茉莉酸甲酯对颠茄主要生物碱含量的影响及其机理

发布时间：2018-04-28 02:20

本文选题：颠茄 + 茉莉酸甲酯　；参考：《西南大学》2017年硕士论文

【摘要】：颠茄(Atropa belladonna L.)是茄科颠茄属的重要药用植物,主要次生代谢产物莨菪碱与东莨菪碱作为重要的抗胆碱类药物广泛应用,但由于在药用植物中的含量低,其产量远远低于市场需求。而用外源添加物处理植物是常用且有效的方法,茉莉酸甲酯(MeJA)作为一种对植物生长具有广泛调节作用的物质,已研究发现能够提高多种药用植物中的次生代谢物含量。本试验以颠茄为材料,设置了不同浓度的MeJA处理组,0μmol·L-1、100μmol·L-1、200μmol·L-1、300μmol·L-1、400μmol·L-1,研究不同浓度MeJA对颠茄植株生长、生理特性、叶片中主要生物碱含量的影响,并从氮代谢、托品烷类生物碱(TAs)生物合成途径中的关键中间产物以及关键酶基因表达量等方面,展开对MeJA调控颠茄TAs的作用机理研究。主要研究结论如下:1.比较不同浓度MeJA处理对颠茄生理特性的影响,结果表明:MeJA处理后颠茄叶片中叶绿素a与叶绿素b含量均显著降低,说明MeJA能够促进颠茄叶绿素降解或抑制叶绿素的合成。较低浓度的MeJA(100μmol·L-1、200μmol·L-1)处理在整个处理期都能显著提高颠茄叶片中脯氨酸含量,较高浓度MeJA(300μmol·L-1、400μmol·L-1)随处理时间的延长呈先升高后降低或平衡的趋势,说明MeJA可以提高颠茄叶片脯氨酸含量,降低其渗透势,保持水压,减少对细胞的伤害。MeJA处理显著提高了颠茄叶片中可溶性蛋白含量,可能是MeJA刺激了颠茄叶片中防御蛋白的合成,防御系统启动时各种催化酶类大量合成,从而影响颠茄的生理生长代谢等。2.研究MeJA对颠茄生长与主要生物碱含量的影响发现:MeJA处理能够抑制颠茄的生长,且随处理时间的延长抑制作用越明显。颠茄叶片中莨菪碱与东莨菪碱含量在MeJA处理后变化趋势基本一致,100μmol·L-1MeJA要处理14 d后才能显著提高主要生物碱含量,而200μmol·L-1、300μmol·L-1、400μmol·L-1 MeJA处理7 d就能显著提高颠茄叶片两种生物碱的含量。其中200μmol·L-1在处理28 d时,莨菪碱与东莨菪碱含量达到最大值,分别为对照的1.706倍与1.807倍。总体来看,茉莉酸甲酯能促进颠茄莨菪碱、东莨菪碱的合成。3.为阐明MeJA调控颠茄叶片中莨菪碱与东莨菪碱的机理,对处理28 d时颠茄叶片中NO、氮代谢关键酶、TAs生物合成途径精氨酸脱羧酶(ADC)与鸟氨酸脱羧酶(ODC)、多胺含量以及叶片和根中关键酶基因表达量进行研究。研究发现:MeJA可刺激颠茄叶片中NO的迸发,但变化趋势不同于主要生物碱含量。MeJA处理可以降低硝态氮含量,随处理浓度升高,硝酸还原酶(NR)与谷氨酰胺合成酶(GS)活性变化趋势一致,NR活性得到提高,GS活性除400μmol·L-1处理也得到提高,总体来看MeJA提高了氮代谢水平。MeJA还可提高ADC活性以及200μmol·L-1、300μmol·L-1处理时ODC的活性。腐胺含量在MeJA处理后显著提高,而精胺与亚精胺变化较小。但主要生物碱含量与腐胺的含量变化不完全一致,可能还与TAs合成途径下游关键酶有关。除100μmol·L-1处理外,MeJA对颠茄根中pmt的表达无显著影响。但促进了叶中trⅠ以及根中trⅠ和h6h的表达,根中trⅠ表达量的变化趋势与莨菪碱和东莨菪碱含量的变化基本一致,能够促进代谢向合成莨菪碱和东莨菪碱的方向移动,h6h可促进莨菪碱生成东莨菪碱。综上,推测MeJA对颠茄托品烷类生物碱含量影响的机理,主要是通过促进颠茄根中trⅠ和h6h基因的表达,促进次生代谢向合成莨菪碱和东莨菪碱的方向进行。此外,适宜浓度的MeJA还可提高颠茄叶片中氮代谢水平,提高ADC、ODC酶活性以及腐胺含量,从而为下游TAs的合成提供充足的前体物质。
[Abstract]:Atropa belladonna L. (belladonna) is an important medicinal plant of the Solanaceae. The main secondary metabolites, scopolamine and scopolamine, are widely used as important anticholinergic drugs. However, the yield is far below the market demand because of the low content of the medicinal plants, and the treatment of plants with external additives is a common and effective method. Methyl jasmonate (MeJA), as a substance which has a wide regulating effect on plant growth, has been found to be able to increase the secondary metabolite content in a variety of medicinal plants. This experiment uses belladonna to set up different concentrations of MeJA treatment group, 0 u mol. L-1100, L-1200, L-1300, L-1300, L-1300, L-1400, mol. The effects of MeJA on the growth and physiological characteristics of belladonna, the main alkaloid content in the leaves and the key intermediate products in the biosynthesis pathway of the TAs biosynthesis pathway and the gene expression of the key enzymes were studied. The main conclusions were as follows: 1. the main conclusions are as follows: 1. The effects of the same concentration of MeJA on the physiological characteristics of belladonna showed that the content of chlorophyll a and chlorophyll b in the leaves of belladonna decreased significantly after MeJA treatment, indicating that MeJA could promote the degradation of belladonna chlorophyll or inhibit the synthesis of chlorophyll. The lower concentration MeJA (100 mu mol. L-1200, mol L-1) can be significantly improved in the whole treatment period. Proline content in belladonna leaves, high concentration of MeJA (300 mu mol. L-1400 Mu mol. L-1) increased first and then decreased or balanced with the prolongation of treatment time, indicating that MeJA could improve the proline content of belladonna