蛋白质组学在水稻与微生物互作研究中的应用

应用蛋白质组学方法揭示植物与微生物的互作机制是当前植物病理学研究的热点之一。结合水稻感染水稻条纹病毒后的蛋白质组学分析经验,综述了蛋白质组学在水稻与微生物互作研究中的应用,包括水稻与真菌、细菌、病毒互作的蛋白组学和突变体蛋白质组学。在总结研究现状的基础上,提出了水稻与微生物互作的蛋白质组学研究中存在的问题,并对该领域的发展前景进行展望。     

主编导读

<正>本期主编导读主题：重要农艺性状功能基因及植物-微生物互作机制、病毒检测及疫苗研究、微生物与环境、多方位及混合式教学模式。重要农艺性状功能基因及植物-微生物互作机制阐明作物重要农艺性状分子控制的机理,以及植物-微生物(包括有益微生物和病原微生物)互作机制,能够为分子改良和设计重要农艺性状奠定理论基础,进而推动我国育种科学的可持续发展。     

miRNA介导植物-微生物互作中的调控作用及其研究进展北大核心CSCD

微生物与植物之间存在错综复杂的双向交流和串扰,植物与病原微生物互作直接影响寄主植物的生存状况,而植物和益生微生物互作则有利于宿主的生长和健康,共生微生物也会从中受益。不管是病原微生物还是有益微生物进入植物体内,植物miRNA都会迅速做出响应,同时微生物也可以产生miRNA样RNA(miRNA-likeRNA,milRNA)影响植物健康,可见miRNA(或milRNA)是植物与微生物互作过程中迅速响应的重要媒介分子,其内在机制研究近年来取得了许多进展。文中概述了植物-病原微生物、植物-益生微生物互作中miRNA的调控作用,重点阐述了植物miRNA在植物-病原微生物互作过程中对寄主植物抗病性的调控作用和植物-益生微生物互作过程中对宿主植物生长发育及代谢的调控,以及真菌milRNA对寄主植物的跨界调控作用。     

2016年动物胃肠道微生物组研究十大亮点成果

动物胃肠道微生物对生产性能提高具有重要的作用,因此营养、微生物组与生产表型的互作研究已经成为国际研究热点。综述了2016年动物胃肠道微生物组学研究取得的十项重要成果,这些成果通过组学方法,研究了瘤胃纤维分解菌和尿素分解菌的功能基因多样性,揭示了微生物群落与日粮营养素、宿主基因型、环境的互作关系,阐明了反刍动物生产表型相关的瘤胃微生物种类和功能;首次构建猪肠道微生物组参考基因集,解析猪全肠道黏膜微生物组成,阐明了猪增重相关肠道微生物种类。这十大亮点成果将为国内动物营养学家开展动物胃肠道微生物组学研究提供参考。     

分子微生物生态学及其研究进展

分子微生物生态学是分子生物学实验技术应用于微生物生态学研究领域而发展形成的一门交叉学科,在研究微生物生态系统组成结构、功能的分子机理以及微生物与生物和非生物环境之间相互关系等方面显示了巨大的潜力．十几年来分子微生物生态学研究所取得的成就证明：分子生物学研究技术向微生物生态学领域的不断渗透,为微生物生态学研究领域注入了新的活力,尤其在微生物多样性、微生物区系分子组成及变化规律以及微生物系统进化研究方面取得了重大突破．本文根据近年分子微生物生态学的研究进展,就分子微生物生态学概念的提出、发展历程、主要研究领域、主要研究方法以及未来研究热点领域作以简要综述。     

微生物代谢国家重点实验室

正微生物代谢国家重点实验室(上海交通大学)于2011年获准建设。实验室面向微生物代谢科学前沿和产业重大需求,探索微生物合成与分解代谢的机理,揭示微生物代谢活动的生理功能、调节网络和互作方式,力求科学探索微生物细胞工厂的内在驱动力,服务于现代生物产业的转型升级,实现微生物代谢潜能的优化释放。实验室设有合成代谢、分解代谢、代谢互作三大研究方向,发挥多学科交叉优势,在微生物表观遗传学、环境微生物学、微生态与健康、天然产物生物合成与合成生物学等众多研究领域成绩斐然:DNA硫修饰作为原创性研     

