Deconstructing a Plant Macromolecular Assembly: Chemical Architecture, Molecular Flexibility, And Mechanical Performance of Natural and Engineered Potato Suberins

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• 作者：Olga Serra ; Subhasish Chatterjee ; Merc猫 Figueras ; Marisa Molinas ; Ruth E. Stark
• 刊名：Biomacromolecules
• 出版年：2014
• 出版时间：March 10, 2014
• 年：2014
• 卷：15
• 期：3
• 页码：799-811
• 全文大小：773K
• 年卷期：v.15,no.3(March 10, 2014)
• ISSN：1526-4602

文摘

Periderms present in plant barks are essential protective barriers to water diffusion, mechanical breakdown, and pathogenic invasion. They consist of densely packed layers of dead cells with cell walls that are embedded with suberin. Understanding the interplay of molecular structure, dynamics, and biomechanics in these cell wall-associated insoluble amorphous polymeric assemblies presents substantial investigative challenges. We report solid-state NMR coordinated with FT-IR and tensile strength measurements for periderms from native and wound-healing potatoes and from potatoes with genetically modified suberins. The analyses include the intact suberin aromatic鈥揳liphatic polymer and cell-wall polysaccharides, previously reported soluble depolymerized transmethylation products, and undegraded residues including suberan. Wound-healing suberized potato cell walls, which are 2 orders of magnitude more permeable to water than native periderms, display a strikingly enhanced hydrophilic鈥揾ydrophobic balance, a degradation-resistant aromatic domain, and flexibility suggestive of an altered supramolecular organization in the periderm. Suppression of ferulate ester formation in suberin and associated wax remodels the periderm with more flexible aliphatic chains and abundant aromatic constituents that can resist transesterification, attenuates cooperative hydroxyfatty acid motions, and produces a mechanically compromised and highly water-permeable periderm.