FT-Raman spectroscopy as a tool in evaluation the response of plants to drought stress

Abstract

The aim of study was to evaluate the usefulness of FT-Raman spectroscopy in assessing stress-induced metabolic changes in plants. 20-d-old optimally watered plants of soybean were exposed to drought. Metabolic changes in optimally watered and drought-stressed plants were monitored using FT-Raman spectroscopy. In parallel, analyses were carried out of fatty acid composition and pigment content using analytical methods. These compounds are associated with the response of plants to environmental stress. While fatty acid assays in study were inconclusive, the pigment content analysis gave promising results. FT-Raman experiment demonstrated a decrease in carotenoid content in leaf, as a result of drought, which was confirmed by spectrophotometric analysis. In addition to the analysis of aforementioned compounds, FT-Raman spectroscopy allowed the simultaneous observation of a wider spectrum of compounds scattering the radiation in the leaves tested, and their subsequent comparative analysis. The impact of drought on metabolism of soybean was clearly visible on spectra and confirmed using cluster analysis. The technical problem of the influence of leaf water content on measurements, which appeared in studies, will be discussed. To conclude, FT-Raman spectroscopy may be a good complement to other noninvasive methods, e.g., fluorescent methods, in assessing the stress-induced damage of crops.

Insight into plant cell wall chemistry and structure by combination of multiphoton microscopy with Raman imaging

“…In order to analyze the spatial distribution of the complex mixture of compounds in the plant tissue, we utilized multivariate methods . In Figure , we show the results of multivariate analyses of a Raman map of a sorghum root section, using the whole measured spectral range of 350 to 1800 cm −1 .…”

Deacclimation of Winter Oilseed Rape—Insight into Physiological Changes

“…FT-Raman spectroscopy is a non-invasive technique, which is useful for identifying the chemical composition of living plant tissue [87][88][89][90]. Although it has recently been used to study the effects of abiotic and biotic stresses on plants [91,92], in the presented studies, this method was used to determine the chemical composition of plant leaves that had been subjected to cold acclimation and deacclimation periods for the first time. Because the concentration of the compounds in leaves is directly correlated with the intensity of the bands that are observed on the spectra [93], the results for oilseed rape leaves showed, among others, the significant differences in the content of carotenoids and chlorophylls (Figure 7A,B).…”

Time‐resolved assessment of drying plants by Brillouin and Raman spectroscopies

“…The spectral area of 1525‐cm −1 peak, which is attributed to C═C stretching vibrations in α or/and β carotenes, increased by up to 70%. Two Raman active vibrations of 1,157 and 1,190 cm −1 (the latter can be attributed to disaccharides), reported at 1,188 cm −1 , raised by 50% upon the first 12 hr of drying and loss of 35% mass, but their area decreased after 24 hr of drying, shrinking by 28–38% of the original value in the end of the experiment.…”

“…Optical imaging methods are considered as promising techniques for providing more information on the plant health state. In one of the previous studies, fluorescence‐emission Brillouin imaging has been used to assess the mechanical properties of extracellular matrix of living onion peels, and in the other study, the Fourier transform‐Raman spectroscopy measurements have been performed on living and drying soybean leaves . So, the samples in the previous research were different for Brillouin and Raman spectroscopies.…”