Nunan KJ, Sims IM, Bacic A, Robinson SP, Fincher GB
Department of Plant Science, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia (K.J.N., G.B.F.).
Plant Physiol. 1998 Nov;118(3):783-92. doi: 10.1104/pp.118.3.783.
Cell walls were isolated from the mesocarp of grape (Vitis vinifera L.) berries at developmental stages from before veraison through to the final ripe berry. Fluorescence and light microscopy of intact berries revealed no measurable change in cell wall thickness as the mesocarp cells expanded in the ripening fruit. Isolated walls were analyzed for their protein contents and amino acid compositions, and for changes in the composition and solubility of constituent polysaccharides during development. Increases in protein content after veraison were accompanied by an approximate 3-fold increase in hydroxyproline content. The type I arabinogalactan content of the pectic polysaccharides decreased from approximately 20 mol % of total wall polysaccharides to about 4 mol % of wall polysaccharides during berry development. Galacturonan content increased from 26 to 41 mol % of wall polysaccharides, and the galacturonan appeared to become more soluble as ripening progressed. After an initial decrease in the degree of esterification of pectic polysaccharides, no further changes were observed nor were there large variations in cellulose (30-35 mol % of wall polysaccharides) or xyloglucan (approximately 10 mol % of wall polysaccharides) contents. Overall, the results indicate that no major changes in cell wall polysaccharide composition occurred during softening of ripening grape berries, but that significant modification of specific polysaccharide components were observed, together with large changes in protein composition.
从葡萄（欧亚种葡萄）浆果的中果皮中分离细胞壁，这些浆果处于从转色期前到最终成熟的发育阶段。对完整浆果进行荧光和光学显微镜观察发现，随着成熟果实中果皮细胞的扩张，细胞壁厚度没有可测量的变化。对分离得到的细胞壁进行蛋白质含量和氨基酸组成分析，并分析发育过程中组成多糖的组成和溶解性变化。转色期后蛋白质含量增加，同时羟脯氨酸含量增加了约3倍。在浆果发育过程中，果胶多糖中I型阿拉伯半乳聚糖的含量从约占总细胞壁多糖的20摩尔%降至约占细胞壁多糖的4摩尔%。半乳糖醛酸聚糖含量从占细胞壁多糖的26摩尔%增加到41摩尔%，并且随着成熟进程，半乳糖醛酸聚糖似乎变得更易溶解。果胶多糖的酯化程度最初下降后，未观察到进一步变化，纤维素（占细胞壁多糖的30 - 35摩尔%）或木葡聚糖（约占细胞壁多糖的10摩尔%）含量也没有大的变化。总体而言，结果表明，在成熟葡萄浆果软化过程中，细胞壁多糖组成没有发生重大变化，但观察到特定多糖成分有显著改变，同时蛋白质组成也有很大变化。
