Cell wall metabolism during maturation, ripening and senescence of peach fruit
Cell wall metabolism during maturation, ripening and senescence of peach fruit
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DOI：
10.1093/jxb/erh227
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发表时间：
2004-09-01
影响因子：
6.9
通讯作者：
Labavitch, JM
中科院分区：
文献类型：
--
作者：
Brummell, DA;Dal Cin, V;Labavitch, JM
以桃（Prunus persica L.）让它在树上成熟软化的三个阶段，其中第一个开始之前完成的果肉颜色的变化和乙烯释放的增加。软化在年轻成熟的水果，成熟之前，与松散和紧密连接到纤维素和损失的Gal从所有细胞壁组分的基质聚糖的解聚。在成熟开始后，但在熔化阶段之前，软化与基质聚糖的持续、渐进解聚有关。大量的损失，阿糖胞苷从松散结合的基质聚糖部分观察到，可能从侧链的葡糖醛酸阿拉伯木聚糖，果胶，或可能的阿拉伯半乳聚糖蛋白牢固地结合到墙壁和溶解在这种提取物。在此期间，当软化已经很好地进行时，也发生了增加的多糖醛酸苷的增溶。广泛软化的熔化期的标志是大量解聚的松散和紧密结合的基质聚糖，包括从后者的Ara的损失，增加基质聚糖的可提取性，和显着解聚的螯合剂可溶性polyuronides，在衰老过程中继续。因此，螯合剂可溶性polyuronides的解聚发生后，在其增溶的增加。在外切和内切多聚半乳糖醛酸酶（EC www.example.com; EC www.example.com）、果胶甲基酯酶（EC www.example.com）、内切-1，4-β-葡聚糖酶（EC www.example.com）、内切-1，4-β-甘露聚糖酶（EC www.example.com）、α-阿拉伯糖苷酶（EC www.example.com）和β-半乳糖苷酶（EC www.example.com）的活性中观察到与成熟相关的增加，但酶之间增加的时间和程度不同，不一定与乙烯释放有关。桃果实软化是一个连续的过程，与果实发育过程中基质聚糖的解聚密切相关。然而，也发生了许多其他细胞壁的变化，如特定聚合物的去糖基化和螯合剂可溶性多糖醛酸苷的溶解和解聚，但这些都是短暂的，只发生在软化过程的特定阶段。桃的果实软化和其他质地变化似乎有许多阶段，每个阶段都涉及不同的细胞壁修饰。
Cell wall changes were examined in fruit of a melting flesh peach (Prunus persica L.) allowed to ripen on the tree. Three phases to softening were noted, the first of which began prior to the completion of flesh colour change and an increase in ethylene evolution. Softening in young mature fruit, prior to ripening, was associated with a depolymerization of matrix glycans both loosely and tightly attached to cellulose and a loss of Gal from all cell wall fractions. After the initiation of ripening, but before the melting stage, softening was associated with continuing, progressive depolymerization of matrix glycans. A massive loss of Ara from the loosely bound matrix glycan fraction was observed, probably from side chains of glucuronoarabinoxylan, pectin, or possibly arabinogalactan protein firmly bound into the wall and solubilized in this extract. An increase in the solubilization of polyuronides also occurred during this period, when softening was already well advanced. The extensive softening of the melting period was marked by substantial depolymerization of both loosely and tightly bound matrix glycans, including a loss of Ara from the latter, an increase in matrix glycan extractability, and a dramatic depolymerization of chelator-soluble polyuronides which continued during senescence. Depolymerization of chelator-soluble polyuronides thus occurred substantially after the increase in their solubilization. Ripening-related increases were observed in the activities of exo- and endo-polygalacturonase (EC 3.2.1.67; EC 3.2.1.15), pectin methylesterase (EC 3.1.1.11), endo-1,4-beta-glucanase (EC 3.2.1.4), endo-1,4-beta-mannanase (EC 3.2.1.78), alpha-arabinosidase (EC 3.2.1.55), and beta-galactosidase (EC 3.2.1.23), but the timing and extent of the increases differed between enzymes and was not necessarily related to ethylene evolution. Fruit softening in peach is a continuous process and correlated closely with the depolymerization of matrix glycans, which proceeded throughout development. However, numerous other cell wall changes also took place, such as the deglycosylation of particular polymers and the solubilization and depolymerization of chelator-soluble polyuronides, but these were transient and occurred only at specific phases of the softening process. Fruit softening and other textural changes in peach appear to have a number of stages, each involving a different set of cell wall modifications.