蓝光抑制‘南果梨’果实成熟过程中乙烯合成的机理研究

发布时间：2018-04-30 22:18

  本文选题：蓝光 + 抑制　； 参考：《沈阳农业大学》2017年硕士论文

【摘要】：果实的成熟过程是决定其贮藏性的重要因素。研究果实的成熟及调控机理对于人工调控果实贮藏性有重要的理论及实践意义。秋子梨(Pyrus ussuriensis Maxim)是我国北方地区特有的梨资源,大部分秋子梨包括'南果梨'是呼吸跃变型果实,其成熟过程主要受乙烯调控。除此之外,光、温度等外界环境因素也可以调控果实的成熟过程。近年来许多研究证明了蓝光能够抑制呼吸跃变型果实成熟过程中的乙烯合成,从而影响果实的贮藏性,但其分子机制尚不清楚。本研究以'南果梨'果实为试材,研究了蓝光通过其信号途径中的转录因子PuHYH1抑制乙烯合成关键基因PuACS1的表达进而调控果实成熟过程中的乙烯合成的分子机制。主要结果如下:1.从梨基因组克隆了光信号转导途径中的重要转录因子HY5的同源基因PuHYH1以及乙烯信号转导途径的重要转录因子ERF和乙烯合成的关键基因ACS、ACO,通过对其表达模式分析发现,蓝光处理后PuHYH1的表达上调乙烯合成关键基因PuACS1的表达下调,PuEPF2表达上调。2.酵母单杂交、EMSA试验发现PuHYH1和PnERF2均能够结合PuACS1的启动子;通过GUS报告基因活性测定试验发现PuHYH1和PuERF2均可负调控PuACS1基因的表达。3.通过酵母双杂交试验、Pull-down试验发现了 PuHYH1与PuERF2之间存在蛋白互作关系。4.通过GUS报告基因活性测定试验明确了 PuHYH1与PuERF2蛋白之间的互作可以增强PuERF2对PuACS1的负调控作用。以上结果表明:PuHYH1、PuERF2可以直接负调控PuACS1的表达,PuHYH1与PuERF2互作可以增强PuERF2对PuACS1的负调控,蓝光可能通过以上两条途径抑制PuACS1的表达进而抑制乙烯合成。本实验结果从分子水平阐明了蓝光抑制'南果梨'乙烯合成的机制,对如何提高'南果梨'的贮藏性研究提供了重要的理论基础。
[Abstract]:The ripening process of fruit is an important factor to determine its storage property. The study of fruit maturation and regulation mechanism has important theoretical and practical significance for artificial regulation of fruit storage. Pyrus ussuriensis Maximis is a unique pear resource in northern China. Most of the autumn pears, including 'Nanguo pear', are respiratory jump type fruits, and their ripening process is mainly regulated by ethylene. In addition, light, temperature and other external environmental factors can also regulate the fruit ripening process. In recent years, many studies have proved that blue light can inhibit ethylene synthesis in the ripening process of respiratory jump fruits, thus affecting the storage ability of fruits, but its molecular mechanism is not clear. In this study, the molecular mechanism of blue light inhibiting the expression of ethylene synthesis key gene PuACS1 and regulating ethylene synthesis during fruit ripening was studied using the fruit of 'Nanguo pear' as the experimental material, and the transcription factor PuHYH1 in its signaling pathway was used to inhibit the expression of the key gene of ethylene synthesis. The main results are as follows: 1. The homologous gene PuHYH1 of important transcription factor HY5 in light signal transduction pathway, the important transcription factor ERF of ethylene signal transduction pathway and the key gene of ethylene biosynthesis, ACSACO, were cloned from the genome of pear. The expression of PuHYH1 upregulated after blue light treatment down-regulated the expression of PuACS1, the key gene of ethylene synthesis, and upregulated the expression of PuEPF2. The results showed that both PuHYH1 and PnERF2 could bind to the promoter of PuACS1, and PuHYH1 and PuERF2 could negatively regulate the expression of PuACS1 gene by GUS reporter gene activity assay. The protein interaction between PuHYH1 and PuERF2 was found by the pull-down test of yeast two-hybrid. 4. GUS reporter gene activity assay showed that the interaction between PuHYH1 and PuERF2 protein could enhance the negative regulation of PuERF2 on PuACS1. These results suggest that the interaction of PuHYH1 and PuERF2 can directly and negatively regulate the expression of PuACS1. The interaction between PuHYH1 and PuERF2 can enhance the negative regulation of PuACS1 by PuERF2. Blue light may inhibit the expression of PuACS1 and inhibit ethylene synthesis through these two pathways. In this study, the mechanism of blue light inhibiting ethylene synthesis of 'Nanguo pear' was elucidated at molecular level, which provided an important theoretical basis for the study on how to improve the storage ability of 'Nanguo pear'.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S661.2
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本文编号：1826477