# Neutrons reveal the dynamics of leaf thylakoids in living plants

## TL;DR

This study uses neutrons to explore how leaf membranes in living plants move and change shape.

## Contribution

It is the first use of high-resolution neutron scattering to study photosynthetic membrane dynamics in living plants.

## Key findings

- Thylakoid stacks in duckweed behave as rigid systems with low bending coefficients.
- Single thylakoid leaflets show greater flexibility and bi-continuous surfactant phase dynamics.
- Classical lipid bilayer models are insufficient for describing complex biological membrane systems.

## Abstract

The study is the first known exploration of photosynthetic membranes dynamics in living plants by high resolution quasielastic neutron scattering spectroscopy. We investigated the mobility and flexibility of thylakoid membranes in common duckweed (Landoltia punctata) and identified dynamics across various length scales corresponding to individual membranes and membranes stack. We employed classical models typically used to study lipid bilayers to characterize the undulation modes and rigidity of the membranes and reveal how structural variations influence the observed complex dynamics. Our findings show that the stacks of thylakoids in duckweed behave as rigid systems, exhibiting an effective bending coefficient in the lower range associated with surfactant membranes. In contrast, the single thylakoid leaflets display greater apparent flexibility and are well situated within the bi-continuous surfactant phase dynamics. While our observations enhance the understanding of the intricate architecture and mobility of photosynthetic cellular machinery, they also highlight the limitations of applying ideal lipid membranes models to describe complex biological systems. This work opens more questions and the need for further investigations across extended length and time scales, as well as the importance of rigorous sample preparation and experimental control.

The online version contains supplementary material available at 10.1038/s41598-025-22747-z.