Mechanism of fruit softening and its inhibition during distribution and storage in persimmon fruit

柿果实软化机理及其在流通贮藏过程中的抑制作用

• 批准号: 14560023
• 负责人: KUBO Yasutaka
• 金额: $ 2.24万
• 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: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14560023/
• 关键词: Fruit softening; Ethylene; Japanese persimmon; Water stress; 1-MCP; ACC synthase; Cell wall modifying enzyme; Gene expression; 防湿段ボール箱

Persimmon fruit undergoes intensive cell wall modification during fruit softening in its postharvest life. In order to investigate the mechanism of fruit softening, we employed a strong inhibitor of ethylene action, 1-MCP, and the technique of molecular biology. As the first step, we cloned cDNAs for ACC synthase, ACC oxidase, cellulase (Cel), polygalacturonase (PG) and for expansin, from persimmon fruit and characterized their expression.Ethylene production was induced within a few days of harvest in all fruit tissues tested, accompanied by temporally and spatially coordinated expression of all the DK-ACS and DK-ACO genes. In all tissues except the calyx, treatment of 1-MCP suppressed ethylene production and ethylene biosynthesis-related gene expression. In the calyx, however, DK-ACS2 exhibited increased mRNA accumulation accompanied by a large quantity of ethylene production, and 1-MCP treatment did not prevent the events. Furthermore, the alleviation of water stress by packaging the … More fruit with perforated polyethylene bag significantly delayed the onset of ethylene production and the expression of DK-ACS2 in the calyx. These results indicate that ethylene biosynthesis in persimmon fruit is initially induced in calyx and is modulated by water loss through transcriptional activation of DK-ACS2. The ethylene produced in the calyx subsequently diffuses to other fruit tissues and acts as a secondly signal that stimulates autocatalytic ethylene biosynthesis in these tissues, leading to intensive fruit softening.The accumulation of DK-Cel3, DK-PG1, and DK-Exp2 mRNAs was induced simultaneously with commencement of ethylene production and softening in harvested 'Hiratanenashi' persimmon fruit. The MCP pre-treatment delayed the accumulation of these mRNAs and fruit softening while propylene treatment resulted in the accumulation of these mRNAs within one day and a rapid fruit softening. On the other hand, mRNAs for DK-Cell, DK-Cel2, and DK-Exp1 had already accumulated in the fruit at harvest and decreased during shelf life. These results indicate that the ethylene dependent gene expression of DK-Cel3, DK-PG1, and DK-Exp2 might be closely involved in fruit softening of 'Hiratanenashi' persimmon.We investigated the potential for commercial use of 1-MCP to extend the shelf life of 'Tonewase' and 'Saijo' fruit, in combination with de-astringency treatment using high carbon dioxide. The non-1-MCP treated fruits softened within 5 days after harvest, resulting in unacceptable quality. The 1-MCP treatments at more than 100 nl 1^<-1> for 16 -48 h inhibited fruit softening for 12 days and 16 days after harvest at room temperature in 'Tonewase' and 'Saijo', respectively. A time lag of up to 12 h from harvest to the beginning of 1-MCP treatment did not damage the beneficial effects of 1-MCP. These results indicate that 1-MCP is a promising chemical to extend shelf life of Japanese persimmons. Less

柿子果实在采后软化过程中，细胞壁发生了剧烈的变化。为了研究水果软化的机理，我们采用了强乙烯作用抑制剂1-MCP和分子生物学技术。首先，我们从柿子中克隆了ACC合成酶、ACC氧化酶、纤维素酶、聚半乳糖醛酸酶和扩增蛋白的cdna，并对它们的表达进行了表征。所有测试的果实组织在收获后几天内都能诱导乙烯产生，并伴有所有DK-ACS和DK-ACO基因在时间和空间上的协调表达。在除花萼外的所有组织中，1-MCP处理均抑制乙烯产生和乙烯生物合成相关基因的表达。然而，在花萼中，DK-ACS2表现出mRNA积累增加，同时大量产生乙烯，而1-MCP处理并没有阻止这一事件。此外，用穿孔聚乙烯袋包装更多的果实以缓解水分胁迫，显著推迟了乙烯的产生和花萼中DK-ACS2的表达。这些结果表明，柿子果实的乙烯生物合成最初是在花萼中诱导的，并通过DK-ACS2的转录激活受到水分损失的调节。花萼中产生的乙烯随后扩散到果实的其他组织，并作为刺激这些组织中自催化乙烯生物合成的第二信号，导致果实强烈软化。在收获的平田柿果实中，DK-Cel3、DK-PG1和DK-Exp2 mrna的积累与乙烯生产和软化的开始同时被诱导。MCP预处理延迟了这些mrna的积累和果实软化，而丙烯处理导致这些mrna在一天内积累，果实迅速软化。另一方面，DK-Cell、DK-Cel2和DK-Exp1的mrna在收获时已经在果实中积累，并在保质期内减少。这些结果表明，乙烯依赖基因DK-Cel3、DK-PG1和DK-Exp2的表达可能与平仁柿果实软化密切相关。我们研究了1-MCP的商业应用潜力，以延长“Tonewase”和“Saijo”水果的保质期，并结合使用高二氧化碳的去涩味处理。未经1- mcp处理的水果在收获后5天内软化，导致质量不可接受。1- mcp浓度大于100 n1 ^<-1>处理16 ~ 48 h，分别抑制了‘Tonewase’和‘Saijo’果实在室温下收获后12天和16天的软化。从收获到开始处理1-MCP长达12小时的时间滞后并没有损害1-MCP的有益效果。这些结果表明，1-MCP是一种很有前途的延长柿子货架期的化学物质。少

项目成果

Nakano, R., Y.Kubo, A.Inaba et al.: "Ethylene biosynthesis in detached young persimmon fruit is initiated in calyx and modulated by water loss from the fruit"Plant Phsysiology. 131. 276-286 (2003)

Nakano, R.、Y.Kubo、A.Inaba 等人：“分离的年轻柿子果实中的乙烯生物合成是在花萼中启动的，并通过果实的水分损失进行调节”植物生理学。

Nakano, R., Y.Kubo, A.Inaba et al.: "Ethylene biosynthesis in detached young persimmon fruit is initiated in calyxAnd modulated by water loss from the fruit"Plant Physiology. 131. 276-286 (2003)

Nakano, R.、Y.Kubo、A.Inaba 等人：“分离的幼柿果实中的乙烯生物合成是在花萼中启动的，并受果实失水的调节”植物生理学。

Harima, S., Y.Kubo et al.: "Extending shelf-life of astringent persimmon (Diospyros kaki)"Postharvest Biology and Technology. 29. 318-323 (2003)

Harima, S., Y.Kubo 等人：“延长涩柿 (Diospyros kaki) 的保质期”采后生物学和技术。

Kubo, Y., R.Nakano, A.Inaba: "Cloning of genes encoding cell wall modifying enzymes and their expression in persimmon fruit"Acta Horticulturae. 601. 49-55 (2003)

Kubo，Y.，R.Nakano，A.Inaba：“编码细胞壁修饰酶的基因的克隆及其在柿子果实中的表达”园艺学报。

Harima, S., Y.Kubo et al.: "Extending shelf-life of astringent persimmon (Diospyros kaki Thunb.) fruit by1-MCP"Postharvest Biology and Technology. 29. 318-323 (2003)

Harima, S., Y.Kubo 等人：“通过 1-MCP 延长涩柿 (Diospyros kaki Thunb.) 果实的保质期”采后生物学和技术。