High throughput RNA sequencing utility for diagnosis and prognosis in colon diseases

RNA sequencing is the use of hight hroughput next generation sequencing technology to survey, characterize, and quantify the transcriptome of a genome. RNA sequencing has been used to analyze the pathogenesis of several malignancies such melanoma, lung cancer, and colorectal cancer. RNA sequencing can identify differential expression of genes(DEG's), mutated genes, fusion genes, and gene isoforms in disease states. RNA sequencing has been used in the investigation of several colorectal diseases such as colorectal cancer, inflammatory bowel disease(ulcerative colitis and Crohn's disease), and irritable bowel syndrome.

High Throughput Sequencing of circRNAs in Tomato Leaves Responding to Multiple Stresses of Drought and Heat

Our aim is to study the roles of a new emerging group of non-coding RNAs, circRNAs, in tomato(Solanum lycopersicum L.) plants grown at the combination of drought and heat, two of the most usual stress conditions known to frequently happen in field. Tomato seedlings from cultivar‘Jinling Meiyu’ were treated without stresses(control), at water shortage, high temperature and subjected the multiple stresses. In total, 467 circRNAs were identified with 87.82% from exon using high throughput sequencing technology. Among the circRNAs, 70 were from chr1 with the range from 23 to 49 from the other chromosomes. In detail, 156 circRNAs were shared in the four libraries, while 21, 17 and 36 circRNAs were only shown in drought, heat and multiple stresses libraries, respectively. Through a differential expression analysis, four, seven and nine circRNAs were differentially regulated in tomato at drought, heat and multiple stresses as compared with control. These circRNAs played roles on photosynthesis, starch and sucrose metabolism, RNA transport, RNA degradation, spliceosome, ribosome, etc. Our study underlined the potential role of circRNAs involved in the abiotic stress response in tomato, which might pave the way for studying biological roles of circRNAs responding to multiple stresses in plants.

Microbial Diversity in Rhizosphere Soil of Cotinus coggygria Based on High Throughput Sequencing

In order to reveal the influence of different plant configurations on the microbial community structure and diversity in rhizosphere soil of Cotinus coggygria in Fragrant Hills park,the ITS+5.8S rDNA gene and 16S rDNA gene V3-V4 region sequencing analysis for fungi and bacteria,respectively,were conducted by high throughput sequencing(Illumina MiSeq).The results showed that the fungal diversity in the rhizosphere soil samples of C.coggygria in Fragrant Hills park in 2018 was significantly higher than that in 2016,and it was higher in the rhizosphere soil of healthy C.coggygria in Xunlupo than that in diseased ones in 2018.Verticillium dahliae,which is the causal agent of C.coggygria wilt,was detected in five soil samples.In 2018,the bacterial diversity in the rhizosphere soil of diseased C.coggygria in Xunlupo was the lowest,while it was the highest in the rhizosphere soil of healthy C.coggygria under Platycladus orientalis in Langfengting.

High-throughput Sequencing Technology and Its Application

Gene sequencing is a great way to interpret life, and high-throughput sequencing technology is a revolutionary technological innovation in gene sequencing researches. This technology is characterized by low cost and high-throughput data. Currently, high-throughput sequencing technology has been widely applied in multi-level researches on genomics, transcriptomics and epigenomics. And it has fundamentally changed the way we approach problems in basic and translational researches and created many new possibilities. This paper presented a general description of high-throughput sequencing technology and a comprehensive review of its application with plain, concisely and precisely. In order to help researchers finish their work faster and better, promote science amateurs and understand it easier and better.

