Changes in activities and gene expression of enzymes associated with cell wall modification in peels of hot water treated bananas
Changes in activities and gene expression of enzymes associated with cell wall modification in peels of hot water treated bananas
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DOI：
10.1016/j.scienta.2012.05.006
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发表时间：
2012-07-13
影响因子：
4.3
通讯作者：
Seraypheap, Kanogwan
中科院分区：
文献类型：
--
作者：
Amnuaysin, Nuankamol;Jones, Michelle L.;Seraypheap, Kanogwan
果实软化是成熟过程中的一个重要事件，它影响果实品质和采后货架期。细胞壁降解酶被认为是导致果实（果肉和果皮）细胞壁分解和质地变化的主要因素。为了阐明热水处理（50℃，10分钟）对‘红芒’香蕉软化的影响，对果皮的硬度、细胞壁降解酶的活性以及相关基因的表达进行了研究。香蕉果实的硬度在整个贮藏期间都有所下降；然而，在25℃贮藏期间，与对照果实相比，热水处理的果实硬度下降有所延迟。用热水处理完整的果实降低了果皮中果胶裂解酶（PL）和β - 半乳糖苷酶（β - Gal）的活性，也减少了它们的mRNA（分别为MaPL1和MaGAL）的积累。多聚半乳糖醛酸酶（PG）的酶活性受到热处理的抑制，MaPG1表达的增加也被延迟。热水处理对果胶甲酯酶（PME）或β - 1,3 - 葡聚糖酶（Glu）影响较小。处理后，果皮中果胶甲酯酶活性降低，但随后又恢复到与对照果实相似的水平。果胶甲酯酶活性在贮藏期间有所变化，且与MaPME1表达相关性不强。处理果实和对照果实之间的葡聚糖酶活性或MaGLU表达没有显著差异。采后热水处理可有效延迟‘红芒’香蕉的软化，并降低果皮中一些与细胞壁修饰相关的酶的活性和基因表达。（c）2012爱思唯尔有限公司。保留所有权利。
Fruit softening is an important event during ripening that affects quality and postharvest shelf life. Cell wall degrading enzymes are considered to be the main factor responsible for cell wall disassembly and texture changes in fruit, both pulp and peel. To elucidate the effect of hot water treatment (HWT, 50 degrees C, 10 min) on the softening of 'Hom Thong' banana, firmness, the activities of cell wall degrading enzymes, and the expression of related genes were investigated in the peel. The firmness of banana fruit decreased throughout the storage period; however, the decrease in firmness was delayed in hot water treated fruit as compare to control fruit during storage at 25 degrees C. Treatment of intact fruit with hot water reduced activities of pectate lyase (PL) and beta-galactosidase (beta-Gal) in the peel, and also decreased the accumulation of their mRNAs (MaPL1 and MaGAL, respectively). Polygalacturonase (PG) enzyme activity was inhibited by heat treatment, and the increase in MaPG1 expression was delayed. HWT had little effect on pectin methylesterase (PME) or beta-1,3 glucanase (Glu). After treatment, reduced PME activity was measured in the peels, but activity returned to levels similar to that of control fruit. PME activity varied during storage and did not correlate well with MaPME1 expression. There was no significant difference in Glu enzyme activity or MaGLU expression between treated and control fruit. Postharvest HWT was effective in delaying softening of 'Hom Thong' banana and reduced activities and gene expression of some enzymes associated with cell wall modification in the peel. (c) 2012 Elsevier B.V. All rights reserved.