中国植物弹状病毒研究进展

弹状病毒含有单链负义RNA基因组,寄主范围比较广泛,能侵染无脊椎动物、脊椎动物以及植物等寄主,对人类的健康、农作物产量和自然生态系统造成严重威胁。植物弹状病毒主要根据复制场所分为细胞质弹状病毒属Cytorhabdovirus和细胞核弹状病毒属Nucleorhabdovirus,其基因组由单股负链RNA组成。此外,Dichorhavirus和Varicosavirus病毒属是两个新鉴定的植物弹状病毒属,其特征是具有二分体基因组。本文着重介绍危害我国农作物的几类植物弹状病毒,对它们的病理学、病害流行、基因组信息以及传播媒介进行概述,为中国植物弹状病毒病害的研究提供理论依据。     

加拿大在特殊审查中澄清乙酰甲胺磷风险

<正>加拿大有害生物管理局(PMRA)在对有机磷杀虫剂乙酰甲胺磷进行了特殊审查后,提议允许乙酰甲胺磷继续登记使用。该特殊审查源于2003年欧盟基于对人类健康和环境影响的关切禁止了该杀虫剂的使用。关切包括了乙酰甲胺磷的急性膳食暴露,对非靶标陆生无脊椎动物、鸟类、哺乳动物以及水生生物的潜在风险。PMRA在审查中发现:在应用了风险减缓措     

章鱼胺的作用机理及其受体的研究进展

章鱼胺在无脊椎动物神经组织中可作为神经递质、神经激素或神经调节剂 ,它对昆虫的取食、迁飞和繁殖等生理过程起调节作用。章鱼胺受体作用机制是通过刺激腺苷酸环化酶系统和其它第二信使 ,从而产生各种生理效应。因此它们是高效、强选择性农药开发中生物合理设计的理想靶标。对章鱼胺的生物影响、作用机制、药理分类以及章鱼胺受体的生物学研究进展进行了综述 ,并讨论了章鱼胺受体系统中可能用于设计新农药先导分子的潜在途径与靶标。     

双酰胺类杀虫剂环境风险问题浅析

双酰胺类杀虫剂是一类优势明显的新型杀虫剂,防效卓越,持效期长,且与传统农药无交互抗性。然而,这类高生物活性杀虫剂的缺点也很明显:对环境中特定种类的非靶标生物毒性很高,在环境介质中的残留期很长,对生态系统的潜在风险较高。本文综述了双酰胺类杀虫剂的主要品种及其作用特点,国内外登记情况,及其对环境生物的生态毒理学研究进展等。双酰胺类杀虫剂对水生无脊椎动物、家蚕的潜在风险,乃至脊椎动物(鸟类、鱼类)的慢性风险均有待进一步开展深入研究与评估。同时,今后应继续加强双酰胺类农药使用后的环境风险监测,在发挥杀虫优势的同时避免或减少其对生态环境的污染和破坏。     

具有III型分泌系统的Pseudomonas moraviensis FP1761植物益生功能及其全基因组分析

 本研究从节瓜根际分离到一株具有防病促生功能的荧光类假单胞菌FP1761。该菌株对部分植物病原真菌和细菌具有拮抗能力,能够解钾、解有机磷和无机磷,可产生氨、蛋白酶、嗜铁素、吲哚乙酸。生物测定表明菌株FP1761可显著促进小麦生长。生理生化、平均核苷酸相似度、16S rDNA和多基因分析将FP1761鉴定为摩拉维亚假单胞菌(Pseudomonas moraviensis)。菌株FP1761基因组草图全长6.12 Mb,(G+C)含量为59.9%,共编码5467个基因序列。将该菌株与种内3个代表性菌株进行泛基因组和核心基因组分析,共产生 4 357个共有基因,菌株FP1761特有基因327个。利用antiSMASH对菌株次生代谢基因簇进行预测,发现其含有8个潜在的次生代谢产物基因簇。其中两个基因簇与嗜铁素pyoverdine合成相关,未见聚酮类合成基因。基因组分析发现,该菌株具有与病原性假单胞菌相似的III型分泌系统,但丢失了效应蛋白调控因子hrpS和转运相关的hrpH和hrpK1基因。对全基因组扫描,菌株FP1761仅保留了病原性假单胞菌的保守效应蛋白AvrE和HopAA1-1。FP1761是目前已发现的唯一具有III型分泌系统的摩拉维亚假单胞菌。本研究表明摩拉维亚假单胞菌FP1761具有潜在的植物防病促生功能,但其III型分泌系统与植物益生互作机制有待进一步解析。     

