Surface-enhanced Raman spectroscopic chemical imaging reveals distribution of pectin and its co-localization with xyloglucan inside onion epidermal cell wall

Abstract

The primary plant cell wall is a complex matrix composed of interconnected polysaccharides including cellulose, hemicellulose, and pectin. Changes of this dynamic polysaccharide system play a critical role during plant cell development and differentiation. A better understanding of cell wall architectures can provide insight into the plant cell development. In this study, a Raman spectroscopic imaging approach was developed to visualize the distribution of plant cell wall polysaccharides. In this approach, Surface-enhanced Raman scattering (SERS through self-assembled silver nanoparticles) was combined with Raman labels (4-Aminothiophenol. 4ATP) and targeted enzymatic hydrolysis to improve the sensitivity, specificity, and throughput of the Raman imaging technique, and to reveal the distribution of pectin and its co-localization with xyloglucan inside onion epidermal cell (OEC) wall. This technique significantly decreased the required spectral acquisition time. The resulted Raman spectra showed a high Raman signal. The resulted Raman images successfully revealed and characterized the pectin distribution and its co-localization pattern with xyloglucan in OEC wall.

Broad Specific Xyloglucan:Xyloglucosyl Transferases Are Formidable Players in the Re-Modelling of Plant Cell Wall Structures

“…On the other hand, Raman spectroscopy and surface-enhanced Raman spectroscopic chemical imaging allowed investigating the mutual distribution and co-localisation of CW polysaccharides, such as pectin and XGs in, for example, onion cells [108]. Further, Felhofer and co-workers [109] described how CW thickening indentations were formed in primary CWs in algae at exactly defined areas, specifically where pectins and XGs co-localised, while in the secondary CWs, crystalline cellulose dominated in thickening areas.…”

Deciphering biomolecular complexities: the indispensable role of surface-enhanced Raman spectroscopy in modern bioanalytical research

“…7A). Such insights are instrumental in strategizing protective measures against photodamage, with pro- 55 nounced implications for agronomic research. Additionally, Jiang et al embarked on a journey to explore the SERS spectral characteristics of cholesterol, aiming to decipher its spatial orientations within cellular membranes 60 (see Fig.…”

“…53 with permission from Elsevier, Copyright 2022. (C) Schematic diagram of SERS used for Raman imaging of protein-specific glycosylation on cell surfaces; 54 (D) schematic diagram of SERS used to study the distribution of polysaccharides on the cell walls of plants 55.…”

Natural polymers in wound healing: From academic studies to commercial products

“…Pec is found in all primary and secondary cell walls of terrestrial plants. The primary cell wall of dicotyledonous plants is composed of cellulose microfibrils coated with xyloglucan, which are dispersed in a matrix of pectin polysaccharides and form the middle lamella 136 . Pec is mostly extracted from the cell walls of apples, pears, etc 137 .…”

“…The primary cell wall of dicotyledonous plants is composed of cellulose microfibrils coated with xyloglucan, which are dispersed in a matrix of pectin polysaccharides and form the middle lamella. 136 Pec is mostly extracted from the cell walls of apples, pears, etc. 137 Pec contains 1,4-linked α-D-galacturonic acid residues (approximately 70%), which consists of three major classes: homogalacturonan (HG), rhamnogalacturonan I (RG-I), and rhamnogalacturonan II (RG-II) (Figure 5).…”