Comparison of rumen archaeal diversity in adult and elderly yaks(Bos grunniens)using 16S rRNA gene high-throughput sequencing

This study was conducted to investigate the phylogenetic diversity of archaea in the rumen of adult and elderly yaks. Six domesticated female yaks, 3 adult yaks （（5.3±0.6） years old）, and 3 elderly yaks （（10.7±0.6） years old）, were used for the rumen contents collection. Illumina MiSeq high-throughput sequencing technology was applied to examine the archaeal composition of rumen contents. A total of 92 901 high-quality archaeal sequences were analyzed, and these were assigned to 2 033 operational taxonomic units （OTUs）. Among these, 974 OTUs were unique to adult yaks while 846 OTUs were unique to elderly yaks; 213 OTUs were shared by both groups. At the phylum level, more than 99% of the obtained OTUs belonged to the Euryarchaeota phylum. At the genus level, the archaea could be divided into 7 archaeal genera. The 7 genera （i.e., Methanobrevibacter, Methanobacterium, Methanosphaera, Thermogymnomonas, Methanomicrobiu, Meth- animicrococcus and the unclassified genus） were shared by all yaks, and their total abundance accounted for 99% of the rumen archaea. The most abundant archaea in elderly and adult yaks were Methanobrevibacterand Thermogymnomonas, respectively. The abundance of Methanobacteria （class）, Methanobacteriales （order）, Methanobacteriaceae （family）, and Methanobrevibacter （genus） in elderly yaks was significantly higher than in adult yaks. In contrast, the abundance of Ther-mogymnomonas in elderly yaks was 34% lower than in adult yaks, though the difference was not statistically significant. The difference in abundance of other archaea was not significant between the two groups. These results suggested that the structure of archaea in the rumen of yaks changed with age. This is the first study to compare the phytogenetic differences of rumen archaeal structure and composition using the yak model.

Genome-wide identification of RNA editing in seven porcine tissues by matched DNA and RNA high-throughput sequencing

Background: RNA editing is a co/posttranscriptional modification mechanism that increases the diversity of transcripts, with potential functional consequences. The advent of next-generation sequencing technologies has enabled the identification of RNA edits at unprecedented throughput and resolution. However, our knowledge of RNA editing in swine is still limited.Results: Here, we utilized RES-Scanner to identify RNA editing sites in the brain, subcutaneous fat, heart, liver,muscle, lung and ovary in three 180-day-old Large White gilts based on matched strand-specific RNA sequencing and whole-genome resequencing datasets. In total, we identified 74863 editing sites, and 92.1% of these sites caused adenosine-to-guanosine(A-to-G) conversion. Most A-to-G sites were located in noncoding regions and generally had low editing levels. In total, 151 A-to-G sites were detected in coding regions(CDS), including 94 sites that could lead to nonsynonymous amino acid changes. We provide further evidence supporting a previous observation that pig transcriptomes are highly editable at PRE-1 elements. The number of A-to-G editing sites ranged from 4155(muscle) to 25001(brain) across the seven tissues. The expression levels of the ADAR enzymes could explain some but not all of this variation across tissues. The functional analysis of the genes with tissuespecific editing sites in each tissue revealed that RNA editing might play important roles in tissue function.Specifically, more pathways showed significant enrichment in the fat and liver than in other tissues, while no pathway was enriched in the muscle.Conclusions: This study identified a total of 74863 nonredundant RNA editing sites in seven tissues and revealed the potential importance of RNA editing in tissue function. Our findings largely extend the porcine editome and enhance our understanding of RNA editing in swine.

Microbial diversity in Huguangyan Maar Lake of China revealed by high-throughput sequencing

Huguangyan Maar Lake is a typical maar lake in the southeast of China. It is well preserved and not disturbed by anthropogenic activities. In this study, microbial community structures in sediment and water samples from Huguangyan Maar Lake were investigated using a high-throughput sequencing method. We found significant differences between the microbial community compositions of the water and the sediment. The sediment samples contained more diverse Bacteria and Archaea than did the water samples. Actinobacteria, Betaproteobacteria, Cyanobacteria, and Deltaproteobacteria predominated in the water samples while Deltaproteobacteria, Anaerolineae, Nitrospira, and Dehalococcoidia were the major bacterial groups in the sediment. As for Archaea, Woesearchaeota (DHVEG-6), unclassified Archaea, and Deep Sea Euryarchaeotic Group were detected at higher abundances in the water, whereas the Miscellaneous Crenarchaeotic Group, Thermoplasmata, and Methanomicrobia were significantly more abundant in the sediment. Interactions between Bacteria and Archaea were common in both the water column and the sediment. The concentrations of major nutrients (NO^3-, PO4^3-, SiO3^2- and NH4^+) shaped the microbial population structures in the water. At the higher phylogenetic levels including phylum and class, many of the dominant groups were those that were also abundant in other lakes;however, novel microbial populations (unclassified) were often seen at the lower phylogenetic levels. Our study lays a foundation for examining microbial biogeochemical cycling in sequestered lakes or reservoirs.

