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新疆北部主要盐生植物内生细菌多样性研究
文献类型：学位论文
| 作者 | 赵帅 |
| 学位类别 | 博士 |
| 答辩日期 | 2015 |
| 授予单位 | 中国科学院大学 |
| 授予地点 | 北京 |
| 导师 | 田长彦 |
| 关键词 | 盐生植物 内生细菌 微生物多样性 微生物生态 |
| 学位专业 | 理学博士 |
| 中文摘要 | 盐生植物是修复盐渍土的有效工具，开发利用盐生植物内生细菌具有增强植物修复效果的潜力。然而，人们对盐生植物内生细菌多样性知之甚少。因此，本研究首次以生长在同一盐渍生境中不同种盐生植物和不同盐渍生境中同一种盐生植物为研究对象，采用454高通量测序技术和传统的分离培养方法结合分析内生细菌群落多样性、时空分布规律和生物学功能，并对潜在的内生细菌新种进行鉴定。其主要结果如下：（1）454高通量测序结果表明北疆地区盐生植物体内存在多样的内生细菌。16种盐生植物内生细菌主要由Proteobacteria、Tenericutes、Actinobacteria 和Firmicutes四个门的细菌组成。这四个门的细菌又分别以Gammaproteobacteria纲，Mollicutes纲，Actinobacteria纲，Bacilli纲为主。（2）同一盐渍生境中，盐生植物种类影响内生细菌群落结构。从植物种水平来看，不同种盐生植物内生细菌群落存在差异，刚毛柽柳、多枝柽柳、琵琶柴三种植物内生细菌多样性明显小于其它植物；从植物属水平来看，同一属的不同种盐生植物内生细菌相似；从植物科水平来看，藜科盐生植物内生细菌以Actinobacteria，Proteobacteria门为主；蒺藜科盐生植物内生细菌以 Proteobacteria门为主；柽柳科盐生植物内生细菌以Tenericutes门为主；白花丹科盐生植物内生细菌以Proteobacteria，Fimicutes，Actinobacteria门为主。（3）盐生植物内生细菌群落分布具有时空性，盐生植物发育期和盐渍环境共同影响内生细菌群落结构。具体表现为内生细菌群落结构随着宿主发育阶段发生改变，但在两个盐渍生境呈现不同变化规律，生长在阜康的盐角草不同发育时期内生细菌群落主要菌属均为Pseudomonas，而生长在克拉玛依的盐角草不同发育时期内生细菌群落主要菌属在不断改变，分别为Pseudomonas和Delftia，Kushneria，Serratia和Pantoea，Pantoea，Erwinia。（4）盐生植物体内存在具有促进植物生长潜力的内生细菌，接种具有促生能力的内生细菌可促进盐生植物种子萌发与生长，提高其抗盐能力。以分离培养方法从14种盐生植物分离出186株内生细菌，分布于4个门，103个种。其中2株细菌具有固氮活性；57株具有溶磷能力；25株具有产铁载体能力；13株具有产IAA能力；9株具有ACC脱氨酶活性；16株可以产蛋白酶；2株产脂肪酶；53株产纤维素酶。耐盐性测定显示这些菌株普遍可以耐受NaCl。菌株Variovorax paradoxus XJB-YJ2，Bacillus endophyticus XJB-YJ4，Arthrobacter agilis XJB-YJ21，Bacillus tequilensis YJ-S4 和 Planococcus rifietoensis YJ-ST4分离自盐角草，在0.05 mol L−1- 0.5 mol L−1 NaCl的浓度下接种这五株菌能显著提高盐角草种子萌发率（P <0.05），并且提高幼苗根长，芽长，鲜重（P <0.05）。（5）菌株EGI 60002T分离自囊果碱蓬，结合形态学、生理生化特性、细胞化学分析和系统发育分析进行多相分类，确定了该菌为Actinotalea属中的一个新种，命名为Actinotalea suaeda sp. nov. |
| 英文摘要 | Halophyte is regarded as suitable tool for the rehabilitation of saline soils. Exploiting the halophyte associated endophytic bacteria may aid in phytoremediation of saline soils. However, little is known about the diversity of endophytic bacterial communities in halophytes. Therefore, in this study, different species of halophytes grow in the same saline habitat and the same species of halophyte grow in different saline environment were selected, by using 454 pyrosequencing techniques and traditional culture methods, for the first time, the distribution of endophytic bacterial communities among different halophytes and different saline habitats were analyzed, and the functions of isolates were determined. Moreover, a novel species were classified. The major results are as follows: (1) Pyrosequencing results indicated that halophytes in the northern region of Xinjiang harbored diverse endophytic bacteria. Endophytic bacterial communities in the 16 plant species mainly included four phyla, which were Proteobacteria, Tenericutes, Actinobacteria and Firmicutes. Major class for Proteobacteria, Tenericutes, Actinobacteria and Firmicutes were Gammaproteobacteria, Mollicutes, Actinobacteria and Bacilli respectively. (2) In terms of plant species classification, colonial