采前Stroby和BTH喷洒对厚皮甜瓜果实发育期细胞壁强化及采后软化的抑制

发布时间：2018-03-03 11:28

本文选题：厚皮甜瓜　切入点：采前喷洒　出处：《甘肃农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：厚皮甜瓜属典型跃变型果实,果实采后代谢旺盛,易发生软化变质。本文以“玛瑙”厚皮甜瓜为试材,采用400mg/L Stroby、100mg/L苯丙噻重氮(BTH)以及1mM水杨羟肟酸(SHAM)分别在甜瓜果实幼果期(花后2周)、膨大前期(花后3周)、膨大后期(花后4周)及采前48h四个时期连续喷施4次,分析果实发育期间细胞壁代谢关键酶及组分的变化,测定采收及冷藏期间失重率、硬度、细胞壁组分、细胞壁降解酶活性及相关基因的表达,从生理生化和分子水平探讨Stroby、BTH和SHAM处理对果实发育期间细胞壁强化及采后软化的影响。结果表明:1.Stroby和BTH处理提高了果实发育期间细胞壁代谢酶蔗糖合成酶(SuSy)活性,促进了CmSuSy和CmCASE基因表达,增加了果实CDTA可溶性果胶(CSP)、碳酸钠可溶性果胶(DASP)、纤维素、半纤维素、富含羟脯氨酸蛋白(HRGPs)和木质素含量,促进了细胞壁物质的合成。2.Stroby和BTH处理降低了果实的采后失重率,维持了果实采收及冷藏期间的硬度,延缓了冷藏期间原果胶向水溶性果胶(WSP)的转化,维持了较高的CSP、DASP、纤维素、半纤维素、HRGPs和木质素水平,抑制了果实的采后软化。3.Stroby和BTH处理抑制了果胶甲酯酶(PME)、多聚半乳糖醛酸酶(PG)、纤维素酶(Cx)和β-葡萄糖苷酶(β-Glu)的活性,降低了CmPME、CmPG和CmCx的表达,阻止了细胞壁物质的释放,进而有效维持冷藏期间甜瓜果实硬度。4.Stroby和BTH处理诱导了果实POD活性及基因表达,提高了POD同工酶谱带活性。Stroby和BTH处理增加了H2O2含量,促进了H2O2在细胞壁中累积。此外,POD抑制剂SHAM抑制了Stroby和BTH诱导的H2O2积累,降低了POD活性及基因表达,弱化了细胞壁交联。综上所述,果实发育期间Stroby和BTH多次喷洒可提高厚皮甜瓜细胞壁代谢相关酶活性及相对基因的表达,促进细胞壁物质的合成,提高果实的细胞壁强度。此外,采前Stroby和BTH处理还可降低细胞壁降解酶活性及相对基因的表达,阻止了细胞壁物质的释放,维持了采收及冷藏期间的硬度,抑制了厚皮甜瓜果实的采后软化。
[Abstract]:Muskmelon is a typical type of fruit with high metabolism after harvest and easy to soften and deteriorate. In this paper, "agate" muskmelon was used as the test material. 400 mg / L Strobyn 100 mg / L benzothiazepine (BTH) and 1 mm salicyloxime acid (SHAM) were sprayed continuously at four stages of muskmelon fruit (2 weeks after anthesis, 3 weeks after anthesis, 4 weeks after anthesis) and 48 h before harvest, respectively. The changes of key enzymes and components of cell wall metabolism during fruit development were analyzed. The weight loss rate, hardness, cell wall components, cell wall degradation enzyme activity and the expression of related genes were determined during harvest and cold storage. The effects of SHAM and SHAM treatment on cell wall enhancement and postharvest softening during fruit development were studied at physiological, biochemical and molecular levels. The results showed that 1. Stroby and BTH treatments increased the activity of sucrose synthase during fruit development. It promoted the expression of CmSuSy and CmCASE genes, and increased the contents of CDTA soluble pectin, sodium carbonate soluble pectin, cellulose, hemicellulose, hydroxyproline rich protein and lignin. Stroby and BTH treatments decreased the weight loss rate of fruit, maintained the hardness of fruit during harvest and cold storage, delayed the transformation of original pectin to water-soluble pectin during cold storage, and maintained a high level of CSP DASP, cellulose. HRGPs and lignin levels of hemicellulose inhibited postharvest softening. 3. Stroby and BTH treatments inhibited the activities of PMEM, PGN, CXand 尾 -Glusidase (尾 -Gluidase), and decreased the expression of CmPMECmPG and CmCx. The cell wall material release was prevented, and the fruit firmness. 4. Stroby and BTH treatments induced the activity of POD and gene expression, and increased the activity of POD isozyme band. Stroby and BTH treatment increased the content of H2O2. In addition, SHAM inhibited H _ 2O _ 2 accumulation induced by Stroby and BTH, decreased POD activity and gene expression, and weakened cell wall cross-linking. Multiple spraying of Stroby and BTH during fruit development can increase the activity of enzymes related to cell wall metabolism and the expression of relative genes in muskmelon, promote the synthesis of cell wall substances and enhance the cell wall strength of fruit. Pretreatment with Stroby and BTH also decreased cell wall degradation enzyme activity and relative gene expression, prevented cell wall material release, maintained hardness during harvest and cold storage, and inhibited postharvest softening of thick muskmelon fruit.
【学位授予单位】：甘肃农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S652;TS255.3

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