Abstract We have investigated the cell wall polysaccharides of a commercially grown blocky-type red bell pepper (Capsicum annuum L. ‘Funky’) during on-plant growth and ripening, and after postharvest water loss. There was no evidence of substantial depolymerisation of cell wall pectic polysaccharides or hemicelluloses at any ripening stage. The onset of fruit ripening was accompanied by a slightly increased solubilisation of very high molecular weight polyuronides. Measurable polygalacturonase activity was absent, despite an endo-polygalacturonase mRNA being present as fruit turned red. The largest cell wall change was a substantial loss of galactose (primarily from Na2CO3-soluble rhamnogalacturonan-I) as green fruit approached full size, which could not be directly correlated with conventionally assayed β-galactosidase/galactanase activities. The majority of β-galactosidase/galactanase gene expression and enzyme activity was found in fully ripe fruit, although by this stage galactose loss was comparatively minimal. This suggests that the upregulation in activity has significance beyond wall rheology, or is vestigial. Severe water-stress applied to harvested ripe fruit did not result in any cell wall changes suggestive of cell wall breakdown, compared with cell walls of fruit stored under high humidity conditions. We conclude that this commercial line of bell pepper, which was bred for intensive glasshouse production, has wall characteristics that result in retention of typical crisp texture and extended postharvest storage life.

中文翻译：

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红甜椒（Capsicum annuum L.）在膨胀、成熟和采后失水过程中的细胞壁组成

摘要 我们研究了商业种植的块状红甜椒 (Capsicum annuum L. 'Funky') 在植株生长和成熟期间以及收获后失水后的细胞壁多糖。没有证据表明在任何成熟阶段细胞壁果胶多糖或半纤维素大量解聚。果实成熟的开始伴随着非常高分子量的多糖醛酸苷的溶解度略有增加。尽管在果实变红时存在内切多聚半乳糖醛酸酶 mRNA，但不存在可测量的多聚半乳糖醛酸酶活性。最大的细胞壁变化是半乳糖的大量损失（主要来自 Na2CO3 可溶性鼠李糖半乳糖醛酸聚糖-I），因为绿色果实接近全尺寸，这与常规测定的 β-半乳糖苷酶/半乳聚糖酶活性没有直接关系。大多数 β-半乳糖苷酶/半乳糖苷酶基因表达和酶活性在完全成熟的果实中被发现，尽管在这个阶段半乳糖损失相对较少。这表明活性的上调具有超出壁流变学的意义，或者是退化的。与在高湿度条件下储存的水果的细胞壁相比，对收获的成熟水果施加严重的水分胁迫不会导致任何细胞壁变化，表明细胞壁破裂。我们得出的结论是，这种为集中温室生产而培育的甜椒商业系列具有壁特性，可保留典型的脆质地并延长收获后的储存寿命。尽管到了这个阶段，半乳糖损失相对较少。这表明活性的上调具有超出壁流变学的意义，或者是退化的。与在高湿度条件下储存的水果的细胞壁相比，对收获的成熟水果施加严重的水分胁迫不会导致任何细胞壁变化，表明细胞壁破裂。我们得出的结论是，这种为集中温室生产而培育的甜椒商业系列具有壁特性，可保留典型的脆质地并延长收获后的储存寿命。尽管到了这个阶段，半乳糖损失相对较少。这表明活性的上调具有超出壁流变学的意义，或者是退化的。与在高湿度条件下储存的水果的细胞壁相比，对收获的成熟水果施加严重的水分胁迫不会导致任何细胞壁变化，表明细胞壁破裂。我们得出的结论是，这种为集中温室生产而培育的甜椒商业系列具有壁特性，可保留典型的脆质地并延长收获后的储存寿命。与储存在高湿度条件下的水果细胞壁相比。我们得出的结论是，这种为集中温室生产而培育的甜椒商业系列具有壁特性，可保留典型的脆质地并延长收获后的储存寿命。与储存在高湿度条件下的水果细胞壁相比。我们得出的结论是，这种为集中温室生产而培育的甜椒商业系列具有壁特性，可保留典型的脆质地并延长收获后的储存寿命。