Interview with Associate Editor Charlotte Kirchhelle

Charlotte Kirchhelle

What inspired you to become a scientist?

Growing up, I didn't want to be anything – I wanted to be everything! When I finished high school, I still didn't know what I wanted to be. My older sister studied medicine, and I always thought what she was doing was exciting – up until the point where she started learning about disease. I liked the basic physiology and bodily functions with a bit of physics sprinkled in, and I figured that biology is just the first half of medicine, where you study how things in nature work. That's how I decided what field to go into in about 2 hours. It turned out to be a fantastic decision!

What ultimately drew you towards plant biology?

It happened a bit by chance. My undergraduate degree covered a broad range of topics, including plant genetics. The chair of the plant genetics department at the time would invite students who did well for a tour of the lab at the end of our first year. This was the first time I had properly visited any research lab, and I thought it was fantastic. Afterwards, I started a practical in the lab, and I thought, ‘this is this what I want to do!’. My first research project was on Arabidopsis thaliana, the model system I still use today. I stuck with plant biology because what's most fascinating to me is the way that plants live their life. Plants are stationary, but simultaneously highly dynamic and flexible, and their sessile lifestyle and modular body plan creates a completely different life strategy compared to that of animals. They can adjust to different environments throughout their lifespan, for example by growing new organs, and they can look very different depending on the circumstances. Yet this flexibility is generated by robust genetic programmes that produce similar shapes over and over again. This contrast between plants being developmentally dynamic and flexible but at the same time having a very low degree of variability on certain biological levels is something that really intrigues me.

Can you tell us a bit more about your career path so far?

I did both my undergraduate and my master's degree at the Technical University of Munich. My master's project was focused on genetics, but I realised what I was missing was the ‘black box’ of what actually happens inside the cell, so I wanted to learn more cell biology and understand how plants shape their organs. During my master's, I did an internship at the John Innes Centre in the UK. I was very keen to do my PhD in the UK as well, so I moved to the University of Oxford in 2012 to join the lab of Ian Moore, who was a fantastic cell and membrane biologist with a deep knowledge of endomembrane trafficking. In Ian's lab, my project focused on a very specific transport pathway that helps cells grow in the right direction by delivering material to a sub-cellular domain called the geometric edge, where two faces of the cell surface meet. When we first described this pathway in 2016, many open questions remained, but Ian passed away just a year after I finished my PhD. As a postdoc, I ended up taking over many of the activities of his team, and I decided to take this research theme forward, because contextualising the developmental aspects that emerge from cell biology was always something that I was passionate about, and Ian was very gracious about giving me the space to explore that. It's nice to be able to continue the work that we initiated together. While at Oxford, I received a Leverhulme Research Fellowship, which allowed me to start my first small team. In 2021, I moved to France, and now I work at the National Institute for Agriculture, Food and Environment Research (INRAE). I'm based in Lyon at the Laboratory for Plant Reproduction and Development. The position I have, Chargée de Recherche, is a bit like an Associate Professorship, but without any teaching requirements. Pure research positions like mine are a real luxury because you can have a very long-term vision of your research from a relatively early point in your career.

Your career has taken you from Germany to the UK, and now to France. What lessons have you taken from these international experiences?

Every academic system has strengths and weaknesses, and I prefer to focus on the strengths. In the German system, I had a lot of freedom to decide what I wanted to focus on for my undergraduate and master's degrees. I spent time in the lab acquiring hands-on research experience and a good technical grounding. I came out of those degrees already an experimentalist, whereas it's very difficult to get that degree of experimental experience at that level in the UK.

In the UK, the John Innes Centre was buzzing with excitement about research, and I was amazed by the amount of interaction between people from different teams. It was a very open atmosphere with lots of scientific exchange and a fairly flat hierarchy, which were some of the main reasons why I went back to the UK for my PhD. It was an amazing time for me to expand my ideas with collaborators in engineering and physics and with people from incredibly different backgrounds. There was also a strong focus on writing beautiful papers and grants and formulating ideas. Everything I know about how to communicate and share data with the scientific community comes from my experience in the UK. One of my struggles is actually extracting something meaningful from the huge amount of literature, so I think it's very important as an author to translate your data in a way that makes it accessible for other people. This is a real strength of the UK research system – reading and writing, absorbing and packaging information, are strongly emphasised during the educational process.

While I was looking for a permanent position, the papers that I got most excited about came from France. Now that I'm here, I can see why. The structure of the French academic system is really special: there is much more space for long-term projects because there are permanent positions at various levels of the system. Highly qualified researchers can sometimes get positions as permanent ‘research engineers’ after their PhD. People are also very interested in investing in collaboration and willing to contribute upfront without expecting things to pay off immediately. This creates a greater capacity to do riskier, paradigm-shifting projects that may take 10 years to complete, which is very hard to do on a short-term contract. In a system where the majority of the team will be turned over every 3 years, you need to design projects that can be done in 3 years. We have those projects here for the PhD students, but we also have projects that can continue over a longer period, carried out by people with extremely high technical expertise, and that is very fun.

