媒介昆虫与植物病毒互作研究进展

植物病毒大多借助媒介昆虫进行传播。植物病毒与媒介昆虫的互作关系研究是当今媒介生物学和生态学领域的前沿课题,也是寻找植物病毒有效防控途径的重要基础。本文主要概述了近十年来,包括呼肠孤病毒科Reoviridae、双生病毒科Geminiviridae、纤细病毒属Tenuivirus、番茄斑萎病毒属Tospovirus,、等多个科、属的植物病毒与其特异的媒介昆虫间的互作研究进展,探讨了昆虫传播植物病毒的机制以及昆虫对病毒入侵的响应机制,解析了植物病毒-媒介昆虫的互作关系,提出了未来研究发展的方向。     

植物病毒介体传播的分子机制

1前它植物病毒47个属中,被证实可通过天然生物媒介传播的病毒有40个属。植物病毒经空气传播（airborne）的介体是昆虫和螨,而经土壤传播（soil－borne）的介体为线虫和真菌。此外,植物病毒传播还可通过寄主植物的种子（seed－borne）和花粉（pllen－borne）传播。天然传播介体因其各自的生物学特性不同使其传播植物病毒的方式呈现不同的特点,且与被携带的病毒长期相互作用,形成特殊的传播机理。几十年来介体传播的机理和规律一直是植物病毒学研究的重要课题,并且已经积累了相当多的资料。然而,有关介体传播机理的分子水平的信息相对…     

病毒-植物互作对介体昆虫生物学特性的影响

大部分植物病毒需要介体来传播,而昆虫则是其最重要的介体类别。植物-病毒-介体昆虫的互作关系既复杂又特异,而病毒由于其繁殖迅速、变异快而成为三者协同进化的推动者,以有利于病毒的有效传播。病毒对介体昆虫的影响分直接影响和间接影响两个方面,间接影响即是病毒侵染寄主植物后会引起植物的光合作用、次生代谢、营养成分、信号途径等发生变化,继而影响介体昆虫的寄主选择行为、生长发育、繁殖力等生物学特性,最终会影响介体对于病毒的传播。综述了病毒侵染寄主植物对刺吸式昆虫生物学特性的影响,以期为防治植物病毒性病害提供依据。     

植物病毒介体传播的分子机制

1 前言 植物病毒47个属中,被证实可通过天然生物媒介传播的病毒有40个属.植物病毒经空气传播(air-borne)的介体是昆虫和螨,而经土壤传播(soil-borne)的介体为线虫和真菌.此外,植物病毒传播还可通过寄主植物的种子(seed-borne)和花粉(pollen-borne)传播.     

媒介昆虫-病毒-植物互作对生物入侵的影响

媒介昆虫-病毒-植物互作关系复杂多样。虽然相关的研究较多, 然而有关三者互作对于生物入侵的影响还知之甚少。已有证据表明, 寄主植物对病毒的敏感性和对媒介昆虫的适合性、媒介昆虫对寄主的适应能力等因素影响三者互作关系。当寄主植物易感病并且对媒介昆虫的适合性低, 而媒介昆虫对寄主植物的适应能力强时, 媒介昆虫与植物病毒之间很可能建立间接互惠关系, 这种互惠可促进媒介昆虫入侵和病毒病流行。此外, 媒介昆虫与植物病毒之间中性或偏害的互作关系对于外来生物入侵的促进作用也不容忽视。鉴于三者互作对于生物入侵的重要性, 今后需要对不同物种所组成的多种组合进行比较研究, 并采用多种方法揭示互作的生理和分子机制。     

植物病毒昆虫介体传播的研究进展

本文综述了目前非循回型植物病毒和循回型植物病毒昆虫介体传播机理的研究现状。     

马铃薯Y病毒属病毒与寄主互作的分子基础

近年来,分子生物学及生物技术的迅速发展,极大地促进了人们对马铃薯Y病毒属病毒与寄生之间,病毒与传播介体之间互作关系的研究,并取得了一些新的进展,从病毒诱导的症状,病毒的系统侵染,传播以及寄主植物抗病性等方面,对病毒与寄主互作关系的分子基础作一简述。     

