紫茉莉内切β甘露聚糖酶对石油污染土壤应答机制的研究

发布时间：2018-06-15 20:43

本文选题：紫茉莉内切β甘露聚糖酶 + 生理　；参考：《沈阳农业大学》2017年硕士论文

【摘要】：石油污染是重要的环境污染问题之一,亟待解决。作为环境友好的花卉植物修复,因其美观且无二次污染而受到广泛关注,但植物对石油污染的耐受性是发挥其修复能力的先决条件。本研究在前人研究基础上,通过转录组数据分析获得了显著上调的紫茉莉内切β甘露聚糖酶基因,明确其对石油污染胁迫的表达响应,揭示紫茉莉耐受石油污染胁迫的分子机制。本研究对石油污染胁迫下该基因的半定量和实时荧光定量表达变化分析表明:在石油胁迫下,紫茉莉内切β甘露聚糖酶基因显著上调,在]2-36h该基因相对表达量呈升高趋势,36h相对于]2h显著增加(p=0.05水平,p=0.004)为极显著差异,在0.05水平,显著性为0.004,在36 h达到最大值时,5-10 g/kg石油胁迫下基因表达水平显著高于20-40g/kg(p=0.05水平,p=0.001),所以石油污染土壤中紫茉莉内切β甘露聚糖酶基因的最佳响应石油处理时间为36 h,浓度为5-10 g/kg,该基因对于高浓度的石油污染土壤响应早于低浓度石油污染土壤。生物信息学预测,该基因定位于植物防御相关的质外体细胞壁,其功能与细胞壁相关,基因枪转化洋葱表皮细胞亚细胞定位实验证实其表达定位于细胞质体外。为了进一步探究该基因对石油污染土壤的应答机制,对石油污染土壤中生长的紫茉莉设置两组处理,试验组浇灌该基因水解产物——甘露寡糖(0.4mg*mL-1),对照组浇灌自来水,测定了两组处理下根和叶抗逆相关的酶活和膜损伤指标,结果显示,①综合抗氧化酶活性及膜脂损伤指标,石油污染浓度为20 g/kg时根仍表现出一定的耐受性,叶则在小于10 g/kg的石油污染土壤中有一定的耐受性,根和叶在对石油污染土壤的耐受性中有一定的差异,根比叶有更强的耐受性;②甘露寡糖处理下12h紫茉莉根中POD酶活在30 g/kg时升高了 9.5倍,12 h紫茉莉叶中POD酶活在10 g/kg时升高了 2.57倍。SOD、CAT的酶活也有一定的升高,甘露寡糖会使植物的抗氧化酶活升高;③根中丙二醛在36h、20 g/kg时下降53%,变化幅度最大,在其他处理时间和石油污染条件下,丙二醛含量也有不同程度的降低,植物抗逆能力增强。紫茉莉抗氧化酶系统有效保护了石油污染胁迫下的紫茉莉植株,氧化酶及膜损伤指标的变化说明了紫茉莉的石油烃反应机制。结合显著性分析,寡糖处理下,抗氧化酶和紫茉莉内切β甘露聚糖酶酶活(edMAN酶活)及膜损伤指标整体相比于对照组均呈显著差异,所以该基因对石油污染土壤的应答机制主要有两个方面:1是该基因改变紫茉莉根的细胞壁结构,提高植株抗逆;2是该基因相关的甘露寡糖作为诱导物质,通过诱导抗逆,抗氧化酶活性提高,对于紫茉莉石油污染土壤抗逆性的提高确实有帮助。
[Abstract]:Oil pollution is one of the important environmental pollution problems, which is urgent to be solved. As an environmentally friendly flower plant restoration, it is widely concerned because of its beauty and no two pollution. But the tolerance of plants to oil pollution is a prerequisite for the restoration of its ability. Based on previous studies, the study has been obtained by the analysis of transcriptional data. In this study, the semi quantitative and real-time quantitative analysis of fluorescence quantitative expression of the gene was analyzed under oil stress. The relative expression of the gene was increased significantly in]2-36h, and the 36h relative to the]2h increased significantly (p=0.05 level, p=0.004) was significantly different. At the 0.05 level, the significant difference was 0.004. When the 36 h reached the maximum, the gene expression level under 5-10 g/kg oil stress was significantly higher than that of 20-40g/kg (p=0.05 level, p=0.001). The best response to the oil contaminated soil was 36 h, and the concentration was 5-10 g/kg. The response of the gene to the high concentration of oil contaminated soil was earlier than the low concentration of oil contaminated soil. Bioinformatics predicted that the gene was located in the wall of the plant defense related extracellular somatic cell, and its function and refinement were fine. In order to further explore the response mechanism of the gene to oil contaminated soil, two groups of treatments were set up in the oil contaminated soil, and the experimental group poured the gene hydrolysate - manna oligosaccharide (0.4mg*mL-). 1) the control group was irrigated with tap water and measured the enzyme activity and membrane damage indexes related to the resistance to the root and leaf of the two groups. The results showed that the root was still tolerable when the oil pollution concentration was 20 g/kg, and the leaf was tolerable in the oil contaminated soil that was less than 10 g/kg, and the root was tolerable in the oil contaminated soil, which was smaller than 10. There was a certain difference in the tolerance of the leaf to the oil contaminated soil, and the root specific leaf was more tolerant. (2) the POD enzyme activity in the 12h purple jasmine root increased by 9.5 times at 30 g/kg under the manna oligosaccharide treatment. The POD enzyme activity in the 12 h purple jasmine leaves increased by 2.57 times.SOD, the enzyme activity of CAT was also raised, and manna oligosaccharides would make plants The activity of antioxidant enzymes in the root was increased, and the malondialdehyde in the root was decreased by 53% at 36h, 20 g/kg, and the maximum was changed. Under the other treatment time and the oil pollution, the content of malondialdehyde was also reduced in varying degrees and the resistance of plants increased. The changes in the index of membrane damage indicate the mechanism of petroleum hydrocarbon reaction of mirabilis. Combined with the significant analysis, compared with the control group, there are significant differences in the antioxidant enzyme activity (edMAN enzyme activity) and the membrane damage index in the oligosaccharide treatment under the oligosaccharide treatment. Therefore, there are two main responses of the base to the oil contaminated soil. The 1 is that the gene changes the cell wall structure of the purple jasmine root and improves the resistance to the plant, and the 2 is the mannan oligosaccharide as the inducer, which is helpful to improve the resistance of the oil contaminated soil by inducing the resistance and the increase of the antioxidant enzyme activity.
【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】：X53;X74

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