When you started your own lab, what challenges did you encounter as a new PI?

I've been incredibly lucky, because I started my first team in the UK at an institution where I had already been for years. Everyone was supportive and I had virtually everything that I could ask for, but it was a slightly complicated situation because my mentor had passed away. I took on a lot of his responsibilities to tide things over, and I also had just had a baby, so it was a very intense time. Later, when I moved to France, I spoke no French whatsoever! The administration here is very complicated, so that was not an ideal circumstance. At my very first faculty meeting, I ended up asking a lot of questions. Afterwards, I felt embarrassed about talking so much and wondered whether I should have kept quiet. But the head of the department thanked me for participating actively in the meeting, because often, the problem is that people don't speak up. That moment was really nice because it made me feel relevant, even as the youngest and least experienced person in the room. I have not stopped asking questions and participating in meetings since! I encourage people to engage and be an active part of the culture and environment of your institution. As a PI, you get to shape that a bit, but only if you are participating and not being quiet. Reflecting back on that time, I now realise that a lot of the stress that comes with being a new PI is created inside, from questioning your own performance. I think some of the stress of these initial challenges can be absorbed by finding a peer group of other young PIs, because we all often worry about the same universal themes.

What is the main theme of your lab's research and what questions are you are trying to answer just now?

The biggest question that we're interested in is how a plant makes an organ. This has been a perennial question for hundreds of years, but compared to 100 or even 20 years ago, we now have a multi-scale view of morphogenesis, and we need to bridge these scales to understand how different types of information come together across the molecular, cell and tissue scale. Today, we can build multi-disciplinary research programmes to combine computational modelling and quantitative analysis with real-time imaging, cell biology, biochemistry and mechanics. I think these tools can now give an answer to this very old question by providing a different and more complete view of how shapes are generated.

We are particularly interested in the molecular players at the cell edge. During my PhD, we knew of very few proteins that were localised at the cell edge. We only knew that, in mature tissues, the cell wall adjacent to the cell edge often had unique biochemical features and composition, and some edge-localised cytoskeleton regulators had been described. Since 2016, we and other groups have identified several proteins that localise to the cell edge. This year, we showed that receptors that interact with the cell wall are patterned to this region, suggesting that cells perceive their environment at this conspicuous cell edge signalling domain. Additionally, other groups have shown that some enigmatic factors, called SOSEKI proteins, localise to cell edges. Their function is still not entirely clear, but they label different edges within the cell, almost like a coordinate system. We're also working on understanding edge-based growth control and where the cell edge gets its polarised identity from. An exciting hypothesis is that the mechanism of polarisation is actually not plant specific – in principle, it's something that could emerge in different multicellular systems, because the ingredients can be found in many organisms. I think we've only gotten a small glimpse of the huge biochemical diversity in terms of proteins related to signalling, cell wall modifications, memory and organisation that seem to be enriched in this domain.

What are some big questions in plant cell biology that you find particularly interesting?

I think endomembrane trafficking is fascinating because similar regulators exist in yeast, animals and plants, but they have often evolved completely differently, and how these factors have been explored in each system is radically different. I think we can learn a lot from comparing these components to see which basic functions are conserved. Another topic I find incredibly interesting is how cellular function is adapted in different conditions. Plants are so adaptive, not just in their development but also in their physiology. They can't regulate their temperature, yet they experience huge changes in environmental conditions, and different parts of the plant experience very different environments. Their cell biology has adapted to this variability, but how cell processes actually change in response to differences in external factors is still poorly understood, because we focus so much energy on doing cell biology in very controlled environments.

What made you interested in taking on the role of Associate Editor with JCS, and what impact would you like to make?

I was excited to receive the invitation because I really value JCS. I often browse JCS for the beautiful cell biology, but I think there's not as much plant cell biology as there should be! I think that sometimes plant biologists make the mistake of only publishing in plant-specific journals rather than general biology journals, which is a shame because the target audiences are different. I would like to make a contribution to integrating more plant science in a general journal. Also, like many people, I'm a bit worried about the current publication model. I think there are huge problems in the for-profit sector, and Open Access publishing isn't currently handled in a helpful way. I personally think that, ironically, publications in high impact factor, for-profit journals are not necessarily a good marker for whether someone is competitive on the job market. However, they can determine whether your research arrives in the community or is just not seen. I'm very happy to support a community journal, which I think can be one of the solutions to the problems we see in the system and create visibility for important, thought-provoking papers.

What sort of papers would you like to see more of at JCS?

