Application of vibrational spectroscopy techniques to non-destructively monitor plant health and development

Abstract

Vibrational spectroscopy is a powerful analytical tool that is yet to be fully developed in plant science. Previously, such tools have been primarily applied to fixed or in vitro biological materials, which do not effectively encapsulate real-time physiological conditions of whole organisms. Coupled with multivariate analysis, this study examines the potential application of ATR-FTIR or Raman spectroscopy to determine spectral alterations indicative of healthy plant growth in leaf samples of Solanum lycopersicum. This was achieved in the absence of destructive effects on leaf tissues locally or on plant health systemically; additionally, autofluorescence was not a confounder. Feature extraction techniques including PCA-LDA were employed to examine variance within spectral datasets. In vivo measurements are able to successfully characterise key constituents of the leaf cuticle and cell wall, whilst qualifying leaf growth. Major alterations in carbohydrate and protein content of leaves were observed, correlating with known processes within leaf development from cell wall expansion to leaf senescence. These findings show that vibrational spectroscopy is an ideal technique for in vivo investigations in plant tissues.