番茄中油菜素内酯缓解氧化锌纳米颗粒胁迫及褪黑素在硒诱导镉胁迫抗性中的作用机理研究

发布时间：2018-04-04 15:42

本文选题：油菜素内酯　切入点：氧化锌纳米颗粒　出处：《浙江大学》2016年博士论文

【摘要】：由于人类活动和工业迅猛发展的影响,土壤重金属污染状况日益严重。这不仅影响了我国农业的可持续发展,也会直接影响农产品质量安全。此外,随着工业化水平的提高,越来越多新型的金属纳米颗粒进入环境当中,它们除了自身的金属特性外,还具有许多特有的物理化学特性,对环境和人类的带来了新的威胁。植物在长期进化的过程中形成了一套复杂的对抗重金属胁迫的机制。植物可以通过调控体内激素平衡和物质代谢缓解重金属毒害作用。因此,剖析植物激素和物质代谢对重金属及金属纳米颗粒胁迫抗性的调控机制,运用激素和有益物质物质处理等手段增强蔬菜作物对重金属及金属纳米颗粒胁迫的抗性,提高蔬菜产量、品质和经济效益,以及建立可持续农业皆具有十分重要的科学和现实意义。本文以番茄(SolanumlycopersicumL.)为植物材料,研究了油菜素内酯(BR)在缓解氧化锌纳米颗粒(ZnO NPs)毒害中的作用;通过处理不同形态硒(Se)元素,研究了 Se对番茄生长和抗氧化能力的影响。最后,利用病毒诱导的基因沉默技术(VIGS)研究了褪黑素在Se介导的番茄Cd胁迫抗性中的作用机制。所取得的主要研究结果如下:1.研究BR在缓解ZnO对番茄毒害中的作用。随着ZnONPs浓度(10～100 mg/L)的增加,幼苗体内Zn含量逐渐增加,幼苗的生长、生物量和根系活力逐渐下降。5 nMBR显著缓解了 50 mg/L ZnO NPs引起的生长抑制。通过染色和定量的方法发现,ZnO NPs大量增加了幼苗H202的积累,并造成幼苗膜脂过氧化,引起了氧化胁迫。BR处理之后明显缓解了 ZnO NPs的氧化胁迫。与单独ZnO NPs处理相比,BR添加之后进一步加强了抗氧化物酶SOD、APX、CAT和GR的活性,提高了还原型谷胱甘肽(GSH)的含量及GSH:GSSG的比例。与之对应,在ZnO NPs胁迫下,BR显著提高了抗氧化相关基因Cu/Zn SOD,CAT1,GSH1和GR1的表达。此外,BR还显著减少了 ZnO NPs胁迫下番茄幼苗体内Zn积累。这些结果充分表明,BR可以有效缓解ZnONPs对番茄幼苗的毒害。2.研究不同形态Se对番茄生长和抗氧化能力的影响。3μM不同形态Se化合物硒代半胱氨酸(Se-Cys)、Na2Se03和Na2Se04处理均提高了番茄的光合速率,促进了番茄植株的生长和生物量的积累,而对照的含硫化合物3μM半胱氨酸(Cys)、Na2S03和Na2SO4对番茄生长的影响并不明显。番茄根系对不同形态Se的吸收差异不大,但与Se-Cys和Na2SeO4处理相比,番茄对Na2SeO3的吸收效率较低,Na2SeO3处理后番茄叶片中的Se含量显著低于Se-Cys和Na2SeO4处理。不同类型Se处理通过提高GPX的活性、GSH的含量以及GSH:GSSG的比例提高了番茄植株的总抗氧化能力,其中Se-Cys的作用最为显著。不同类型Se处理显著提高了褪黑素合成基因的表达和番茄内源褪黑素以及其前体物质色胺和5羟色胺的含量。这些结果充分表明,不同形态Se处理促进了番茄植株的生长,提高了植物的抗氧化能力,并且Se-Cys处理效果最优,Na2SeO3处理效果最弱。3.研究褪黑素在Se介导的番茄镉(Cd)胁迫抗性中的作用机理。Se-Cys、Na2SeO3和Na2SeO4三种不同形态的Se都缓解了番茄Cd胁迫,其中Se-Cys对缓解番茄Cd毒害效果最好。此外,外源添加Se-Cys和褪黑素通过提高内源褪黑素水平显著增强了番茄植株Cd抗性,缓解了 Cd胁迫引起的生长抑制,光抑制和电解质溢出。然而,色氨酸脱羧酶基因(TDC)沉默抑制了 Se介导的番茄植株Cd抗性。Se-Cys处理提高了对照植株体内谷胱甘肽(GSH)和植物螯合肽(PCs)的含量以及GSH和PCs合成基因GSH1和PCS的表达,但是Se-Cys的作用在TDC沉默植株中被抑制。我们的结果表明褪黑素通过调控Cd的解毒,参与了Se介导的番茄Cd胁迫抗性。
[Abstract]:Due to the influence of human activities and the rapid development of industry, the status of soil heavy metal pollution is increasingly serious. This not only affects the sustainable development of agriculture in our country, will directly affect the quality and safety of agricultural products. In addition, with the progress of industrialization, more and more new metal nano particles into the environment, in addition to their own characteristics of the outer metal also, has many unique physical and chemical properties of the environment and human beings brought new threats. The plant has formed a complex mechanism against heavy metal stress during the long-term evolution. Plants can alleviate heavy metal toxicity by regulating hormone balance and metabolism. Therefore, the analysis of plant hormones and regulation mechanism metabolism on stress resistance of heavy metals and metal nanoparticles, use of hormone and beneficial substances enhanced treatment of heavy metal in vegetable crops The resistance of metal nanoparticles and stress, improve vegetable yield, quality and economic benefits, has very important scientific and practical significance as well as the establishment of sustainable agriculture. In this paper, tomato (SolanumlycopersicumL.) as plant material, the effect of Brassinolide (BR) in relief Zinc Oxide (ZnO NPs) nanoparticles toxicity effect; through the treatment of different forms of selenium (Se) elements, the effects of Se on growth and antioxidant capacity of tomato. Finally, using virus induced gene silencing (VIGS) on the mechanism of resistance of melatonin in Se mediated tomato Cd stress. The main results