Magic-Angle Spinning NMR Studies of Cell Wall Bound Aromatic-Aliphatic Biopolyesters Associated with Strengthening of Intercellular Adhesion in Potato (Solanum tuberosum L.) Tuber Parenchyma

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• 作者：Bingwu Yu ; G. Vengadesan ; Hsin Wang ; Liana Jashi ; Tatiana Yefremov ; Shiying Tian ; Victor Gaba ; Ilan Shomer ; and Ruth E. Stark
• 刊名：Biomacromolecules
• 出版年：2006
• 出版时间：March 2006
• 年：2006
• 卷：7
• 期：3
• 页码：937 - 944
• 全文大小：203K
• 年卷期：v.7,no.3(March 2006)
• ISSN：1526-4602

文摘

Intercellular adhesion strengthening, a phenomenon that compromises the texture and the edible quality of potatoes(Solanum tuberosum L.), has been induced reproducibly by exposure to low-pH acetic acid solutions under tissueculture conditions. The resulting parenchyma tissues have been examined by solid-state nuclear magnetic resonance(NMR) in order to characterize the biopolymer(s) thought to be associated with this syndrome. Cross polarization-magic angle spinning (CPMAS) ¹³C NMR has been used to establish the presence of a polyphenol-suberin-likearomatic-aliphatic polyester within an abundant cell wall polysaccharide matrix in potato tubers that exhibithardening due to strengthened intercellular adhesion. Dipolar dephasing and CP chemical shift anisotropyexperiments suggest that the aromatic domain is composed primarily of guaiacyl and sinapyl groups.Two-dimensional wide-line separation experiments show that the biopolymer associated with parenchyma hardeningcontains rigid polysaccharide cell walls and mobile aliphatic long-chain fatty acids; ¹H spin diffusion experimentsshow that these flexible aliphatic chains are proximal to both the phenolics and a subpopulation of the cell wallpolysaccharides. Finally, high-resolution MAS NMR of parenchyma samples swelled in DMSO in conjunctionwith two-dimensional through-bond and through-space NMR spectroscopy provides evidence for covalent linkagesamong the polysaccharide, phenolic, and aliphatic domains of the intercellular adhesion-strengthening biopolymerin potato parenchyma tissue.