Ectopic lignification in primary cellulose-deficient cell walls of maize cell suspension cultures.
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.
Plant Physiology Laboratory, Faculty of Biological and Environmental Sciences, University of León, E-24071 León, Spain; Centre for Plant Biotechnology and Genomics (CBGP), Politechnical University of Madrid, E-28223 Madrid, Spain.
Hugo
H
Mélida
Asier
A
Largo-Gosens
Esther
E
Novo-Uzal
Rogelio
R
Santiago
Federico
F
Pomar
Pedro
P
García
Penélope
P
García-Angulo
José Luis
JL
Acebes
Jesús
J
Álvarez
Antonio
A
Encina
D001089:Arabinose / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000235:genetics; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D002482:Cellulose / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D008031:Lignin / Q000378:metabolism*; D009570:Nitriles / Q000494:pharmacology; D054883:Oxylipins / Q000378:metabolism; D010636:Phenols / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D017550:Spectroscopy, Fourier Transform Infrared; D013194:Staining and Labeling; D013535:Suspensions; D014990:Xylans / Q000378:metabolism; D014994:Xylose / Q000378:metabolism; D003313:Zea mays / Q000166:cytology* / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
D003517:Cyclopentanes; D009570:Nitriles; D054883:Oxylipins; D010636:Phenols; D011134:Polysaccharides; D013535:Suspensions; D014990:Xylans; C011006:jasmonic acid; D002482:Cellulose; D008031:Lignin; C085118:arabinoxylan; D014994:Xylose; D001089:Arabinose; D006861:Hydrogen Peroxide; C055869:dichlobanil; D020156:Salicylic Acid
Cellulose; DCB; dichlobenil; ectopic lignin; maize