SLU news

Plant cell wall research opens up new opportunities for bioengineering

Published: 19 June 2024
Félix Barbut wearing a white trousers and a dark jacket is standing in front of a lake in a typical Northern Swedish landscape

Secondary cell walls provide the plant with stability and protection against damage and pathogens. PhD student Félix Barbut from Ewa Mellerowicz’s group at UPSC and SLU has been studying the role of xylan, a long-chain carbohydrate, that is part of the secondary cell wall. He not only identified new molecular players involved in maintaining the integrity of the cell wall, but also interesting target points for bioengineering. Read more about Félix Barbut’s research in this interview with him.

You studied secondary cell walls in Arabidopsis and aspen. What motivated you to choose this PhD project in Ewa Mellerowicz’s research group?

Félix Barbut: I was particularly drawn to pursue my PhD at UPSC due to my profound interest in the complexities of plant science and my specific fascination with how trees adapt to their environment. Reading the PhD proposal, I immediately recognized how well it aligned with my prior research on hormonal interplay, abiotic stress, and the regulation of reactive oxygen species. Moreover, I was thrilled by the broad approach of the project and its ambitious goals.

What is the role of secondary cell walls and why is it important to better understand their structure and function?

Félix Barbut: Secondary cell walls are crucial structures in various aspects of plant development, particularly in trees. They help plants resist numerous challenges such as pathogen attack or strong winds and enable trees to live for thousands of years and grow up to one hundred meters tall. Understanding the structure and dynamics of secondary cell walls could help us develop more resilient crops to withstand climate change and promote more sustainable agricultural practices. Additionally, wood, which is composed of secondary cell walls, is a major sink of atmospheric carbon dioxide. Biofuels derived from wood could serve as an alternative to fossil fuels, potentially achieving net-zero carbon emissions.

What do you consider as the major outcome of your thesis?

Félix Barbut: In my thesis, we identified several molecular players potentially involved in maintaining the integrity of secondary cell walls, a system that allows plants to sense external stresses and adjust wood development accordingly. We also created hybrid aspen trees and Arabidopsis plants that are more drought-resistant and easier to convert to biofuel. However, these plants exhibited slower growth, indicating a need to further optimize secondary cell wall integrity for creating more promising crops and trees. Additionally, we discovered that lipids, fatty compounds that are for example part of cell membranes, may play a more significant role in wood than previously understood.

Did your results match your expectations or working hypotheses?

Félix Barbut: Given the exploratory nature of our research, we did not set much specific expectations for the outcomes. However, we observed many consistent responses to drought and cell wall defects in herbaceous plants and perennial trees. Notably, unexpected findings - such as the presence of lipids in the wood and the drought resistance of cell wall-impaired lines - have paved the way for further research on the secondary cell wall integrity maintenance.

Did you had to overcome any challenges during your PhD?

Félix Barbut: Yes, I faced several challenges during my PhD. First, I had to adapt to a new country, which was a significant transition. Additionally, the onset of the COVID-19 pandemic in the middle of my studies presented considerable difficulties. Overall, the PhD journey is filled with ups and downs, and I am grateful for the resilience I developed during these tough times, from which I learned a great deal.

What are you planning to do now? Do you like to continue in Academia?

Félix Barbut: I am committed to pursuing a career in academia and hope to secure a permanent position in the future. Currently, I have one more paper to publish at UPSC. After that, I plan to seek a position abroad, which I believe will give me more chances of building a successful career.


About the public defence:

Félix Barbut, Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, defended his PhD thesis on Friday, 14th of June 2024. Faculty opponent was Professor Thorsten Hamann, Professor at the Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway. The thesis was supervised by Ewa Mellerowicz.

Title of the thesis:

Unraveling the Role of Xylan in the Integrity of Secondary Cell Walls: Insights from Arabidopsis and Aspen

Link to Félix Barbut’s PhD thesis