昆虫共生微生物：研究进展与展望

昆虫共生微生物是指与昆虫宿主建立持久互作关系的微生物，这些微生物分布于昆虫的体表、肠道、血腔或者细胞内，参与调节宿主昆虫的多种生理功能。昆虫-共生微生物互作研究涉及多个学科领域的交叉。深入研究昆虫共生微生物的功能及其与宿主的互作关系不仅有助于阐明重要的生命科学机理，还将为害虫治理和虫传病害的防控以及益虫的有效利用提供新的思路和方法。近年来，我国学者在昆虫微生物组研究领域取得显著进展，在多个研究方向取得重要成果。本文概述了国内外昆虫共生微生物研究的最新进展，介绍了本专辑论文的主要研究内容，并提出了值得关注的3个研究方向：(1)昆虫细胞内共生微生物的功能；(2)昆虫调控共生微生物丰度和传播的机制；(3)昆虫共生微生物的遗传改造和应用。     

植物微生物组生态功能与群落构建过程研究进展

植物各个器官表面及内部定殖着高度多样化的微生物群落,这些微生物与植物长期共进化,作为宿主植物的“共生功能体”(holobiont)在植物生长发育、养分吸收、病害抵御和环境胁迫适应性等方面发挥了重要作用。得益于近10年来多组学技术的发展和应用,有关植物微生物群落的多样性、组成和功能特征、群落构建的驱动因素和植物–微生物互作机制等方面研究取得了一系列重要进展。然而,与土壤微生物组相比,目前对植物微生物组的认识及其应用尚且不足。本文系统总结了植物微生物组的组成特征,植物微生物在调节植物生长发育、促进养分吸收、提高病害抵御能力及环境胁迫适应性等方面的功能及作用机制,从宿主选择、环境因子以及生物互作3个方面总结了驱动植物微生物群落构建的因素,并着重阐述了植物–微生物互作如何塑造植物微生物群落以及如何调节对植物的有益功能。此外,我们对未来植物微生物组研究和应用面临的挑战进行了展望,如核心微生物组挖掘和合成群落构建,植物–微生物互作的分子调控机制,植物微生物群落水平上的互作机制等。深入理解植物微生物群落特征、生态功能以及构建过程对于精准调控植物微生物组以提高植物适应性和生产力以及维持生态系统健康具有...     

微生物在食品工业中的热点应用及其进展

微生物在食品工业中得到了越来越广泛的应用。对其主要的研究热点作了综述。主要包括冰核细菌、益生菌、微生物风味剂、微生物防腐剂、微生物增稠剂、微生物油脂等方面。展现出了微生物在食品工业中的应用前景。     

影响微生物互作的重要基因研究进展：以大肠杆菌为例

微生物在自然界中广泛存在,微生物间的相互作用对群落结构和功能有重要影响。目前已经对微生物相互作用的机制给予了很大的关注,通过高通量测序技术和统计学分析方法的结合可以定位获得影响菌株互作的重要基因。为了深入研究微生物相互作用的遗传机制,本文以大肠杆菌(Escherichia coli)为例,综述了与大肠杆菌运动性、耐药性、营养物质吸收和代谢调节相关的基因在互作条件下发挥的作用,并从这几个方面分别阐述了大肠杆菌互作遗传机制。总之,这些基因在大肠杆菌与其他微生物互作中发挥重要作用,同时增强了对细菌互作机制的理解,为今后研究更复杂的微生物群落互作遗传机制奠定了理论基础。     