Characterization of Bacterial Communities Associating with Larval Development of Yesso Scallop(Patinopecten yessoensisis Jay, 1857) by High-Throughput Sequencing

Bacterial community presumably plays an essential role in inhibiting pathogen colonization and maintaining the health of scallop larvae, but limiting data are available for Yesso scallop(Patinopecten yessoensisis Jay, 1857) larval development stages. The aim of this study was to characterize and compare the bacterial communities associating with Yesso scallop larval development at fertilized egg S1, trochophora S2, D-shaped larvae S3, umbo larvae S4, and juvenile scallop S5 stages by Illumina high-throughput sequencing. Genomic DNA was extracted from the larvae and their associating bactera, and a gene segment covering V3-V4 region of 16 S r RNA gene was amplified and sequenced using an Illumina Miseq sequencer. Overall, 106760 qualified sequences with an average length of 449 bp were obtained. Sequences were compared with those retrieved from 16 S r RNA gene databases, and 4 phyla, 7 classes, 15 orders, 21 families, 31 genera were identified. Proteobacteria was predominant phylum, accounting for more than 99%, at all 5 larval development stages. At genus level, Pseudomonas was dominant at stages S1(80.60%), S2(87.77%) and S5(68.71%), followed by Photobacterium(17.06%) and Aeromonas(1.64%) at stage S1, Serratia(6.94%), Stenotrophomonas(3.08%) and Acinetobacter(1.2%) at stage S2, Shewanella(25.95%) and Pseudoalteromonas(4.57%) at stage S5. Moreover, genus Pseudoalteromonas became dominant at stages S3(44.85%) and S4(56.02%), followed by Photobacterium(29.82%), Pseudomonas(11.86%), Aliivibrio(8.60%) and Shewanella(3.39%) at stage S3, Pseudomonas(18.16%), Aliivibrio(14.29%), Shewanella(4.11%), Psychromonas(4.04%) and Psychrobacter(1.81%) at stage S4. From the results, we concluded that the bacterial community changed significantly at different development stages of Yesso Scallop larvae.

High-throughput sequencing exclusively identified a novel Torque teno virus genotype in serum of a patient with fatal fever

Torque teno virus(TTV) has been found to be prevalent world-wide in healthy populations and in patients with various diseases, but its etiological role has not yet been determined. Using high-throughput unbiased sequencing to screen for viruses in the serum of a patient with persistent high fever who died of suspected viral infection and prolonged weakness, we identified the complete genome sequence of a TTV(isolate Hebei-1). The genome of TTV-Hebei-1 is 3649 bp in length, encoding four putative open reading frames, and it has a G+C content of 49%. Genomic comparison and a BLASTN search revealed that the assembled genome of TTV-Hebei-1 represented a novel isolate, with a genome sequence that was highly heterologous to the sequences of other reported TTV strains. A phylogenetic tree constructed using the complete genome sequence showed that TTV-Hebei-1 and an uncharacterized Taiwan Residents strain, TW53A37, constitute a new TTV genotype. The patient was strongly suspected of carrying a viral infection and died eventually without any other possible causes being apparent. No virus other than the novel TTV was identified in his serum sample. Although a direct causal link between the novel TTV genotype infection and the patient's disease could not be confirmed, the findings suggest that surveillance of this novel TTV genotype is necessary and that its role in disease deserves to be explored.

