Fourier Transform InfraRed (FTIR) spectroscopy is a powerful and rapid technique for analysing cell wall components and putative cross-links, which is able to non-destructively recognize polymers and functional groups and provide abundant information about their in muro organization. FTIR spectroscopy has been reported to be a useful tool for monitoring cell wall changes occurring in muro as a result of various factors, such as growth and development processes, mutations or biotic and abiotic stresses. This mini-review examines the use of FTIR spectroscopy in conjunction with multivariate analyses to monitor cell wall changes related to (1) the exposure of diverse plant materials to cellulose biosynthesis inhibitors (CBIs), and (2) the habituation/dehabituation of plant cell cultures to this kind of herbicides. The spectra analyses show differences not only regarding the inhibitor, but also regarding how long cells have been growing in its presence.

Maize (Zea mays L.) suspension‐cultured cells with up to 70% less cellulose were obtained by stepwise habituation to dichlobenil (DCB), a cellulose biosynthesis inhibitor. Cellulose deficiency was accompanied by marked changes in cell wall matrix polysaccharides and phenolics as revealed by Fourier transform infrared (FTIR) spectroscopy. Cell wall compositional analysis indicated that the cellulose‐deficient cell walls showed an enhancement of highly branched and cross‐linked arabinoxylans, as well as an increased content in ferulic acid, diferulates and p‐coumaric acid, and the presence of a polymer that stained positive for phloroglucinol. In accordance with this, cellulose‐deficient cell walls showed a fivefold increase in Klason‐type lignin. Thioacidolysis/GC‐MS analysis of cellulose‐deficient cell walls indicated the presence of a lignin‐like polymer with a Syringyl/Guaiacyl ratio of 1.45, which differed from the sensu stricto stress‐related lignin that arose in response to short‐term DCB‐treatments. Gene expression analysis of these cells indicated an overexpression of genes specific for the biosynthesis of monolignol units of lignin. A study of stress signaling pathways revealed an overexpression of some of the jasmonate signaling pathway genes, which might trigger ectopic lignification in response to cell wall integrity disruptions. In summary, the structural plasticity of primary cell walls is proven, since a lignification process is possible in response to cellulose impoverishment.