| 摘要: |
| 【目的】探究制干枣品种骏枣果实在成熟过程中细胞壁物质和相关酶类的动态变化规律，以及相关基因的表达调控机制，为枣果实发育与成熟评价提供依据。【方法】选取制干枣骏枣白熟期至完熟期7个时期的果实样品，测定硬度、含水量、可溶性固形物（TSS）含量、色差、果胶和纤维素含量及多聚半乳糖醛酸酶（PG）、果胶酯酶（PE）、纤维素酶（Cx）活性；根据枣果实转录组测序的基因注释选择15个细胞壁代谢相关基因，用实时荧光定量PCR验证其在各个时期的表达量，并分析骏枣生理指标与基因表达量的相关性。【结果】（1）随着骏枣果实的成熟，其硬度在完熟后期显著降低，果实含水量呈下降趋势，TSS含量线性上升，色差指标在完熟期趋于稳定。（2）果胶和纤维素含量前期无显著变化，但完熟期有所增加，PG活性呈波动状态，PE和Cx活性有所增加。（3）3个PG相关基因表达量在完熟期降至较低水平，3个PE相关基因表达量在脆熟期达到峰值，纤维素及其酶类7个相关基因的表达量在各个时期表现不同，其中β-Glu40在完熟期表达量比其他基因高。【结论】PG及其相关基因与骏枣果实成熟和软化的相关性小，PE相关基因对果实软化具有先导作用，Cx及其相关基因对果实成熟具有联合调控作用。 |
| 关键词: 枣 果实成熟 软化 细胞壁 基因表达 |
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| 基金项目:国家“十二·五”科技支撑课题（2013BAD14B03-03）；陕西省科技统筹课题（2013KTZB03-03-01） |
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| Metabolism of pectin and cellulose and expression of related genes of ‘Junzao’ jujube fruit during ripening |
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LI Huan,ZHANG Shuyi,ZHANG Zhong,et al
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| Abstract: |
| 【Objective】This study explored the dynamic changes of cell wall materials and related enzymes as well as the regulation mechanism of related genes in dry jujube ‘Junzao’ (Ziziphus jujuba Mill.) during fruit ripening and softening to provide basis for jujube fruit development and maturing evaluation.【Method】The fruits of dry jujube ‘Junzao’ at seven developmental stages (from white mature to ripe stage) were chosen to determine the firmness, water content,total soluble solid (TSS),color parameters,contents of pectin and cellulose,and activities of polygalacturonases,pectinesterases and Cx-cellulase.Then,15 genes involving in cell wall metabolism of ‘Junzao’ fruit were selected,and their relative expression levels at different stages were determined by qRT PCR for function conformation.The correlations between physiological indices and gene expression in ‘Junzao’ fruit were also analyzed.【Result】(1) During the fruit ripening process,the firmness decreased significantly at late ripe stage,water content decreased,TSS content increased linearly,and color parameters tended to be stable at ripe stage.(2) The pectin and cellulose contents did not change significantly at very early stages but increased during ripe stages.PG activity was undulated,while the activities of PE and Cx-cellulase increased slightly.(3) The expressions of three PG genes decreased to very low levels.The expression levels of three PE genes reached peaks at crispy mature stages.The expressions of seven genes involving in cellulose and Cx-cellulase were different,in which β-Glu40 had higher levels than other genes at ripe stage.【Conclusion】The correlations between PG as well as PG genes and fruit ripening were weak.PE genes played a leading role in fruit softening and the genes involving in cellulose and Cx-cellulase together regulated fruit ripening. |
| Key words: Ziziphus jujuba Mill. ripening softening cell wall gene expression |