Differential mRNA expression profiling of oral squamous cell carcinoma by high-throughput RNA sequencing

Differentially expressed genes are thought to regulate the development and progression of oral squamous cell carcinomas （OSCC）. The purpose of this study was to screen differentially expressed mRNAs in OSCC and matched paraneoplastic normal tissues, and to explore the intrinsic mechanism of OSCC development and progres- sion. We obtained the differentially expressed mRNA expression profiles in 10 pairs of fresh-frozen OSCC tissue specimens and matched paraneoplastic normal tissue specimens by high-throughput RNA sequencing. By using Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway enrichment analyses, the functional significance of the differentially expressed genes were analyzed. We identified 1,120 sig- nificantly up-regulated mRNAs and 178 significantly down-regulated mRNAs in OSCC, compared to normal tissue. The differentially expressed mRNAs were involved in 20 biological processes and 68 signal pathways. Compared to adjacent normal tissue, the expression of MAGEAll was up-regulated; TCHH was down-regulated. These find- ings were verified by real-time PCR. These differentially expressed mRNAs may function as oncogenes or tumor suppressors in the development and progression of OSCC. This study provides novel insights into OSCC. However, further work is needed to determine if these differentially expressed mRNAs have potential roles as diagnostic bio- markers and candidate therapeutic targets for OSCC.

Characterization of Bacterial Community Associated with Four Organs of the Yesso Scallop (Patinopecten yessoensis) by High-Throughput Sequencing

We used Illumina high-throughput sequencing of PCR-amplified V3-V4 16 S rRNA gene regions to characterize bacterial communities associated with the adductor muscles, gills, gonads and intestines of the Yesso scallop(Patinopecten yessoensis) from waters around Zhangzidao, Dalian, China. Overall, 421,276 optimized reads were classified as 25 described bacterial phyla and 308 genera. Firmicutes, Proteobacteria, Tenericutes, Bacteroidetes, Chlamydiae and Spirochaetae accounted for > 97% of the total reads in the four organs. The bacterial 16 S rDNA sequences assigned to Firmicutes and Proteobacteria were abundant in the adductor muscles, gills and gonads; while reads from Tenericutes were dominant in the intestines, followed by those from Firmicutes, Chlamydiae, Proteobacteria and Bacteroidetes. At the genus level, the dominant genera in the adductor muscles, gills and gonads appeared to be Bacillus, Enterococcus and Lactococcus, whereas Mycoplasma was dominant in the intestines. The relative abundances of Bacillus, Enterococcus, Lactococcus, Alkaliphilus, Raoultella, Paenibacillus and Oceanobacillus were significantly lower in the intestine than in the other three organs. Cluster analysis and principal coordinates analysis of the operational taxonomy units profile revealed significant differences in the bacterial community structure between the intestine and the other three organs. Taken together, these results suggest that scallops have intestine-specific bacterial communities and the adductor muscles, gills and gonads harbor similar communities. The difference in the bacterial community between organs may relate to unique habitats, surroundings, diet and their respective physiological functions.

Characterization of root-associated bacterial community structures in soybean and corn using locked nucleic acid(LNA) oligonucleotide-PCR clamping and 454 pyrosequencing

supported in part by grants from the Strategic Priority Research Program of Chinese Academy of Sciences （XDB15010103）;the National Natural Science Foundation of China （41201247）

Gelatin filter capture-based high-throughput sequencing analysis of microbial diversity in haze particulate matter

Airborne particulate matter(PM),especially PM2.5,can be easily adsorbed by human respiratory system.Their roles in carrying pathogens for spreading epidemic diseases has attracted great concern.Herein,we developed a novel gelatin filter-based and culture-independent method for investigation of the microbial diversity in PM samples during a haze episode in Tianjin,China.This method involves particle capture by gelatin filters,filter dissolution for DNA extraction,and high-throughput sequencing for analysis of the microbial diversity.A total of 584 operational taxonomic units(OTUs)of bacteria and 370 OTUs of fungi at the genus level were identified during hazy days.The results showed that both bacterial and fungal diversities could be evaluated by this method.This study provides a convenient strategy for investigation of microbial biodiversity in haze,facilitating accurate evaluation of airborne epidemic diseases.