格氏线虫对高等动物的安全性——Ⅰ.对小白鼠的安全测试

在我国,随着对昆虫寄生性研究与应用工作的广泛开展,人们必定考虑寄生性线虫对高等动物、人以及其它有益生物(包括天敌昆虫)的安全性问题。在这一方面,国外曾进行过一些研究。Ignoffo等(1973)研究了寄生于蚊子的线虫Reesimermis nielseni Tsai and Grundman对鱼类和一些无脊椎动物的敏感性试验。结果证明其对鱼类是不感染的,对大多数水生无脊椎动物也是安全的。1974年,作者进一步测试了这种线虫对小白鼠和大白鼠的敏感性,证明其对实验动物不引起任何病变。据Poinar     

苏云金芽孢杆菌研究和开发的最新动向

第六届国际无脊椎动物病理学和微生物防治学术讨论会、第二届国际苏云金芽孢杆菌会议和第二十七届无脊椎动物病理学会年会于１９９４年８月２８日至９月２日在法国Ｍｏｎｔｐｅｌｉｅｒ召开。有５５个国家的５８０多人出席了会议，共收到学术论文近６００篇，出版了两卷论...     

昆虫基因组组装大小偏差的原因解析

为明确昆虫基因组组装大小产生偏差的原因,利用流式细胞术估测来自6目10科的21种常见农业昆虫的基因组大小,同时从动物基因组大小数据库收集和整理1 345个经流式细胞术估测的昆虫基因组大小信息,并从NCBI、GigaDB、DDBJ、i5k workspace@NAL、InsectBase和VectorBase等14个物种遗传信息数据网站获取536种昆虫的基因组组装信息进行比较分析。结果表明,收集的昆虫中有202种同时具有流式细胞术估测的基因组大小和基因组组装大小的信息,以更接近真实值的流式细胞术估测基因组大小为参照,比较发现其中42种昆虫的基因组组装大小偏大,98种昆虫的基因组组装大小偏小,而62种昆虫的基因组组装大小和经流式细胞术估测大小相似。基因组组装大小比经流式细胞术估测大小更大的物种,通过Wilcoxon秩和检验发现显著具有更多的重复序列,但与GC含量、contig N50及基因组测序和组装策略并无显著相关性。综合分析认为,在大多数情况下昆虫基因组组装大小更小,表明组装并不完整,但在重复序列占比较高的情况下,昆虫基因组的组装出现了冗余,导致组装大小更大。     

LmNotch基因在飞蝗翅发育中的功能分析

Notch是Notch信号通路中的受体蛋白,与配体结合后调控下游靶标基因的表达,在无脊椎动物和脊椎动物的发育和分化过程中发挥着重要的作用。本文以飞蝗为研究对象,利用转录组数据库搜索获得Notch信号通路受体基因LmNotch,并利用qRT-PCR对5龄飞蝗不同组织及不同发育时期翅芽组织中的LmNotch表达特性进行了分析。通过RNA干扰试验对其生物学功能进行分析,发现注射dsLmNotch的飞蝗有70%无法完成蜕皮过程,10%的飞蝗在蜕皮后出现翅紊乱表型。飞蝗翅芽石蜡切片的H&E染色结果表明,处理组翅上下两层表皮之间腔空间增大,新表皮无法完整形成。qRT-PCR检测其他翅发育相关基因表达发现,LmNotch表达量的下降影响翅发育相关基因Dpp、Omb、Yorkie以及翅特异表皮蛋白基因的表达。上述研究结果可为昆虫翅发育机制研究提供理论基础,同时为害虫生物防治提供潜在靶标。     

