C3H-RNAi转基因杨木组织细胞形态特征及细胞壁木质素变化规律研究

发布时间：2018-06-05 04:14

本文选题：转基因杨木 + 组织细胞　；参考：《中国林业科学研究院》2017年硕士论文

【摘要】：通过木质素基因工程能够有效降低杨木细胞壁木质素含量,从而改善人工林杨树作为木质纤维材料的利用现状。细胞壁关键组分木质素含量的变化对转基因杨木组织细胞微观构造以及对细胞壁其它重要化学成分的影响则具有重要研究意义。因此本论文选取转C3H基因银腺杨84K(Populus alba×P.glandulosa cv`84k')和非转基因银腺杨84K为实验材料,利用光学显微镜和电子显微镜观测了两类杨木组织细胞形态特征和木纤维形态参数的差异;利用乙酰溴法、热解-气相色谱/质谱联用和傅里叶变换红外光谱法测定和分析了转基因杨木木质素含量和结构的变化;利用组织化学染色、激光共聚焦显微技术和共聚焦显微拉曼光谱技术观察了转基因杨木木质素和多糖物质在组织细胞壁层的微区分布及沉积规律,并针对以上研究结果在不同高度的变化规律进行总结分析。本论文主要研究结果如下:1.转基因杨木组织细胞形态特征(1)转基因杨木仍为典型散孔材的特性。导管、木射线和纤维等各类型组织细胞在髓心到树皮方向的分布规律均与对照组杨木一致。但是发现部分转基因杨木导管壁形态为波浪状,与对照组杨木椭圆状存在一定差异。(2)转基因杨木纤维壁厚值(2.17μm)较对照组杨木(2.42μm)下降了12.40%;转基因杨木纤维长度(0.551 mm)较对照组杨木的(0.526 mm)增加了4.75%。且两类杨木纤维壁厚值和长度均随杨木的木质化程度增加而增加。而转基因杨木纤维腔径值(11.95μm)、宽度(21.1μm)与对照组杨木纤维腔径值(11.65μm)、宽度值(22.5μm)均无显著差异,但纤维壁腔比较对照组杨木的降低。(3)转基因杨木导管壁(1.92μm)较对照组杨木(2.12μm)变薄,平均下降9.43%,且不同高度导管壁厚无明显差异。转基因杨木不同高度的导管腔径均值(32.21μm)与对照组杨木(32.04μm)无明显差异,但导管壁腔比较对照组杨木的降低。2.转基因杨木木质素含量及结构变化(1)转基因杨木细胞壁主要化学组分结构与对照组杨木的一致,但木质素含量(25.0%)较对照组杨木(29.3%)降低,且在不同高度均呈下降趋势,平均下调量为14.68%,同时综纤维素相对含量增加。(2)转基因杨木中G和S单体相对含量较对照组的下降而H单体含量增加,转基因杨木木质素G、S、H单体相对含量分别为30.85%、54.69%、12.13%,对照组杨木的分别为34.39%、59.42%和6.19%。两类杨木木质素G和S单体的组成结构无明显差异,但转基因杨木H单体组成结构增加。3.转基因杨木木质素及多糖物质微区分布(1)转基因杨木木质素G单体在导管壁上均匀分布,S单体则在纤维细胞壁上均匀分布。转基因杨木木质素在纤维细胞壁层及各微区的含量分布规律为细胞角隅(CC)浓度最大、其次是复合胞间层(CML)和次生壁(S2),在木质部径向的沉积规律则为靠近髓心处组织细胞壁层沉积量较中部位置大,且与对照组杨木分布规律一致。(2)转基因杨木纤维细胞壁上的多糖物质主要分布于S2和CML上,而在CC沉积量较少,分布规律与对照组的一致。转基因杨木在纤维细胞S2和CML的处多糖物质沉积量大于对照组杨木对应微区,表明转基因杨木木质素含量降低后多糖物质含量补偿性增加。
[Abstract]:The lignin content of poplar cell wall can be effectively reduced by lignin gene engineering, thus improving the utilization status of the poplar wood as a wood fiber material. The changes in the content of the key components of the cell wall have important research on the microstructure of the tissue cells of the transgenic poplar and its influence on the cell wall its important chemical components. In this paper, C3H gene 84K (Populus Alba x P.glandulosa cv`84k') and non transgenic silver adenine 84K were selected as experimental materials. The morphological characteristics of two types of poplar tissue and the difference of morphological parameters of wood fiber were observed by optical microscope and electron microscope, and acetyl bromide method, pyrolysis gas chromatography / mass spectrometry was used. The contents and changes of lignin content and structure of transgenic poplar wood were measured and analyzed by combined and Fu Liye transform infrared spectroscopy. The microdistribution and deposition rules of the transgenic Yang Mu lignin and polysaccharide in the tissue cell wall were observed by histochemical staining, laser confocal microscopy and confocal Raman microraman spectroscopy. The main research results in this paper are as follows: 1. the morphological characteristics of the tissue cell of transgenic poplar wood (1) the transgenic poplar wood is still the characteristic of the typical dispersing wood. The distribution of the tissue cells in the medullary heart to the bark of the vessel, wood rays and fiber are all compared with those of the control. But it was found that some transgenic poplar wood duct wall morphology was wavy, and there were some differences