High-throughput sequencing analysis of differentially expressed mi RNAs and target genes in ischemia/reperfusion injury and apelin-13 neuroprotection

miRNAs regulate a variety of biological processes through pairing-based regulation of gene expression at the 3＇ end of the noncoding region of the target miRNA, miRNAs were found to be abnormally expressed in ischemia/reperfusion injury models. High-throughput sequencing is a recently developed method for sequencing miRNAs and has been widely used in the analysis of miRNAs. In this study, ischemia/reperfusion injury models were intracerebroventricularly injected with 50 pg/kg apelin-13. High-throughput sequencing showed that 357 known miRNAs were differentially expressed among rat models, among which 78 changed to 〉 2-fold or 〈 0.5-fold. Quantita- tive real-time polymerase chain reaction was selected to confirm the expression levels of four miRNAs that were differentially expressed, the results of which were consistent with the results of high-throughput sequencing. Gene Ontology analysis revealed that the predicted targets of the different miRNAs are particularly associated with cellular process, metabolic process, single-organism process, cell, and binding. Kyoto Encyclopedia of Gene and Genome analysis showed that the target genes are involved in metabolic pathways, mitogen-ac- tivated protein kinase signaling pathway, calcium signaling pathway, and nuclear factor-KB signaling pathway. Our findings suggest that differentially expressed miRNAs and their target genes play an important role in ischemia/reperfusion injury and neuroprotection by apelin-13.

Genetic evaluation and testing for hereditary forms of cancer in the era of next-generation sequencing

The introduction of next-generation sequencing(NGS) technology in testing for hereditary cancer susceptibility allows testing of multiple cancer susceptibility genes simultaneously. While there are many potential benefits to utilizing this technology in the hereditary cancer clinic, including efficiency of time and cost, there are also important limitations that must be considered. The best panel for the given clinical situation should be selected to minimize the number of variants of unknown significance. The inclusion in panels of low penetrance or newly identified genes without specific actionability can be problematic for interpretation.Genetic counselors are an essential part of the hereditary cancer risk assessment team, helping the medical team select the most appropriate test and interpret the often complex results. Genetic counselors obtain an extended family history, counsel patients on the available tests and the potential implications of results for themselves and their family members(pre-test counseling), explain to patients the implications of the test results(post-test counseling), and assist in testing family members at risk.

抗虫转基因水稻及其杂交水稻对土壤微生物群落多样性与组成的影响

微生物是土壤物质循环与肥力演变的驱动者,其群落组成关系到土壤微生态系统的稳定与可持续性。对抗虫转基因水稻土壤微生物群落变化的研究是其环境安全性评价的重要内容。本研究基于细菌16S rRNA基因和真菌ITS基因的高通量测序,分析了田间试验中抗虫转基因水稻‘MFB’及其转基因杂交水稻‘闽丰A/MFB’‘天丰A/MFB’和‘谷丰A/MFB’与非转基因常规水稻‘闽恢3301’及杂交水稻‘天优华占’的土壤微生物群落多样性与组成的差异,并得出以下结果。首先,与两个非转基因水稻品种相比,抗虫转基因水稻及转基因杂交水稻均能显著增产(P<0.05)。同时,高通量测序结果表明,除水稻成熟期的土壤真菌群落外,与‘闽恢3301’相比‘MFB’的土壤细菌或真菌群落的α-多样性指数Chao1、Observed_species和Shannon均有所提高,且分别在水稻成熟期或分蘖期达到显著性水平(P<0.05);水稻齐穗期转基因杂交水稻‘闽丰A/MFB’‘天丰A/MFB’和‘谷丰A/MFB’的土壤细菌及真菌群落的多样性指数Shannon均介于‘MFB’与‘天优华占’之间;微生物群落β-多样性分析结果表明,本田间试验中不同品种水稻土壤细菌或真菌的群落组成均没有显著差异。但与‘闽恢3301’相比,稻田土壤细菌中丰度最高的变形菌门的相对丰度在‘MFB’土壤中明显增加,且在水稻分蘖期及成熟期达显著水平(P<0.05),而土壤真菌中丰度最高的子囊菌门的相对丰度在‘MFB’土壤中明显减少,且在水稻分蘖期及齐穗期差异显著(P<0.05);水稻齐穗期‘闽丰A/MFB’‘天丰A/MFB’和‘谷丰A/MFB’的土壤变形菌门或子囊菌门的相对丰度也均介于‘MFB’与‘天优华占’之间。此外,通过对微生物群落的功能组成预测可见,随水稻生长,‘MFB’与‘闽恢3301’的土壤细菌群落功能组成间差异存在增大的趋势。综上所述,本研究田间试验中,抗虫转基因水稻及其转基因杂交水稻在增产的同时提高了稻田土壤细菌或真菌群落的多样性,改变了主要细菌或真菌种类的相对丰度,但对细菌或真菌的群落及功能组成的影响不显著。