侵染梨的苹果茎痘病毒基因组序列及小RNA分析

苹果茎痘病毒(Apple stem pitting virus,ASPV)是危害梨(Pyrus spp.)和苹果(Malus spp.)的重要病毒。本研究采用小RNA深度测序技术获得了ASPV基因组的部分序列,在此基础上设计引物对该病毒基因组进行RT-PCR扩增,通过序列拼接得到1个来源于玉露香(Yuluxiang)梨的ASPV分离物(YLX)长度为9 291个核苷酸(nt)(不包括基因组5'末端约30个核苷酸)的基因组序列,该序列与已报道的13个ASPV分离物的基因组核苷酸序列相似性为71.6%~80.7%,与多个来自苹果的ASPV分离物系统进化关系较近。首次分析了来源于ASPV基因组的干扰性小RNA(siRNA),发现来源于ASPV基因组链和互补链的siRNA长度均以21 nt和22 nt为主,siRNA的5'端具有一定的碱基偏好性。本研究结果为深入了解ASPV的分子特性提供了重要信息。     

靶向G-四链体的抗番茄丛矮病毒卟啉类衍生物的筛选

植物病毒病给蔬菜生产带来很大影响,目前蔬菜病毒防控主要采用非药剂措施,广谱抗病毒剂效果有限,需要基于新的药物靶点开发新的病毒抑制剂。G-四链体(G4s)是一种特殊的核酸高级结构,其在病毒基因组中的形成或解链可调节基因的复制、转录和翻译等过程,进而影响病毒增殖。一些可调节G-四链体结构稳定性的小分子呈现出抗病毒活性,使得G-四链体有望成为新的抗病毒药物的靶标。番茄丛矮病毒(tomato bushy stunt virus, TBSV)是一种分布广泛的植物病毒,有关其基因组的复制、转录和翻译等分子机制已研究得较为成熟,是一种研究病毒与寄主互作的模式病毒。揭示TBSV中G-四链体的结构及功能,有望为植物病毒基因中G-四链体的研究奠定基础。本研究通过生物信息学分析,在TBSV基因中鉴定出两条保守的、潜在的G-四链体可形成序列(putative G-quadruplex sequences, PQS)——TBSV-PQS2和TBSV-PQS4;通过紫外、荧光光谱和圆二色光谱(CD光谱)方法筛选出与TBSV-PQS2和TBSV-PQS4互作的G4配体;通过烟草体内侵染性克隆试验发现,G-四链体配体...     

植物病毒在媒介昆虫体内的垂直传播研究进展

对于多数植物病毒而言,其在田间的自然扩散主要依赖昆虫等介体生物,而媒介昆虫的垂直传播是植物病毒长期存在并发生的重要原因。对媒介昆虫垂直传播病毒机制的研究不仅可以为未来开发高效低毒农药奠定基础,更可为植物病毒与昆虫的互作和病毒病的预测预报提供新的视野及角度。媒介昆虫在植物病毒传播过程中的具体作用在近几年被广泛研究。该文综述了近年来植物病毒在昆虫体内垂直传播的研究进展,包括昆虫传播植物病毒的方式、植物病毒在昆虫体内的垂直传播方式以及虫媒病毒垂直传播的可能机制等。在整个垂直传播的过程中,植物病毒的衣壳蛋白、磷蛋白和媒介昆虫唐氏综合症细胞黏附分子、硫酸乙酰肝素糖蛋白、热激蛋白以及卵黄原蛋白,甚至共生菌都有参与。最后,基于媒介昆虫和植物病毒的关系对未来植物病毒病的绿色防控和生物防控进行了展望。     

Reservoirs of plant virus disease: Occurrence of wheat dwarf virus and barley/cereal yellow dwarf viruses in Sweden