Ice Nucleation Activity in Lichens

A newly discovered form of biological ice nucleus associated with lichens is described. Ice nucleation spectra of a variety of lichens from the southwestern United States were measured by the drop-freezing method. Several epilithic lichen samples of the genera Rhizoplaca, Xanthoparmelia, and Xanthoria had nuclei active at temperatures as warm as −2.3°C and had densities of 2.3 × 10⁶ to more than 1 × 10⁸ nuclei g⁻¹ at −5°C (2 to 4 orders of magnitude higher than any plants infected with ice nucleation-active bacteria). Most lichens tested had nucleation activity above −8°C. Lichen substrates (rocks, plants, and soil) showed negligible activity above −8°C. Ice nucleation-active bacteria were not isolated from the lichens, and activity was not destroyed by heat (70°C) or sonication, indicating that lichen-associated ice nuclei are nonbacterial in origin and differ chemically from previously described biological ice nuclei. An axenic culture of the lichen fungus Rhizoplaca chrysoleuca showed detectable ice nucleation activity at −1.9°C and an ice nucleation density of 4.5 × 10⁶ nuclei g⁻¹ at −5°C. It is hypothesized that these lichens, which are both frost tolerant and dependent on atmospheric moisture, derive benefit in the form of increased moisture deposition as a result of ice nucleation.     

Ice Nucleation Induced by Pseudomonas syringae

Broth cultures of suspensions of Pseudomonas syringae isolated from decaying alder leaves (Alnus tenuifolia) were found to freeze at very warm (-1.8 to -3.8 C) temperatures. The initiation of freezing appears associated with the intact cell and not with extracellular material. Chemical treatments and physical destruction of the cell destroy activity. Bacteria must be in concentrations of approximately 10(6)/ml before freezing at warm temperatures occurs.     

The Ice Nucleation Gene from Pseudomonas syringae as a Sensitive Gene Reporter for Promoter Analysis in Zymomonas mobilis

The expression of the ice nucleation gene inaZ from Pseudomonas syringae in Zymomonas mobilis strains under the control of three different promoters was investigated to establish the utility of the gene as a reporter and examine the possible use of the organism as a source of ice nuclei for biotechnological applications. A promoterless version of the inaZ gene was placed under the control of three different promoters: P(infpdc) (pyruvate decarboxylase), a homologous strong promoter from Z. mobilis; P(infbla) ((beta)-lactamase) of plasmid pBR325; and P(infhrpR), the promoter of hrpR, a regulatory gene from P. syringae pv. phaseolicola. The apparent strengths of all three promoters, measured by quantifying the ice nucleation activity at -9 deg C, were lower in Z. mobilis than in Escherichia coli. The levels of ice nucleation activity expressed under the P(infpdc) promoter were significantly higher than those obtained with the two heterologous promoters in Z. mobilis. Plasmid pCG4521 (RK2 replicon) gave much lower levels of ice nucleation activity when propagated in strain uvs-51, a plasmid instability mutant of Z. mobilis, compared with the wild-type strain. The ice nucleation activity in Z. mobilis cultures showed unusual partitioning in that the culture supernatants obtained after low-speed centrifugation contained the majority of ice nuclei. Analysis of the ice nucleation spectra revealed that the cell pellets contained both "warm" and "cold" nuclei, while the culture supernatant contained primarily cold nuclei, suggesting that the cold nucleus activity may be extracellular. However, all nucleation activity was retained by 0.22-(mu)m-pore-size filters.     

Large-scale Production and Purification of an Erwinia ananas Ice Nucleation Protein and Evaluation of Its Ice Nucleation Activity

The ice nucleation-active protein of Erwinia ananas IN-10 (inaA protein) was over-expressed as inclusion bodies in Escherichia coli in a yield of 15.3 mg of inaA protein from 60 mg of bacterial cells on a dry-matter basis. The inaA protein was purified from the inclusion bodies by solubilization with detergents to obtain a protein preparation free from sugar and lipid. This preparation had a distinct ice nucleation activity, indicating that the inaA protein per se is able to act as a nucleus.     