leaves, decrease its osmotic potential, maintain water pressure, and reduce the damage to cells by.MeJA treatment, which significantly improved the soluble eggs in belladonna leaves. The white content may be that MeJA stimulates the synthesis of defensive proteins in the belladonna leaves, and a large number of catalytic enzymes are synthesized at the start of the defense system, which affects the physiological growth and metabolism of the belladonna and other.2. studies on the effects of MeJA on the growth of Belladonna and the main alkaloid content. It is found that MeJA treatment can inhibit the growth of Belladonna and inhibit the growth of belladonna. The more obvious the production is. The changes in the contents of scopolamine and scopolamine in the vane of belladonna are basically the same after MeJA treatment. The content of the main alkaloids can be significantly increased after 100 mu mol. L-1MeJA is treated with 14 d. The content of two alkaloids of the high belladonna leaves can be significantly raised by 7 d. 20, mol. L-1400, mol L-1 MeJA. 0 Mu mol. L-1 reached the maximum value of scopolamine and scopolamine at the maximum value of 28 d, 1.706 times and 1.807 times the control, respectively. In general, methyl jasmonate could promote Belladonna and scopolamine synthesis.3. to clarify the mechanism of MeJA regulation of belladonna scopolamine and scopolamine, NO, nitrogen generation in belladonna leaves at 28 d treatment. Key enzyme, TAs biosynthesis pathway, arginine decarboxylase (ADC) and ornithine decarboxylase (ODC), polyamine content and gene expression of key enzymes in leaves and roots. The study found that MeJA can stimulate the burst of NO in belladonna leaves, but the change trend is different from the main alkaloid content.MeJA treatment can reduce nitrate nitrogen content everywhere. As the concentration increased, the activity of nitrate reductase (NR) and glutamine synthetase (GS) was the same, the activity of NR was improved and the activity of GS was improved in addition to 400 mu mol. L-1. In general, the MeJA increased the nitrogen metabolism level and the activity of ADC activity, as well as the activity of 200 mu mol. The changes of spermine and spermine were smaller, but the content of the main alkaloids was not exactly consistent with the changes in the content of the putrescine. It may also be related to the key enzymes in the downstream of TAs synthesis. Except for the treatment of 100 mu mol. L-1, MeJA has no significant influence on the expression of PMT in the belladonna root, but it promotes the expression of TR I and h6h in the leaves of TR I and the roots. The change in the expression of TR I was basically consistent with the changes in the content of scopolamine and scopolamine, which could promote the direction of metabolism to the direction of scopolamine and scopolamine. H6h could promote the formation of scopolamine. The mechanism of the effect of MeJA on the content of alkanoid alkaloids in belladonna, mainly by promoting the TR in belladonna root. The expression of I and h6h gene promotes the direction of secondary metabolism to synthesis of scopolamine and scopolamine. In addition, the suitable concentration of MeJA can also improve the level of nitrogen metabolism in the vane of belladonna, improve the activity of ADC, ODC enzyme and the content of the putrescine, thus providing sufficient precursors for the synthesis of TAs in the lower reaches.

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q946

【参考文献】