Molecular cloning and characterization of a ripening-induced polygalacturonase related to papaya fruit softening
Molecular cloning and characterization of a ripening-induced polygalacturonase related to papaya fruit softening
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DOI：
10.1016/j.plaphy.2009.08.002
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发表时间：
2009-11-01
影响因子：
6.5
通讯作者：
Oliveira do Nascimento, Joao Roberto
中科院分区：
文献类型：
--
作者：
Fabi, Joao Paulo;Cordenunsi, Beatriz Rosana;Oliveira do Nascimento, Joao Roberto
果肉软化是番木瓜果实成熟过程中最显著的变化之一，是造成果实采后损失的主要原因。虽然细胞壁catalysts有重大影响，木瓜果实，在这一过程中所涉及的基因产物的质量信息是有限的。从番木瓜果肉中分离出一个全长多聚半乳糖醛酸酶cDNA（cpPG），并研究其在正常成熟和乙烯诱导成熟过程中以及果实暴露于1-MCP后的基因表达和酶活性。Northern-blot分析表明，cpPG转录强烈诱导成熟过程中，是高度乙烯依赖性。cpPG转录本的积累受酶活性的影响，与果肉硬度呈负相关。初步的二氧化硅分析的cpPG基因组序列显示，在启动子区域，可能有助于解释植物激素和非生物胁迫对番木瓜果实硬度的影响，推定的监管基序的发生。这种新分离的cpPG是一个重要的候选人的功能特性和操纵，以控制在番木瓜成熟过程中的果肉软化。(C)2009年Elsevier Masson SAS。All rights reserved.
Pulp softening is one of the most remarkable changes during ripening of papaya (Carica papaya) fruit and it is a major cause for post-harvest losses. Although cell wall catabolism has a major influence on papaya fruit, quality information on the gene products involved in this process is limited. A full-length polygalacturonase cDNA (cpPG) was isolated from papaya pulp and used to study gene expression and enzyme activity during normal and ethylene-induced ripening and after exposure of the fruit to 1-MCP. Northern-blot analysis demonstrated that cpPG transcription was strongly induced during ripening and was highly ethylene-dependent. The accumulation of cpPG transcript was paralleled by enzyme activity, and inversely correlated to the pulp firmness. Preliminary in silica analysis of the cpPG genomic sequence revealed the occurrence of putative regulatory motifs in the promoter region that may help to explain the effects of plant hormones and non-abiotic stresses on papaya fruit firmness. This newly isolated cpPG is an important candidate for functional characterization and manipulation to control the process of pulp softening during papaya ripening. (C) 2009 Elsevier Masson SAS. All rights reserved.