Lignin is an important carbon sink for the environment as it stores about 30 percent of the total carbon on the planet. It allows plants to hydrate and reach tremendous heights up to 100 metres; without lignin, plants could not grow nor survive climate changes. At the cell level, specific lignin chemistries adjust the mechanical strength and waterproofing to support plant growth and survival.

Three-dimension model of plant LACCASE responsible of “encoding” one aspect of lignin chemistry. Carbon skeleton is shown in grey, key amino-acids for lignin oxidation in blue with copper atoms in orange, the volume of the active site is shown in yellow. Model performed with alphafold2 and published in Blaschek and Pesquet, (2021 - 10.3389/fpls.2021.754601). Picture made by Leonard Blaschek

 

Scientists at Stockholm University recently demonstrated that lignin has a chemical “code” that is adapted at the cell level to fulfill different roles in plants (Read more here). How each cell “encodes” specific lignin chemistry however remained unknown. Researchers at the Department of Ecology, Environment and Plant Sciences, DEEP) at Stockholm University led by Edouard Pesquet, Associate-Professor in molecular plant physiology and senior author of the study, just showed that different enzymes called LACCASEs are used by each cell to adjust their lignin “chemical code” in order to resist stresses such as drought or wind. The study finally shows how lignin is spatially controlled at the nanometer level in each plant cell. The findings could be used in both agriculture and forestry to select plants with a lignin chemistry that better resist future climate challenges.

Edouard Pesquet, Associate-Professor at Stockholm University DEEP, senior author and coordinator of the published study, pollinating flowers of Arabidopsis plants. Photo: Delphine Ménar

“The control of lignin chemistry at the cell level is ultimately the mechanism enabling plants to grow, hydrate and resist climate change stresses. These results finally demonstrate how lignin chemistry is controlled and open great possibilities to select plants upon their lignin code to improve crops and trees resistance to water availability problems”, says Edouard Pesquet.

Leonard Blaschek, newly graduated PhD student at Stockholm University DEEP and first author of the study, and Emiko Murozuka, post-doctoral researcher at Stockholm University DEEP and second author of the study, discussing the preparation of plant tissue samples for analyses. Photo: Amanda Gonzalez Bengtsson

The study “Different combinations of laccase paralogs non-redundantly control the lignin amount and composition of specific cell types and cell wall layers in Arabidopsis.” by Blaschek et al. is published in the journal The Plant Cell in November 2022.

This article was originally published on the Stockholm University's website.