and the Arts.
Marja Timmermans' interest in molecular biology came about by accident: "I started with microbiology where I worked a lot with cell cultures. But I soon realised that I preferred working with whole organisms – a whole plant or animal," says Timmermans. Her doctoral thesis revolved around maize, which is a popular model organism for basic and applied research in plant biology.
Zimmermans is still working with whole plants, mainly maize or Arabidopsis thaliana, which is another popular model organism for plant research. She is particularly interested in developmental genetics, and her research centres specifically on the formation of plant leaves.
The biologists in Timmermans' laboratory are working with mutants of the two model plants, and are looking for specific phenotypes to find out why plants are able to grow continuously. "The interesting thing about plants is that they begin as a small seed and then grow continuously for a relatively long period," says Timmermans highlighting her fascination for plant research.
"Animals cannot constantly grow; animal foetuses already have recognisable body structures in the early phase of development. This is why we are particularly interested in finding out what makes a plant stem cell a stem cell." The researchers select the most interesting mutants and investigate them in detail on the molecular level to find answers to the following questions: where are the genes that harbour a specific mutation located, how are they expressed, where do the produced proteins go and how do they interact with each other?
Thanks to such studies, the researchers already know that stem cells exchange signals with each other. They produce molecules with which they communicate with each other, for example in a newly formed leaf. "It's a bit like a GPS system that is constantly in communication with headquarters," explains Timmermans. "That's exactly how plant cells communicate with one another, and how they let other cells know which functions each of them will fulfill in the developing leaf."
Timmermans and her team have already found out how plant cells communicate with each other. For Timmermans, this result is the most important discovery in her academic career so far. What the researchers have discovered is small ribonucleic acids (small RNAs/sRNAs) that can move from one cell to another. These particular sRNAs, which can be seen as the plants' language, are 21 nucleotides long and bind to homologous sequences.
Future applications are quite promising
The movement of sRNAs from cell to cell is not just a means of communication in plants. It appears to be a universal principle that also occurs in animal cells. The potential future application of sRNAs seems to be vast. They can be used in medical research for the diagnosis of metastasing tumour cells. They can also be used in the field of agriculture. Agricultural scientists use sRNas, for example, to control plant viruses that have injected their RNA into plant cells and infected them. Controlling plant viruses with sRNAs would be a gentle alternative to the use of toxic pesticides.
"Application of sRNAs in humans and animals is far more complicated," says Timmermans. "However, a lot of work is currently being done to control gene function using sRNAs. In any case, sRNAs are an excellent basic research tool and I am confident that some time in the future they will be used to manipulate agricultural plants and to treat diseases – at least to a certain extent. However, their application in day-to-day medical routines is still a long way off," says Timmermans.
Exploring cell communication
Timmermans has the following goals: first, she wants to study precisely how sRNA moves about, which route it takes when it moves from one cell to another, and in particular, which quantitative responses it triggers. All these are important principles that are far from being clarified in their entirety. "The best thing about being Humboldt Professor is to be able to work on a specific problem for five years and to look at it from completely different angles," said Timmermans. "The research money gives me a tremendous opportunity, namely exploring and solving a basic biological problem."
Timmermans, who very much enjoyed working at the Cold Spring Harbor Laboratory, also appreciates the scientific environment in Tübingen. Above all, she loves the cooperation between the ZMBP and the scientists from the Max Planck Institute for Developmental Biology. "Our research overlaps in many areas, and I am sure that this is very positive for both parties."
The first experiments at the ZMBP are scheduled for June as Timmermans' research group will then be complete: the six scientists who will be joining her come from around the world. Timmermans, who only found out about a year ago that she was to be awarded the Alexander von Humboldt Professorship, is delighted at the progress made so far. "The people in Tübingen and at the ZMBP are very helpful; we would never have come so far in such a short time without them."