Alexis Peaucelle: investigating the dynamics of the plant cell wall

How did you come to join INRAE? 
I first joined INRAE as a Master's student and stayed on to complete my PhD within the same laboratory. My postdoctoral research at the Physics Laboratory of Paris 7 was carried out in collaboration with the Primary Cell Wall team at IJPB, which meant I spent a great deal of time on site. I was then recruited as a research scientist through a disability recruitment scheme within the same team, where I have remained ever since. For several years after my appointment, I continued to spend most of my time working at the Physics Laboratory of Paris 7 through a secondment arrangement. I subsequently took a two-year sabbatical at the Sainsbury Laboratory, University of Cambridge, in ’Eliot Meyerowitz's group, before returning to France and joining the IJPB laboratory on a permanent basis. 

What is your research about? 
My aim is to understand how plants manage to be so remarkably beautiful. In other words, I study how they grow and acquire their shape — a process known as morphogenesis. My research focuses on growth processes, and in particular on the role of the cell wall, the rigid extracellular matrix that surrounds plant cells and must deform to allow them to expand. We have shown that a chemical modification — the de-methylesterification of one of the cell wall's main components, the polysaccharide homogalacturonan — is both necessary and sufficient for cell growth. We also demonstrated that this chemical change causes the cell wall to expand through a change in shape, rather like a brick swelling.
More recently, it has been shown that this chemical modification releases methane into the atmosphere. Rising atmospheric CO₂ levels lead to increased production of homogalacturonan, whose enhanced de-methylesterification not only accelerates plant growth but also results in greater methane emissions, amplifying the greenhouse effect, with methane having up to 28 times the warming potential of CO₂. Furthermore, climate warming causes many plants to grow more rapidly, a process that also appears to involve increased methane release. Our understanding of this fundamental mechanism of plant growth therefore reveals an additional risk of climate destabilisation. 
In response to the climate emergency, our laboratory is committed to using the knowledge and cutting-edge technologies we have developed to contribute to a greener economy. A sustainable bioeconomy relies largely on the polymers and sugars found in plant cell walls, and we are therefore investigating ways to improve the valorisation of these biopolymers. 

Do you have any additional responsibilities? 
I have relatively few additional responsibilities. I serve on the governing bodies of the Biosphera Graduate School and am also a member of the IJPB departmental council. Alongside my research, I teach food engineering at Sorbonne University as part of the AGRAL engineering programme. I am also actively involved in public engagement and science communication. I particularly enjoy projects that bring together art and science, such as "Virtuose par nature", developed with Nicolas Frize in the Parc du Sausset. 

How is your work organised on a day-to-day basis? 
No two days are ever quite the same. The constants are our coffee breaks and lunch with colleagues from the laboratory. Beyond that, my schedule may include microscopy sessions, long periods of image analysis, and the never-ending task of applying for research funding. The highlights are always the discussions — whether spontaneous or planned — with colleagues and students, as well as public talks and university teaching. 

What are your ambitions for the future? 
My main wish is simply to maintain the momentum we have built. Thanks to substantial French and European funding, we now have access to state-of-the-art technologies that provide entirely new ways of studying plant growth. I hope we can preserve this technological lead by continuing to invest in both advanced instrumentation and technical expertise. I also hope that our approach, which combines fundamental research with the translation of knowledge into industrial applications, will continue to prove successful, and above all that I will be able to maintain both aspects of my work. They are essential if we are to remain at the forefront of scientific and technological innovation. It is important that the current enthusiasm for our research is not lost simply because it may seem too long-term or too far removed from immediate practical applications. We certainly need solutions to the climate crisis now, but scientific research inevitably takes time and requires substantial investment. My hope is that the public's entirely legitimate expectations will not be undermined by the complexity and difficulty of the scientific and technological breakthroughs that are needed to address the profound changes we are facing. 

And outside work? 
For many years, I devoted a great deal of time to music, studying classical guitar at the conservatoire and singing in a choir. I also trained in the visual arts. Since having children, however, I have had to reduce the time I can devote to these activities. They require the ability to step away completely from everyday life for a while each day. Instead, I have taken up sewing. Faced with the monotony of reasonably priced clothing, I decided to make my own. For the past ten years, I have worn either shirts, trousers and coats that I have made myself, or carefully selected high-quality second-hand clothes.

Mini CV
2025 – Senior Scientist, INRAE
2015 – Habilitation to Supervise Research (HDR), Paris-Sud University, now Université Paris-Saclay
2013–2014 – Long-term research placement at the Sainsbury Laboratory, University of Cambridge, Seconded to the Faculty of Physics,University Paris 7 now Université Paris Cité, Laboratory of Matter and Complex Systems
2010–2012 – Seconded to the Faculty of Physics, University Paris 7 now Université Paris Cité, Laboratory of Matter and Complex Systems, Non-Equilibrium Systems Group: genetic and mechanical interactions in morphogenesis using plant, jellyfish and zebrafish models (an evo-devo approach), employing Atomic Force Microscopy (AFM).
2008 – Research Scientist, INRA Versailles, Cell Biology Laboratory, Primary Cell Wall Group, now the phyWALL team: investigation of the role of a chemical modification of the cell wall (demethylesterification of homogalacturonans) in plant mechanics and morphogenesis, and characterisation of its genetic regulation.
2006–2007 – Postdoctoral Research Fellow, Faculty of Physics, University Paris 7 now wUniversité Paris Cité, Laboratory of Matter and Complex Systems: mechanical control of phyllotaxis; investigation of the physical forces involved in plant growth.
2002–2006 – PhD in Plant Physiology, INRA Versailles, Cell Biology Laboratory, one of the founding laboratories of the Institute of Plant Sciences Paris-Saclay (IJPB).
2001–2002 – Master's Degree (DEA) in Plant Cellular and Molecular Physiology, Paris-Sud University, now Université Paris-Saclay


Research developed at the Institute Jean-Pierre Bourgin for Plant Sciences.