Changes in the cell-wall polysaccharides of outer pericarp tissues of kiwifruit during development
Changes in the cell-wall polysaccharides of outer pericarp tissues of kiwifruit during development
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DOI：
10.1016/j.plaphy.2006.03.005
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发表时间：
2006-02-01
影响因子：
6.5
通讯作者：
Sakurai, Naoki
中科院分区：
文献类型：
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作者：
Li, Xinjun;Nakagawa, Naoki;Sakurai, Naoki
在发育过程中测定了猕猴桃（Actinidia deliciosa cv. Hayward）外果皮组织细胞壁中果胶、半纤维素和纤维素的变化。在壁多糖分级之前和之后，采用广泛的淀粉酶消化来去除可能的污染淀粉。用 α-淀粉酶和异淀粉酶或 DMSO 对粗制细胞壁进行初步处理。发现不足以从壁多糖中去除污染淀粉。 EDTA 和碱提取后，果胶和半纤维素级分再次用 α-淀粉酶和异淀粉酶的组合处理。主要果胶糖 Gal、Rha 和 Ara 的含量不受第一次和第二次淀粉酶消化的影响，在果实膨大早期（花后 8-12 周，WAA）显着下降，然后在 16-20 WAA 期间增加，最后在果实成熟期间（20-25 WAA）下降。果胶多糖的分子量在果实膨大期下降(8-16 WAA)，然后在果实成熟期变化不大。在果实膨大早期（8-12WAA）检测到的HC-1和HC-II级分中半纤维素的较高分子量成分在果实膨大后期（16WAA）被降解，但随后保持稳定在低得多的分子量直至果实成熟。在果实早期膨大和果实成熟期间，HC-II 级分中的木糖含量减少，这一观察结果与木葡聚糖 (XG) 含量一致。 XG 的凝胶渗透曲线显示，在 8-12 WAA 期间，较高分子量组分略有增加。但此后直到收获时间为止分子质量没有显着下降。在果实膨大至成熟期间，纤维素组分稳定增加，但HC-I和HC-II组分中的XG含量在这些阶段保持在较低水平。 HC-I 和 HC-II 级分的甲基化分析证实了半纤维素级分中 XG 的水平较低。表明猕猴桃外果皮中的果胶在果实膨大初期被降解，但XG在果实膨大和成熟过程中保持恒定。 (c) 2006 年爱思唯尔 SAS。版权所有。
Changes in pectin, hemicelluloses and cellulose in the cell walls of outer pericarp tissues of kiwifruit (Actinidia deliciosa cv. Hayward) were determined during development. An extensive amylase digestion was employed to remove possible contaminating starch before and after fractionation of wall polysaccharides. An initial treatment of crude cell walls with alpha-amylase and iso-amylase or DMSO. was found to be insufficient removing the contaminating starch from wall polysaccharides. After EDTA and alkaline extraction, the pectic and hemicellulose fractions were again treated with the combination of alpha-amylase and iso-amylase. The amounts of predominant pectic sugars Gal, Rha and Ara, unaffected by the first and second amylase digestion, decreased markedly during the early fruit enlargement (8-12 weeks after anthesis, WAA), then increased during 16-20 WAA, and finally declined during fruit maturity (20-25 WAA). The molecular-mass of pectic polysaccharides decreased during fruit enlargement (8-16 WAA), and then changed little during fruit maturity. The higher molecular-mass components of hemicelluloses in HC-1 and HC-II fractions detected at the early stage of fruit enlargement (8-12 WAA) were degraded at the late stage of fruit enlargement (16 WAA), but then remained stable at the much lower molecular-mass till fruit maturity. The amount of Xyl in the HC-II fraction decreased during the early fruit enlargement and fruit maturity, an observation that was consistent with xyloglucan (XG) content. The gel permeation profiles of XG showed a slight increase in higher molecular-mass components during 8-12 WAA. but thereafter there was no significant down-shift of molecular-mass until harvest time. The cellulose fraction increased steadily during fruit enlargement through maturity, but the XG contents in HC-I and HC-II fractions remained at a low level during these stages. Methylation analysis of HC-I and HC-II fractions confirmed the low level of XG in the hemicellulosic fractions. It was suggested that pectin in the outer pericarp of kiwifruit was degraded at the early stage of fruit enlargement, but XG remains constant during fruit enlargement and maturation. (c) 2006 Elsevier SAS. All rights reserved.