Rob Roelfsema

Abstract

I grew up in the countryside of the Netherlands where I attended a very small primary school with only two classrooms. At this school, I had the same teacher for 3 years, who was fascinated by nature, and I think he sparked my interest in biology. Later in high school, we had some practical courses in biology, and I found it easy to understand the experimental approaches that were used and to interpret the outcomes of these experiments. This made me decide to study biology, for which I went to Groningen, the nearest city to my home village. In those days, most biology students were keen to specialize in human physiology or microbiology. I wondered why so few of them were interested in plants, since one would expect similar physiological systems to work in plants, as in humans and bacteria. Because of this consideration, I decided to write my master's thesis in molecular plant biology and I have remained in that area of science until now.

As a master's student, I really loved being active in research, so I applied for a PhD position in the same laboratory where I conducted the work for my master's thesis. At that time, I did not think much about pursuing a career in plant research, I just enjoyed doing research. The goal of my PhD project was to understand how the drought hormone ABA closes the stomatal pores in the leaf surface of plants. For this purpose, I conducted electrophysiological experiments with guard cells. Although I had some success with my experiments, I could make only a small contribution to the knowledge of ABA responses of stomata.

This situation changed when I became a post-doctoral researcher in the laboratory of Rainer Hedrich in Würzburg, Germany. Here, I started to apply electrophysiology to guard cells in intact plants and found that the cells were much more responsive in their natural environment than in isolation. Using this approach, I could measure the responses of guard cells to light, CO₂ and ABA, which was a great reward. I kept working on stomata, and related topics, trying to understand how plant cells observe and adapt to signals in their environment, such as light and the presence of microorganisms.

I think I have one of the most wonderful jobs. The university gives me, and my students, a lot of freedom to conduct research projects and communicate our results. Moreover, as an Associate Editor of New Phytologist, I automatically get to stay in touch with the research results of others, which gives me new insights that lead to new questions that we try to answer with experiments in our laboratories.

I had some excellent supervisors, starting with my primary school teacher (Harm Soegies) that I mentioned above. During my PhD research period, I was supervised by Hidde Prins, who unfortunately died much too early. Hidde was a very calm and modest person, who did not interfere too much, but instead supported his students to find their own way in plant biology. The character of my later boss, Rainer Hedrich, is very different in this respect, as he has very clear ideas of where plant biology should go. Looking back, I think it is very good to experience such a variety of characters during your career; some supervisors persuade you to take your time and study certain topics in depth, while others open your eyes to find new opportunities for future research projects.

I think that the strength of New Phytologist is that it publishes papers of high quality, which cover a broad area of plant biology. For my research, the development of genetically encoded Ca²⁺ sensors has been very important, since this enabled us to measure cytosolic Ca²⁺ signals in plant cells, without having to inject a calcium-sensitive dye through a microelectrode. The use of R-GECO1, and later R-GECO1-mTurquoise, was pioneered by Rainer Waadt and he published a very nice paper, in which he compared these sensors with other genetically encoded Ca²⁺ sensors in 2017 (Waadt et al., 2017). This red-fluorescent sensor can be used in combination with light-gated channels that are activated with blue or green light (Jones et al., 2022) and therefore will be very useful in future optogenetic studies.

More recently, I enjoyed reading the paper of Sanmartín et al. (2024), in which long-distance signals were studied in the liverwort Marchantia polymorpha. M. polymorpha has only one Glutamate Receptor-like (GLR-like) gene, and Sanmartin et al. could show that the encoded GLR-like protein is essential for the propagation of long-distance signals. Moreover, they found that in contrast to Arabidopsis, long-distance signals are not associated with jasmonate-dependent wounding responses in M. polymorpha. This study nicely shows how model systems in nonseed plants can help to disentangle complex signal transduction systems found in seed plants.

I deeply respect the common spider plant (Chlorophytum comosum) (Fig. 1) that is able to survive on the window ledge of my office. I really mistreat these plants, since they have to survive my holiday without water, but they manage to get through these periods and start growing again and set flower, as soon as I come back. It shows the remarkable strength of plants to grow in almost any place on Earth. I think that this capacity of plants is obvious if you observe abandoned houses, in which trees can get to decent sizes in only 20 years, after people have left the place. It shows us that we may have a big impact on the globe right now, but in the long run plants are much more important. If we do not take care of our planet, I am sure that plants will take over again, and this can already been seen in areas that have become unsuitable for humans, like the surroundings of Chernobyl.