Non-crop plants such as grasses and volunteer plants are an inseparable part of the flora of crop fields and can influence virus incidence in crop plants. The presence of grasses as virus reservoirs can lead to a higher probability of virus incidence in crop plants. However, the role of reservoirs as an inoculum source in agricultural fields has not been well studied for many viral diseases of crops. Grasses have been found to constitute potential reservoirs for cereal-infecting viruses in different parts of the world. This study revealed that cereal-infecting viruses such as wheat dwarf virus (WDV), barley yellow dwarf viruses (BYDVs), and cereal yellow dwarf virus-RPV (CYDV-RPV) can be found among ryegrass growing in or around winter wheat fields. Phylogenetic analysis showed that a WDV isolate from ryegrass was a typical WDV-E isolate that infects wheat. Similarly, a ryegrass isolate of barley yellow dwarf virus-PAV (BYDV-PAV) grouped in a clade together with other BYDV-PAV isolates. Inoculation experiments under greenhouse conditions confirmed that annual ryegrass of various genotypes can be infected with WDV to a very low titre. Moreover, leafhoppers were able to acquire WDV from infected ryegrass plants, despite the low titre, and transmit the virus to wheat, resulting in symptoms. Information from the grass reservoir may contribute to improving strategies for controlling plant virus outbreaks in the field. Knowledge of the likely levels of virus in potential reservoir plants can be used to inform decisions on insect vector control strategies and may help to prevent virus disease outbreaks in the future.     

新疆哈密瓜病毒类型及分布

 1981-1984年对新疆主要瓜产区的病毒发生情况进行了调查,可归纳为6个病毒类型。除1类型尚需进一步鉴定外,其他5类型分别属于黄瓜花叶病毒(CMV)、西瓜花叶病毒二号(WMV-2)、南瓜花叶病毒(SqMV)、烟草坏死病毒(TNV)和甜瓜叶脉坏死病毒(MVNV)。在大流行的1983年WMV-2和CMV,WMV-2和SqMV,CMV和SqMV以及WMV-2、SqMV和CMV的混合侵染率比1982年为高。各类型病毒的侵染率在不同地区也有较大的变化。     

An analysis of the durability of resistance to plant viruses

ABSTRACT Genetic resistance often fails because a resistance-breaking (RB) pathogen genotype increases in frequency. On the basis of an analysis of cellular plant pathogens, it was recently proposed that the evolutionary potential of a pathogen is a major determinant of the durability of resistance. We test this hypothesis for plant viruses, which differ substantially from cellular pathogens in the nature, size, and expression of their genomes. Our analysis was based on 29 plant virus species that provide a good representation of the genetic and biological diversity of plant viruses. These 29 viruses were involved in 35 pathosystems, and 50 resistance factors deployed against them were analyzed. Resistance was found to be durable more often than not, in contrast with resistance to cellular plant pathogens. In a third of the analyzed pathosystems RB strains have not been reported, and in another third RB strains have been reported but have not become prevalent in the virus population. The evolutionary potential of the viruses in the 35 pathosystems was evaluated with a compound risk index based on three evolutionary factors: the population of the pathogen, the degree of recombination, and the amount of gene and genotype flow. Our analysis indicates that evolutionary potential may be an important determinant of the durability of resistance against plant viruses.     

Synergy between grapevine vitiviruses and grapevine leafroll viruses

An interactive relationship between vitiviruses and grapevine leafroll viruses was characterized in grapevine. Grapevine viruses A and B (GVA and GVB) were found more frequently in the presence of co-infecting Grapevine leafroll associated viruses (GLRaV-1, ?2 or ?3) than in their absence. The titers of the vitiviruses in co-infection with leafroll viruses were found to be higher than were their titers in the absence of leafroll virus infection. The occurrence of vitivirus-associated stem-pitting symptoms was correlated with leafroll virus co-infection. Specific pairing associations on the species level were found between different viti- and leafroll virus species: GVB was associated preferentially with GLRaV-2; GVA was associated preferentially with GLRaV-1 and GLRaV-3. In contrast to the increase in vitivirus titer seen with leafroll virus co-infection, the incidence and titer of grapevine leafroll virus appeared to be unaltered by vitivirus co-infection. The potential for a synergistic enhancement of grapevine disease in co-infected vines is discussed.     

