Principles and Applications of Vibrational Spectroscopic Imaging in Plant Science: A Review

Abstract

Detailed knowledge about plant chemical constituents and their distributions from organ level to sub-cellular level is of critical interest to basic and applied sciences. Spectral imaging techniques offer unparalleled advantages in that regard. The core advantage of these technologies is that they acquire spatially distributed semi-quantitative information of high specificity towards chemical constituents of plants. This forms invaluable asset in the studies on plant biochemical and structural features. In certain applications, non-invasive analysis is possible. The information harvested through spectral imaging can be used for exploration of plant biochemistry, physiology, metabolism, classification, and phenotyping among others, with significant gains for basic and applied research. This article aims to present a general perspective about vibrational spectral imaging/micro-spectroscopy in the context of plant research. Within the scope of this review are infrared (IR), near-infrared (NIR) and Raman imaging techniques. To better expose the potential and limitations of these techniques, fluorescence imaging is briefly overviewed as a method relatively less flexible but particularly powerful for the investigation of photosynthesis. Included is a brief introduction to the physical, instrumental, and data-analytical background essential for the applications of imaging techniques. The applications are discussed on the basis of recent literature.

Surface-Enhanced Raman Scattering Spectroscopy Combined With Chemical Imaging Analysis for Detecting Apple Valsa Canker at an Early Stage

“…As shown in Figure 6, many SERS peaks can be clearly observed. In detail, the peaks at 319, 957, 1,026, 1,165, 1,242, and 1,325 cm −1 were indicators of cellulose, corresponding to C-C-C or C-O-C skeletal bending (Szymanska et al, 2011), C-C or C-O stretching vibration (Beć et al, 2020), C-C or C-O stretching vibration (Beć et al, 2020), H-C-C or H-C-O skeletal bending (Edwards et al, 1997), C = O stretching vibration (Beć et al, 2020), and C-H bending vibration (Edwards et al, 1997), respectively. The peaks at 625, 731, 1,599, and 2,939 cm −1 were indicators of lignin, corresponding to skeletal bending (Agarwal et al, 2011), skeletal bending (Agarwal et al, 2011), C-C aromatic ring (Agarwal, 2006), and C-H asymmetric stretching vibration (Gierlinger and Schwanninger, 2007), respectively.…”

Surface Enhanced Raman Scattering (SERS) Spectroscopy Combined With Chemical Imaging Analysis For The Early Detection of Apple Valsa Canker

“…4, many SERS peaks can be clearly observed. In detail, the peaks at 319, 957, 1026, [37], and C-H bending vibration [38]. The peaks at 625, 731, 1599, and 2939 cm − 1 were indicators of lignin, corresponding to skeletal bending [39], skeletal bending [39], C-C aromatic ring [40], and C-H asymmetric stretching vibration [41].…”

A Fast, Straightforward and Inexpensive Method for the Authentication of Baijiu Spirit Samples by Fluorescence Spectroscopy

“…Fluorescence spectroscopy is also known to be 1-3 orders of magnitude more sensitive than UV-visible spectroscopy. One clear disadvantage to using fluorescence spectroscopy is the inability to obtain the chemical profile of the sample; an advantage is the interpretation in the differences of the fluorescence spectra is much less systematic than other techniques such as infrared spectroscopy, NMR, Raman, and mass spectral data [14].…”