are as follows: 1. the study of BR in remission effect of ZnO on Tomato toxicity in. As the concentration of ZnONPs (10~100 mg/L) increased the Zn content of seedlings increased, seedling growth, biomass and root activity decreased,.5 nMBR significantly relieved 50 m G/L ZnO growth inhibition by NPs. Through the method of staining and quantitative ZnO NPs found a large increase in the accumulation of H202 and seedling, seedlings caused by membrane lipid peroxidation, causing oxidative stress after.BR treatment significantly alleviated the oxidative stress of ZnO NPs. Compared with ZnO alone NPs, BR added after the further strengthening of the antioxidant enzyme SOD, APX, CAT and GR activity, increased glutathione (GSH) content and GSH:GSSG ratio. In contrast, in ZnO under the stress of NPs, BR significantly increased the antioxidant related gene Cu/Zn, SOD, CAT1, expression of GSH1 and GR1. In addition, BR also significantly reduced ZnO NPs under the stress of Zn accumulation in tomato seedlings. These results indicate that BR can effectively alleviate the toxicity of.2. ZnONPs on Tomato Seedling of different forms of Se effect on the growth and antioxidant capacity of tomato.3 M of different forms of selenocysteine (Se compounds Se-Cys, Na2Se03 and Na2Se04) treatment increased the tomato photosynthetic rate, promote the growth and biomass accumulation of tomato plants, and sulfur compounds control 3 M cysteine (Cys), Na2S03 and Na2SO4 on the growth of tomato was not obvious. The absorption difference in tomato roots of different forms of Se, but compared with Se-Cys and Na2SeO4, the absorption efficiency of tomato Na2SeO3 is lower, the content of Se in tomato leaves after Na2SeO3 treatment was significantly lower than that of Se-Cys and Na2SeO4. The different types of the activity of GPX increased by Se treatment, the content of GSH and GSH: GSSG to increase the proportion of the total antioxidant capacity of tomato plants, the effect of Se-Cys is the most significant. Different types of Se significantly increased the gene expression and synthesis of melatonin and melatonin content of the tomato endogenous precursors tryptamine and 5 HT. These results indicate that the different shape Se treatment promoted tomato growth, improve the plant antioxidant capacity, and Se-Cys was the most effective, the treatment effect of Na2SeO3.3. on the weakest of melatonin in tomato cadmium mediated by Se (Cd) stress mechanism of.Se-Cys resistance, Na2SeO3 and Na2SeO4 with three different forms of Se are alleviated Cd stress in tomato among them, Se-Cys to alleviate Cd toxicity effect of tomato is best. In addition, exogenous Se-Cys and endogenous melatonin melatonin levels significantly enhanced by improving tomato Cd resistance, alleviate Cd stress caused growth inhibition, photoinhibition and electrolyte overflow. However, Tryptophan Decarboxylase (TDC) gene silencing mediated by Se in tomato plant resistance to Cd.Se-Cys increased the control of plant glutathione (GSH) and phytochelatins (PCs) content and the expression of GSH and PCs synthesis genes GSH1 and PCS, but the role of Se-Cys in TD The C silencing plants were suppressed. Our results showed that melatonin was involved in the Se mediated resistance to tomato Cd stress by regulating the detoxification of Cd.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S641.2

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