differences existed among plant species at perspectives of composition of bacterial taxa. Taking Tamarix ramosissima, Tamarix hispida, Reaumuria soongorica as example, endophytic bacterial communities in the three plant species were less diversified than these in other plant species; in the case of plant genus level, endophytic bacteria in different plant species but belonging to same plant genus exhibited similarity; as to plant family level, Actinobacteria and Proteobacteria comprised the main abundant phyla in the halophytes belonging to Chenopodiaceae; Proteobacteria comprised the main abundant phylum in the halophytes belonging to Zygophyllaceae; Tenericutes comprised the main abundant phylum in the halophytes belonging to Tamaricaceae; Proteobacteria, Fimicutes and Actinobacteria comprised the main abundant phyla in the halophytes belonging to Plumbaginaceae. (3) The analysis to distribution of endophytic bacteria in halophyte Salicornia europaea showed obvious dynamic changes. The host growth stages and growth habitat determined the endophytic bacterial communities. It has been indicated that the dominant endophytic bacteria during different growth periods in Fukang was related to Pseudomonas, which in Karamay were related to Pseudomonas and Delftia, Kushneria, Serratia and Pantoea, Pantoea, Erwinia, respectively. (4) Using a culture-dependent approach, 186 bacterial strains were isolated on agar. 16S rRNA sequences comparison exhibited that isolates distributed in 4 phyla, and 103 species. These isolates were tested for salt tolerance and plant growth-promoting traits. Two strains with nitrogen fixation ability, 57 strains with phosphate solubilisation ability, 25 strains with siderophore production ability, 13 strains can produce indole acetic acid, 9 strains with 1-aminocyclopropane-1-carboxylic acid deaminase activity, 16 strains can produce protease, 2 strains can produce lipase, 53 strains can produce cellulase. Plant growth-promoting activities were tested in axenically grown S. europaea seedlings at different NaCl concentrations (0.05–0.5 mol L−1). For Variovorax paradoxus XJB-YJ2, Bacillus endophyticus XJB-YJ4, Arthrobacter agilis XJB-YJ21, Bacillus tequilensis YJ-S4 and Planococcus rifietoensis YJ-ST4, significant plant growth-promoting activities were observed in Salicornia europaea under salt-stress conditions. (5) Strain EGI 60002T, was isolated from the halophyte Suaeda physophora. On the basis of morphological, physiological, chemotaxonomic data, and phylogenetic analysis, strain EGI 60002T has been classified as a novel species within the genus Actinotalea, for which the name Actinotalea suaedae sp. nov. is proposed. |
| 学科主题 | 生态学 |
| 语种 | 中文 |
| 源URL | [http://ir.xjlas.org/handle/365004/14925]  |
| 专题 | 新疆生态与地理研究所_研究系统_荒漠环境研究室 |
| 作者单位 | 中科院新疆生态与地理研究所 |
| 推荐引用方式 GB/T 7714 | 赵帅. 新疆北部主要盐生植物内生细菌多样性研究[D]. 北京. 中国科学院大学. 2015. |
入库方式： OAI收割
来源：新疆生态与地理研究所
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