Micromechanical behavior of the apple fruit cuticle investigated by Brillouin light scattering microscopy

authored by

Timm Landes, Bishnu Prasad Khanal, Hans Lukas Bethge, Tina Lehrich, Maximilian Seydi Kilic, Franz Renz, Miroslav Zabic, Moritz Knoche, Dag Heinemann

Abstract

The cuticle is a polymeric membrane covering all plant aerial organs of primary origin. It regulates water loss and defends against environmental stressors and pathogens. Despite its significance, understanding of the micro-mechanical properties of the cuticle (cuticular membrane; CM) remains limited. In this study, non-invasive Brillouin light scattering (BLS) spectroscopy was applied to probe the micro-mechanics of native CM, dewaxed CM (DCM), and isolated cutin matrix (CU) of mature apple fruit. The BLS signal arises from the photon interaction with thermally induced pressure waves and allows for imaging with mechanical contrast. The derived loss tangent showed significant differences with wax extraction from the CM and further with carbohydrate extraction from the DCM, consistent with tensile test results. Spatial heterogeneity between anticlinal and periclinal regions was observed by BLS microscopy of CM and DCM, but not in CU. The key conclusions are: (1) BLS is sensitive to micro-mechanical variations, particularly the strain-stiffening effect of the cutin framework, offering insights into the CM’s micro-mechanical behavior and underlying chemical structures; (2) CM and DCM exhibit spatial micro-mechanical heterogeneity between periclinal and anticlinal regions

Organisation(s)

PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines
Hannover Centre for Optical Technologies (HOT)
Institute of Horticultural Production Systems
Institute of Cell Biology and Biophysics
Institute of Inorganic Chemistry

Type

Article

Journal

Communications Biology

Volume

8

Publication date

04.02.2025

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Medicine (miscellaneous), General Biochemistry,Genetics and Molecular Biology, General Agricultural and Biological Sciences

Electronic version(s)

https://doi.org/10.1038/s42003-025-07555-5 (Access: Open)