molecular analysis of mechanism of fruit ripening and softening in pears

梨果实成熟软化机理的分子分析

基本信息

批准号：
11660032
负责人：
KUBO Yasutaka
金额：
$ 2.3万
依托单位：
OKAYAMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11660032/
关键词：
Pear Fruit softening Fruit Ripening Ethylene Expansin Polygalacturonase Gene expression 成熟

项目摘要

In order to establish physiological base of postharvest technology for extended shelf life with better quality, we investigated the mechanism of fruit ripening and softening at molecular level. We isolated ethylene biosynthetic gene (four isogenes for ACC synthase and two isogenes for ACC oxidase) and genes encoding cell wall modifying (two isogenes for polygalacturonase, two isogenes for cellulase and eight isogenes for expansin). The ripening ethylene production declined with decrease of transcripts for ACC synthase and ACC oxidase by 1-MCP, a strong inhibitor of ethylene action when it was applied to fruit after onset of climacteric ethylene. The results indicate that ripening ethylene biosynthesis in pear fruit is regulated in positive feedback manner. In addition of suppression of ethylene biosynthesis, 1-MCP application during ripening stage significantly delayed the subsequent fruit softening, resulting in extended shelf life more than twice of non-treated fruit. In the 1-MCP treated fruit the expression of three isogenes for expansin and two for polygalacturonase was suppressed while other members of expansin and two cellulase genes were not affected. These results suggest that expression of some expansin and polygalacturonase genes depends on ethylene and plays an important role in fruit softening. We concluded that application of 1-MCP and metabolic engineering of ethylene biosynthetic gene such as ACC synthase and ACC oxidase promise advanced postharvest technology in transportation and marketing in pear fruit.

为了建立质量更高的延长保质期后的延长保质期的生理基础，我们研究了分子水平上水果成熟和软化的机制。我们分离了乙烯生物合成基因（ACC合酶的四个ISEGENES和ACC氧化酶的两个ISEGENES）和编码细胞壁修饰的基因（两个用于多半乳甲促旋蛋白酶的ISEGENES，两个用于纤维素酶的ISEGENES，八个用于膨胀蛋白的ISOGENES）。成熟的乙烯产量下降，随着1-MCP的转录本的转录本下降，1-MCP是一种强烈的乙烯作用抑制剂，当它在高潮乙烯发作后将其应用于果实时。结果表明，梨果实中的乙烯生物合成以积极的反馈方式调节。除了抑制乙烯生物合成的抑制作用外，成熟阶段的1-MCP施用显着延迟了随后的果实软化，从而延长了延长的货架寿命，超过两次未处理的水果。在1-MCP处理的果实中，三种为膨胀蛋白的ISEGEN的表达和两个用于聚半乳糖苷酶的表达受到抑制，而膨胀蛋白和两个纤维素酶基因的其他成员则不受影响。这些结果表明，某些膨胀蛋白和多边形蛋白酶基因的表达取决于乙烯，并且在果实软化中起着重要作用。我们得出的结论是，乙烯生物合成基因的1-MCP和代谢工程的应用，例如ACC合酶和ACC氧化酶有望在梨果实中的运输和营销中进行先进的后验后技术。