间作黄芪对当归根际土壤微生物的影响

目的:探讨根际土壤微生物对中药材种植模式的响应方式。方法:以间作黄芪及单作下当归根际土壤为研究对象,基于高通量测序技术,分析土壤微生物在不同季节及种植模式下群落组成及功能的差异。结果:间作下Chao1指数、ACE指数高于单作,变形菌门、放线菌门、酸杆菌门、绿弯菌门和芽单胞菌门为间作下的优势菌门,芽单胞菌门的相对丰度在间作下高于单作。11月间作下γ变形菌纲、7月间作下全噬菌纲的丰度显著高于单作。KEGG功能预测表明,在不同时间及间作下根际土壤细菌与细胞过程、环境信息处理、遗传信息处理、代谢功能下属的23类二级功能基因的相对丰度存在显著差异;参与氮循环的功能基因K00371(narH/narY/nxrB)、(K00374 narI/narV)等OTU数在间作下显著高于单作;不同门、纲在间作下的共生网络比单作下连接紧密且更复杂。结论:当归间作黄芪影响土壤细菌群落组成,增加其丰富度及功能的丰富性,影响土壤氮循环能力,促进土壤微生物间的交互作用。

油梨根际土壤微生物群落及其共生网络对根腐病的响应

【目的】为研发根腐病绿色综合防控技术提供理论依据,有效推进油梨树种产业发展。【方法】本研究以百色市林业科学研究所的健康和根腐病发病油梨植株根际土壤为研究对象,并利用基于16S核糖体RNA(rRNA)和内部转录间隔区(ITS)扩增子高通量测序技术,分析健康和染病植株根际细菌和真菌群落结构、组成及多样性差异,比较细菌和真菌群落结构及其相互作用,确定土壤病原菌和有益菌的变化。【结果】染病植株相对于健康植株,根际细菌和真菌群落结构和多样性均没有显著性变化。变形菌门Proteobacteria、酸杆菌门acidobacteria、放线菌门actinobacteria、拟杆菌门bacteroidetes和绿弯菌门chloroflexi是油梨根际土壤优势细菌类群,子囊菌门ascomycota和担子菌门basidiomycota是油梨根际土壤优势真菌类群。在门分类水平、纲分类水平以及属分类水平上,细菌和真菌群落组成有明显的变化,但随着分类水平降低,群落组成变化越明显。此外,健康和染病油梨根际细菌群落α多样性显著高于真菌群落,而健康与染病之间细菌群落结构差异小于真菌。细菌物种之间的相互作用比真菌网络物种间的相互作用更紧密,并且负连接百分比和关节类群数量更多,细菌网络的稳定性更高。同样,油梨根际土壤细菌群落相对于真菌群落表现出更高的生态位宽度和生态位重叠。对根腐病有反应的细菌和真菌,如芽孢杆菌Bacillus、假单胞杆菌pseudomonas和溶杆菌lysobacter和球囊菌纲glomeromycetes,由于其在染病油梨根际土壤中的相对丰度均高于健康土壤,可以被视为相关的生物防治菌。【结论】根腐病并不会使油梨根际细菌和真菌群落结构和多样性发生显著性变化,但会使得一些有益菌的相对丰度增加,并且细菌比真菌对根腐病具有更高的抵抗力。

