title: Aluminium effects on mechanical properties of cell wall analogues.
abstract: Aluminium (Al) toxicity adversely impacts plant productivity in acid soils by restricting root growth and although several mechanisms are involved the physiological basis of decreased root elongation remains unclear. Understanding the primary mechanisms of Al rhizotoxicity is hindered due to the rapid effects of soluble Al on root growth and the close proximity of many cellular components within the cell wall, plasma membrane, cytosol and nucleus with which Al may react. To overcome some of these difficulties, we report on a novel method for investigating Al interactions with Komagataeibacter xylinus bacterial cellulose (BC)-pectin composites as cell wall analogues. The growth of K. xylinus in the presence of various plant cell wall polysaccharides, such as pectin, has provided a unique in vitro model system with which to investigate the interactions of Al with plant cell wall polysaccharides. The BC-pectin composites reacted in a similar way with Al as do plant cell walls, providing insights into the effects of Al on the mechanical properties of the BC-pectin composites as cell wall analogues. Our findings indicated that there were no significant effects of Al (4-160 μM) on the tensile stress, tensile strain or Young's modulus of the composites. This finding was consistent with cellulose, not pectin, being the major load bearing component in BC-pectin composites, as is also the case in plant cell walls.
authors.affiliation: The University of Queensland, School of Agriculture and Food Sciences, Brisbane, Queensland, 4072, Australia.
authors.forename: Brigid A
authors.initials: BA
authors.lastname: McKenna
authors.affiliation: The University of Queensland, School of Agriculture and Food Sciences, Brisbane, Queensland, 4072, Australia.
authors.forename: J Bernhard
authors.initials: JB
authors.lastname: Wehr
authors.affiliation: The University of Queensland, ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland, 4072, Australia.
authors.forename: Deirdre
authors.initials: D
authors.lastname: Mikkelsen
authors.affiliation: The University of Queensland, School of Agriculture and Food Sciences, Brisbane, Queensland, 4072, Australia.
authors.forename: F Pax C
authors.initials: FP
authors.lastname: Blamey
authors.affiliation: The University of Queensland, School of Agriculture and Food Sciences, Brisbane, Queensland, 4072, Australia.
authors.forename: Neal W
authors.initials: NW
authors.lastname: Menzies
mesh_terms: D000535:Aluminum / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects; D002473:Cell Wall / Q000187:drug effects*; D002482:Cellulose / Q000378:metabolism; D041822:Gluconacetobacter xylinus / Q000378:metabolism; D066298:In Vitro Techniques; D010368:Pectins / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects; D013718:Tensile Strength / Q000187:drug effects*
chemical_list: D010368:Pectins; D002482:Cellulose; D000535:Aluminum