I want to see more plant papers! I'm a bit biased, but this is my mission. I hope that not only will more of these papers be submitted, but that they will really reach a different community. I often go to plant meetings, but when I go to more general cell biology meetings, I realise how much plant scientists can live in our own community bubble. It's a lovely community, but sometimes we need to branch out a bit. However, branching out can be a hurdle at times, and that's maybe why people go to the journals they are comfortable with. For example, our most recent paper was editorially rejected from a journal with a broader audience without being reviewed. I talked about this work repeatedly with the community, it's been very well received, and ultimately publishing it in a plant journal was fairly straightforward, so the impact for a broad audience clearly needs to come across better at the editorial stage. My impression is that plant cell biology tends to end up more in plant journals than, for example, plant development biology, although I think in principle there's no reason for it. Let's see whether we can change that!

How do you approach finding important, relevant papers from outside the plant biology community?

When I want to start learning about a completely new discipline, I find a recent review and read the papers that review cites. Still, it's sometimes hard to identify the big papers in the field. The essential step is going into the cited literature and doing a forward projection. From the papers that I like best, I check which new papers are citing those. This gives you a sense of where the field is at the moment. My team also have a journal club format where everyone is assigned a few journals to screen by going through an entire issue's publications. In total, we follow about 30–40 journals spread across specialised and generalist journals. Then we come together and flag papers we think might be interesting, which helps highlight some papers outside our normal framework that we wouldn't have otherwise picked up. The trick to splitting the workload is to assign people that are passionate about a specific subject to read journals in that area, so it becomes less of a chore. For me, this strategy has opened the door to topics that I hadn't thought about before.

What advice, on elements inside or outside the lab, would you give to young scientists developing their careers?

Oftentimes, it's easy for you to be your own block. You might not even consider applying for certain jobs or grants because you think you're not there yet. I've had really fantastic mentors who always encouraged me to just go for it, and I did. Sometimes it worked out, and it was fantastic. When it didn't work out, writing an application was still a useful process, because it helped me crystallise ideas. I think that as soon you have a productive proposal, you should go for it. Think about what you would like to do and how you can integrate that. Technically, I've studied the same thing my whole career, so maybe I'm not a good example, but even though I've worked on the same question, I've changed my approaches. For example, I started as an experimental biologist, but I spent 5 years learning about computational modelling from engineers, because even though I had very little ability in that area in the beginning, I felt that it was the approach we needed. If you feel stuck within the sphere of what you know now, it confines what you can develop into. Don't let what you can do at the moment define what you will do next.

I also want to say that it is absolutely possible to start a family even at an early stage in your academic career. I've had many conversations with people who question whether it can be done and feel like it's a huge hurdle. The reality is, I don't think it is that difficult! I had one child during my postdoc and one just as I started my team in Oxford on a fixed-term contract. I'm very happy that I didn't postpone it because, first of all, I wanted to have kids. If that is important to you, delaying that decision because you feel you won't be competitive can be heartbreaking if you're ultimately not successful in academia. And if you are successful, it's only going to get worse! Once you lead a team, people are dependent on you. It's much easier to have a kid when you're a postdoc or PhD student and you're only responsible for yourself.

Are you involved in any science outreach projects?

I did a lot of outreach in the UK, and I really loved it. I gave talks at schools and museums and organised an exhibition called ‘Inside a Plant Cell’ with the Linnaean Society and the Botanic Garden at Oxford, with samples of plants labelled with fluorescent proteins that people could look at in real time under a microscope. As a fundamental biologist, I'm passionate about asking fundamental questions about plants. But as a plant scientist, I'm typically asked three things: Do you know what this plant is? Why is my rose sick? Will you make better crops to feed the world? Other plant scientists are trying to answer all of these questions, but I just want to know how things work! In other disciplines, like astrophysics or particle physics, the general public celebrates asking fundamental questions about the world as exciting collective endeavours of humankind. For plant cell biology, or maybe cell biology in general, not so much. Children will readily accept that cells are just awesome, but the older people get, the more they feel that biologists should be doing something ‘useful’. What I've always wanted to do with outreach is create the same kind of excitement that people have about space exploration for understanding the complexity of a cell. I'm not doing much outreach at the moment because it's very difficult to do when your language skills aren't up to scratch, but once my French is better, I will definitely start again!

Finally, could you tell us an interesting fact about yourself that people wouldn't know by looking at your CV?

I like making things; it doesn't really matter what. I like woodwork, sewing, knitting, painting and cooking. Right now, it's knitting season, so I'm making hats. I just like making things with my hands. I think that's probably why I became an experimental biologist, because there is a very tactile component to it, and that brings me joy.

Charlotte Kirchhelle was interviewed by Amelia Glazier, Features & Reviews Editor for Journal of Cell Science. This piece has been edited and condensed with approval from the interviewee.