Infrared imaging of sunflower and maize root anatomy.

Synchrotron radiation infrared microspectroscopy (SR-IMS) permits the direct analysis of plant cell-wall architecture at the cellular level in situ, combining spatially localized information and chemical information from IR absorbances to produce a chemical map that can be linked to a particular morphology or functional group. This study demonstrated the use of SR-IMS to probe biopolymers, such as cellulose, lignin, and proteins, in the root tissue of hydroponically grown sunflower and maize plants. Principal components analysis (PCA) was employed to reveal the major spectral variance between maize and sunflower plant tissues. The use of PCA showed distinct separation of maize and sunflower samples using the IR spectra of the epidermis and xylem. The infrared band at 1635 cm(-1), representing hydrocinnamic acid in (H type) lignin, provided a conclusive means of distinguishing between maize and sunflower plant tissues.