Reduced Pressure Ice Fog Technique for Controlled Ice Nucleation during Freeze-Drying

A method to achieve controlled ice nucleation during the freeze-drying process using an ice fog technique was demonstrated in an earlier report. However, the time required for nucleation was about 5 min, even though only one shelf was used, which resulted in Ostwald ripening (annealing) in some of the vials that nucleated earlier than the others. As a result, the ice structure was not optimally uniform in all the vials. The objective of the present study is to introduce a simple variation of the ice fog method whereby a reduced pressure in the chamber is utilized to allow more rapid and uniform freezing which is also potentially easier to scale up. Experiments were conducted on a lab scale freeze dryer with sucrose as model compound at different concentration, product load, and fill volume. Product resistance during primary drying was measured using manometric temperature measurement. Specific surface area of the freeze-dried cake was also determined. No difference was observed either in average product resistance or specific surface area for the different experimental conditions studied, indicating that with use of the reduced pressure ice fog technique, the solutions nucleated at very nearly the same temperature (−10°C). The striking feature of the “Reduced Pressure Ice Fog Technique” is the rapid ice nucleation (less than a minute) under conditions where the earlier procedure required about 5 min; hence, effects of variable Ostwald ripening were not an issue.     

一种新型的报告基因—冰核基因

冰核基因 (ＩｃｅＮｕｃｌｅａｔｉｏｎＡｃｔｉｖｅｇｅｎｅ ,ＩＮＡｇｅｎｅ)是从冰核细菌中克隆的编码冰核蛋白的基因 ,它编码的冰核蛋白具有很强的冰核活性。当ｉｎａ基因与目的基因一起转入生物体后 ,可以通过冰核活性的测定来检测目的基因是否表达。冰核基因与通常的报告基因有着根本意义上的不同 ,它对信号的检测不是由于酶的催化反应 ,而是一种物理过程 (水的液 固状态的改变 )。ｉｎａ基因克服了其它报告基因的一些缺点 ,扩大了报告基因应用范围[1] 。现在 ,已经有很多研究植物 细菌相互作用的实验室应用ｉｎａ基因作为报告基因[4]…     

Ice Nucleation Activity in Fusarium acuminatum and Fusarium avenaceum

Twenty fungal genera, including 14 Fusarium species, were examined for ice nucleation activity at −5.0°C, and this activity was found only in Fusarium acuminatum and Fusarium avenaceum. This characteristic is unique to these two species. Ice nucleation activity of F. avenaceum was compared with ice nucleation activity of a Pseudomonas sp. strain. Cumulative nucleus spectra are similar for both microorganisms, while the maximum temperatures of ice nucleation were −2.5°C for F. avenaceum and −1.0°C for the bacteria. Ice nucleation activity of F. avenaceum was stable at pH levels from 1 to 13 and tolerated temperature treatments up to 60°C, suggesting that these ice nuclei are more similar to lichen ice nuclei than to bacterial ones. Ice nuclei of F. avenaceum, unlike bacterial ice nuclei, pass through a 0.22-μm-pore-size filter. Fusarial nuclei share some characteristics with the so-called leaf-derived nuclei with which they might be identified: they are cell free and stable up to 60°C, and they are found in the same kinds of environment. Highly stable ice nuclei produced by fast-growing microorganisms have potential applications in biotechnology. This is the first report of ice nucleation activity in free-living fungi.     

Type I Antifreeze Proteins Enhance Ice Nucleation above Certain Concentrations

In this study, we examined the effects that antifreeze proteins have on the supercooling and ice-nucleating abilities of aqueous solutions. Very little information on such nucleation currently exists. Using an automated lag time apparatus and a new analysis, we show several dilution series of Type I antifreeze proteins. Our results indicate that, above a concentration of ∼8 mg/ml, ice nucleation is enhanced rather than hindered. We discuss this unexpected result and present a new hypothesis outlining three components of polar fish blood that we believe affect its solution properties in certain situations.