Comparison of light microscopy and spatially resolved Fourier transform infrared (FT-IR) microscopy in the examination of cell wall components of strawberries

Different chemical components and their location in strawberry achene, vasc ular bundles and cortical cell walls were studied by means of bright-field microscopy rising different staining systems and by Fourier transform infra red (FT-IR) microscopy and the two methods were compared. For bright-field microscopy: pectin, protein, lignin and cellulose were stained with specifi c staining systems. For FT-IR microscopy, the spectra of commercial pectin, protein, lignin and cellulose were measured in the 4000-700 cm(-1) region and compared to spectra obtained from the different strawberry tissues. Bot h methods showed that lignin was an important component of achene and vascu lar bundles, whereas the cortical cell walls contained mainly pectin and ce llulose in the middle lamella, and protein as deposits in the outer layer. The structure of all the cell walls was complicated and consisted of severa l components. The two methods used gave comparable results. (C)1998 Academi c Press.