甘蔗病毒病及其防治研究进展

甘蔗是最重要的糖料作物,由于其栽培过程中采用种茎无性繁殖,病毒病发生逐年加重.已知侵染甘蔗的病毒种类有甘蔗花叶病毒(Sugarcane mosaic virus,SCMV)、高粱花叶病毒(Sorghummosaic virus,SrMV)、甘蔗线条花叶病毒(Sugarcane streakmosaic virus,SCSMV)、甘蔗黄叶病毒(Sugarcane yellow leaf virus,SCYLV)、甘蔗斐济病病毒(Sugarcane Fiji disease virus,SFDV)、甘蔗线.条病毒(Sugarcane streak virus,SSV)和甘蔗杆状病毒(Sugarcane bacilliform virus,SCBV).文中简要介绍上述几种病毒的基本特性及其所致病害的发生特点,对目前甘蔗病毒病防治技术进行了评述,提出了我国甘蔗病毒研究中需要关注的若干问题.     

利用小RNA高通量测序技术检测玉米病毒

正玉米是我国重要的粮食作物,种植范围日趋增大,病害的发生对玉米造成极大为害,病毒病对玉米稳产高产已构成严重威胁。近年来,安徽、山东和辽宁玉米主要种植区病毒病危害较重。为了检测发病玉米的病毒种类,本研究利用小RNA高通量测序技术鉴定玉米病毒,明确种类,以期为制定抗病毒策略提供理论依据。据不完全统计,世界上有40多种玉米病毒病(http://en.wikipedia.org),在我国发生并报道的有5种,分别为玉米粗缩病、玉米矮花叶病、玉米条纹矮缩病、玉米红叶病和玉     

Virus impact at the interface of an ancient ecosystem and a recent agroecosystem: studies on three legume-infecting potyviruses in the southwest Australian floristic region

The southwest Australian floristic region (SWAFR) is an internationally recognized 'hot spot' of global biodiversity and has an endangered flora. It represents a unique interface between an ancient ecosystem and a recent agroecosystem, providing the opportunity to investigate encounters where the recipient of the virus is an introduced crop and the donor a native plant and vice versa. Phylogenetic analysis of the virus coat-protein genes was used to study isolates of three potyviruses representing different 'new encounter' scenarios at this interface. The incidence, symptomatology, host range, non-persistent aphid transmission and considerable genetic diversity of the first indigenous virus described from the SWAFR, where it infects the native legume Hardenbergia comptoniana , and its potential to damage lupin, a locally important, newly introduced cultivated grain legume, was studied. The name Hardenbergia mosaic virus is proposed for this virus. Two other examples of 'new encounter' scenarios involving other legume-infecting potyviruses studied were: Passion fruit woodiness virus , which has been found only in Australasia, where it damages recently introduced species of Passiflora and legumes; and Bean yellow mosaic virus, which is not indigenous to Australia and was introduced recently to the SWAFR, where it infects a number of introduced legumes, but also damages the local native legume Kennedia prostrata . Isolates of the former had considerable genetic diversity consistent with the virus being indigenous, while isolates of the latter virus from K. prostrata had a low genetic diversity consistent with recent arrival. This research illustrates how introduced viruses can damage indigenous plants and indigenous viruses can damage introduced cultivated plants within this unique ecosystem, and how human activities can facilitate damaging 'new encounters' between plants and viruses.     

Novel cytopathological structures induced by mixed infection of unrelated plant viruses

ABSTRACT When two unrelated plant viruses infect a plant simultaneously, synergistic viral interactions often occur resulting in devastating diseases. This study was initiated to examine ultrastructural virus-virus interactions of mixed viral infections. Mixed infections were induced using potyviruses and viruses from other plant virus families. Novel ultrastructural paracrystalline arrays composed of co-infecting viruses, referred to as mixed virus particle aggregates (MVPAs), were noted in the majority of the mixed infections studied. When the flexuous rod-shaped potyvirus particles involved in MVPAs were sectioned transversely, specific geometrical patterns were noted within some doubly infected cells. Although similar geometrical patterns were associated with MVPAs of various virus combinations, unique characteristics within patterns were consistent in each mixed infection virus pair. Centrally located virus particles within some MVPAs appeared swollen (Southern bean mosaic virus mixed with Blackeye cowpea mosaic virus, Cucumber mosaic virus mixed with Blackeye cowpea mosaic virus, and Sunn hemp mosaic virus mixed with Soybean mosaic virus). This ultrastructural study complements molecular studies of mixed infections of plant viruses by adding the additional dimension of visualizing the interactions between the coinfecting viruses.