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

PLoS One. 2021 May 5;16(5):e0250650. doi: 10.1371/journal.pone.0250650. eCollection 2021.

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.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cell Wall / metabolism*
  • Glucans / metabolism*
  • Onions / cytology*
  • Pectins / metabolism*
  • Plant Epidermis / cytology*
  • Protein Transport
  • Spectrum Analysis, Raman*
  • Xylans / metabolism*

Substances

  • Glucans
  • Xylans
  • xyloglucan
  • Pectins

Grants and funding

QH, OZ and CY received funding from The National Institute of Food and Agriculture (NIFA) [grant number: 2016-67021-25034] for this work. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.