Fourier transform infrared (FT-IR) microspectroscopy was applied to three distinct types of plant tissue. Reflectance microspectroscopy of nutshells highlighted the differences between the chemistries of the inner and outer surfaces and the tissue as a whole. The outer surfaces were suberized, while the inner surfaces contained absorbances indicative of lignin or tannins or both. Transmission microspectroscopy was used to follow the changes in cell wall structure and composition of flax epidermal cells during development and showed that initial development was accompanied by suberin and lignin deposition, which was followed by polysaccharide deposition characteristic of secondary cell wall formation. These results were compared with those obtained from bamboo. Transmission microspectroscopy was also used to study the infection of potato tubers by Erwinia carotovora ssp. carotovora in aerobic and anaerobic conditions. The spectra suggested that both infective conditions produced cell wall degradation, whereas anaerobic infection was accompanied by extensive breakdown of starch and plasma membrane.
Derek Stewart, "Fourier Transform Infrared Microspectroscopy of Plant Tissues," Appl. Spectrosc. 50, 357-365 (1996)