苯醚甲环唑胁迫下农田土壤微生物群落和多样性分析

为研究三唑类杀菌剂苯醚甲环唑(dif)施用后土壤中微生物群落结构的响应变化,通过模拟生产中的施用剂量,监测35 d后土壤的理化性质并利用高通量测序技术分析土壤中细菌和真菌的群落组成变化,通过db-RDA分析建立环境因子与微生物群落响应关系。研究结果显示,随着dif施用浓度的增加,土壤中有机质(SOM)、总氮(TN)、碱解氮(AN)均有所提高,有效磷(AP)呈下降趋势,Alpha多样性指数中细菌Chao1、ACE和Shannon指数均低于未处理土壤,真菌Shannon指数高于未处理土壤;所有样本中细菌共检出31门、91纲、206目、315科、553属,真菌共检测出11门、34纲、79目、174科、370属;苯醚甲环唑施用浓度为50 mg/kg时,土壤细菌中变形菌门和拟杆菌门的相对丰度分别提高了14.2%和1.81%,酸杆菌门和绿弯菌门相对丰度分别降低了8.28%和3.44%,绝对优势菌属节杆菌属相对丰度下降7.85%,真菌中赤霉属和被孢霉属逐渐成为优势菌群;细菌的优势菌群中变形菌门与TN呈显著正相关,真菌优势菌门中子囊菌门与AN、TN和dif呈显著正相关,被孢霉门与SOM呈显著负相关;TN和AN对细菌的Shannon指数影响较大。以上说明,高浓度苯醚甲环唑的施用对土壤的理化性质以及微生物的丰富度和群落结构均产生了影响。

镉污染对滨海滩涂围垦区西兰花根际土壤细菌群落结构的影响

研究镉(Cd)污染对滩涂湿地围垦区西兰花根际土壤细菌群落结构的影响,探求有益于Cd污染农田土壤修复的耐Cd细菌菌群。采用Illumina Miseq高通量测序技术,分析Cd浓度分别为0,3.5,60 mg·kg^(-1)时对台州湾滩涂湿地围垦区西兰花根际土壤细菌群落结构和多样性指数的影响。结果表明:所有样品中检测到的细菌菌群分属于35门、97纲、205目、315科、506属。低浓度Cd污染时,西兰花根际土壤细菌Chao 1指数和Shannon指数与对照相比大幅度升高,而高浓度Cd污染时,土壤细菌Chao 1指数和Shannon均大幅度下降。随着Cd污染程度的增加,西兰花根际土壤放线菌门和浮霉菌门相对丰度呈一直下降的趋势,拟杆菌门和芽单胞菌门相对丰度呈一直升高的趋势。土壤变形菌门和髌骨菌门相对丰度呈先下降后上升的趋势,而土壤酸杆菌门、棒状杆菌门、疣微菌门、硝化螺旋菌门和厚壁菌门相对丰度呈先上升后下降的趋势。变形菌门、拟杆菌门、髌骨菌门和芽单胞菌门在高浓度Cd污染下为农田土壤细菌群落的主体。土壤罗思河小杆菌属相对丰度在低浓度Cd污染时呈下降趋势,而在高浓度Cd污染时呈升高趋势,土壤鞘氨醇单胞菌属的相对丰度在低浓度Cd污染时呈上升趋势,在高浓度Cd污染时呈下降趋势。土壤罗思河小杆菌属、马赛菌属、黄杆菌属和杜擀氏菌属可以被认为是西兰花根际土壤高抗Cd污染的细菌菌属。研究结果可为滨海滩涂地西兰花重金属污染土壤微生物修复提供依据。