with the control group. (2) the wall thickness of the transgenic poplar fiber (2.17 m) decreased by 12.40% compared with the control group (2.42 mu m), and the length of the transgenic poplar fiber (0.551 mm) increased by 4.75%. and two than that of the control group (0.526 mm). The wall thickness and length of the poplar fiber increased with the increase of wood lignification, but the diameter of the wood fiber (11.95 u m), the width (21.1 mu m), and the value of the wood fiber cavity of the control group (11.65 mu m), and the width (22.5 m) were not significantly different, but the fiber wall cavity was lower than the control group. (3) the transgenic poplar catheter wall (1.92 mu). M) thinner than the control group (2.12 mu m), the average decrease was 9.43%, and there was no obvious difference in the thickness of the catheter wall at different heights. There was no significant difference between the mean of the catheter cavity diameter of the different height of the transgenic poplar (32.21 mu m) and the control group of poplar (32.04 mu m), but the catheter wall cavity was compared with the control group Yang Mu's decrease in.2. transgenic poplar lignin content and structure change (1). The main chemical composition of the gene poplar cell wall was the same as that of the control group, but the lignin content (25%) was lower than that of the control group (29.3%), and the average down-regulation was 14.68%, and the relative content of the fully mechanized cellulose increased. (2) the relative content of G and S monomers in transgenic poplar wood was lower than that of the control group, H The relative content of G, S and H monomers of transgenic poplar lignin was 30.85%, 54.69%, 12.13%, respectively, and there was no significant difference in the composition of G and S monomers of poplar lignin in the control group 34.39%, 59.42% and 6.19%. two, but the composition structure of the transgenic poplar H monomer increased the.3. transgenic poplar lignin and the polysaccharide microarea. The distribution (1) of the transgenic poplar lignin G monomer distributed evenly on the catheter wall, and the S monomer distributed evenly on the wall of the fibrous cell. The distribution of the content of the transgenic poplar lignin in the cell wall and the microregions was the largest in the cell corner (CC), followed by the composite intercellular layer (CML) and the secondary wall (S2), and the radial sedimentary rules in the xylem. The deposition of the cell wall layer near the medullary center was larger than the central position, and the distribution law of poplar wood was consistent with the control group. (2) the polysaccharides on the cell wall of the transgenic poplar fiber were mainly distributed on S2 and CML, but the amount of deposition in CC was less and the distribution law was the same as that of the control group. The amount of mass deposition was higher than that of the control group, indicating that the content of polysaccharides in transgenic poplar decreased with increasing lignin content.
【学位授予单位】：中国林业科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S792.11

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