TY - JOUR T1 - Structural imaging of native cryo-preserved secondary cell walls reveals presence of macrofibrils composed of cellulose, lignin and xylan JF - bioRxiv DO - 10.1101/648360 SP - 648360 AU - Jan J. Lyczakowski AU - Matthieu Bourdon AU - Oliver M. Terrett AU - Ykä Helariutta AU - Raymond Wightman AU - Paul Dupree Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/05/24/648360.abstract N2 - The woody secondary cell walls of plants are the largest repository of renewable carbon biopolymers on the planet. These walls are made principally from cellulose and hemicelluloses and are impregnated with lignin. Despite their importance as the main load bearing structure for plant growth, as well as their industrial importance as both a material and energy source, the precise arrangement of these constituents within the cell wall is not yet fully understood. We have adapted low temperature scanning electron microscopy (cryo-SEM) for imaging the nanoscale architecture of angiosperm and gymnosperm cell walls in their native hydrated state. Our work confirms that cell wall macrofibrils, cylindrical structures with a diameter exceeding 10 nm, are a common feature of the native hardwood and softwood samples. We have observed these same structures in Arabidopsis thaliana secondary cell walls, enabling macrofibrils to be compared between mutant lines that are perturbed in cellulose, hemicellulose and lignin formation. Our analysis indicates that the macrofibrils in Arabidopsis cell walls are composed, at least partially, of cellulose, xylan and lignin. This study is a useful additional approach for investigating the native nanoscale architecture and composition of hardwood and softwood secondary cell walls and demonstrates the applicability of Arabidopsis genetic resources to relate fibril structure with wall composition and biosynthesis.1Done dimensionalAFMatomic force microscopy CesA – Cellulosesynthase cryo-SEMlow temperature scanning electronmicroscopy FE-SEMfield emission scanning electron microscopyFT-IRFourier-transform infrared spectroscopyGGMgalactoglucomannanHe-ionHelium ionIRXirregular xylem[Me]GlcAmethylated and unmethylated form of glucuronic acidNMRnuclear magnetic resonanceSANSsmall angle neutron scatteringTEMtransmission electron microscopyWAXSwide angle x-ray scattering ER -