Correlated mechanochemical maps of Arabidopsis thaliana primary cell walls using atomic force microscope infrared spectroscopy

Abstract

Spatial heterogeneity in composition and organisation of the primary cell wall affects the mechanics of cellular morphogenesis. However, directly correlating cell wall composition, organisation and mechanics has been challenging. To overcome this barrier, we applied atomic force microscopy coupled with infrared (AFM-IR) spectroscopy to generate spatially correlated maps of chemical and mechanical properties for paraformaldehyde-fixed, intact Arabidopsis thaliana epidermal cell walls. AFM-IR spectra were deconvoluted by non-negative matrix factorisation (NMF) into a linear combination of IR spectral factors representing sets of chemical groups comprising different cell wall components. This approach enables quantification of chemical composition from IR spectral signatures and visualisation of chemical heterogeneity at nanometer resolution. Cross-correlation analysis of the spatial distribution of NMFs and mechanical properties suggests that the carbohydrate composition of cell wall junctions correlates with increased local stiffness. Together, our work establishes new methodology to use AFM-IR for the mechanochemical analysis of intact plant primary cell walls.

The impact of PAC‐loaded polymer membrane thickness on chloroform removal and comparison of solvent and thermal membrane regeneration methods

“…The PS turned darker during thermal oxidation and started to melt, with complete melting after 24 h. FTIR showed the emergence of a small new peak at wavenumber 1070 cm −1 after 8 h of heating, indicating the generation of primary alcohol (‐C‐O stretch). After 24 h of thermal oxidation, the peak became clearer, and three additional peaks appeared at wavenumbers 1720, 2800, and 2900 cm −1 , representing ketones stretch, aldehyde stretch, and alkane stretch, respectively (Bilkey et al, 2022). The results suggest that the chemical bonds of PS started to break after 8 h heating at 250°C and that the thermal degradation accelerated with extended heating time.…”