Maize (Zea mays L.) suspension-cultured cells with
up to 70% less celluloseQ1 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 cellulosedeficient
cell walls showed an enhancement of highly
branched and cross-linked arabinoxylans, as well as an
increased content in ferulic acid, diferulates and pcoumaric
acid, and the presence of a polymer that stained
positive for phloroglucinol. In accordance with this, cellulosedeficient
cell walls showed a fivefold increase in Klasontype
lignin. Thioacidolysis/GC-MS analysis of cellulosedeficient
cell walls indicated the presence of a ligninlike
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