马铃薯Y病毒属病毒与寄主互作的分子基础*

近年来 ,分子生物学及生物技术的迅速发展 ,极大地促进了人们对马铃薯Y病毒属病毒与寄主之间 ,病毒与传播介体之间互作关系的研究 ,并取得了一些新的进展。从病毒诱导的症状 ,病毒的系统侵染、传播以及寄主植物抗病性等方面 ,对病毒与寄主互作关系的分子基础作一简述。     

昆虫介体行为与植物病毒的传播

大多数植物病毒都是依赖昆虫介体进行传播,其中超过80%的传毒介体昆虫都是属于半翅目同翅亚目。昆虫介体识别寄主植物和取食的过程与病毒的传播密切相关,本文主要综述了同翅亚目昆虫、蓟马等介体昆虫取食行为与植物病毒的相互作用方面的研究进展,着重于介绍昆虫不同取食阶段的行为对植物病毒传播的影响,病毒侵染对介体取食和识别寄主行为的影响。     

植物病毒昆虫介体传播的研究进展

本文综述了目前非循回型植物病素和循回型植物病毒昆虫介体传播机理的研究现状 。     

Novel strategies targeting pathogen transmission reduction in insect vectors: Tsetse-transmitted trypanosomiasis control

Insect vectors are essential for the transmission of important human diseases such as malaria, leishmaniasis, Chagas and sleeping sickness. Insects are also responsible for the transmission of agricultural diseases that affect livestock and crops. Traditionally, control of the vector populations has been an effective disease management strategy. Recently, vector control strategies have been fortified by research in insect biology and in insect–pathogen interactions as well as by the development of transgenic technologies. In addition to insect population reduction methods, disease control via selective elimination of pathogens in insects can now be explored. Here we explore the tsetse vectors of African trypanosomes and describe the application of recent knowledge gained in their symbiotic, reproductive and vectorial biology to develop novel disease control strategies.     

Outcomes of co-infection by two potyviruses: implications for the evolution of manipulative strategies

Recent studies have documented effects of plant viruses on host plants that appear to enhance transmission by insect vectors. But, almost no empirical work has explored the implications of such apparent manipulation for interactions among co-infecting pathogens. We examined single and mixed infections of two potyviruses, watermelon mosaic virus (WMV) and zucchini yellow mosaic virus (ZYMV), that frequently co-occur in cucurbitaceae populations and share the same aphid vectors. We found that ZYMV isolates replicated at similar rates in single and mixed infections, whereas WMV strains accumulated to significantly lower levels in the presence of ZYMV. Furthermore, ZYMV induced changes in leaf colour and volatile emissions that enhanced aphid (Aphis gossypii) recruitment to infected plants. By contrast, WMV did not elicit strong effects on plant–aphid interactions. Nevertheless, WMV was still readily transmitted from mixed infections, despite fairing poorly in in-plant competition. These findings suggest that pathogen effects on host–vector interactions may well influence competition among co-infecting pathogens. For example, if non-manipulative pathogens benefit from the increased vector traffic elicited by manipulative competitors, their costs of competition may be mitigated to some extent. Conversely, the benefits of manipulation may be limited by free-rider effects in systems where there is strong competition among pathogens for host resources and/or access to vectors.     

Plant infection by two different viruses induce contrasting changes of vectors fitness and behavior

Insect-vectored plant viruses can induce changes in plant phenotypes,thus influencing plant-vector interactions in a way that may promote their dispersal according to their mode of transmission (i.e.,circulative vs.noncirculative).This indirect vector manipulation requires host-virus-vector coevolution and would thus be effective solely in very specific plant-virus-vector species associations.Some studies suggest this manipulation may depend on multiple factors relative to various intrinsic characteristics of vectors such as transmission efficiency.In anintegrative study,we tested the effects of infection of the Brassicaceae Camelina sativa with the noncirculative Cauliflower mosaic virus (CaMV)or the circulative Turnip yellows virus (TuYV)on the host-plant colonization of two aphid species differing in their virus transmission efficiency:the polyphagous Myzus persicae,efficient vector of both viruses,and the Brassicaceae specialist Brevicoryne brassicae,poor vector of TuYV and efficient vector of CaMV.Results confirmed the important role of virus mode of transmission as plant-mediated effects of CaMV on the two aphid species induced negative alterations of feeding behavior (i.e.,decreased phloem sap ingestion)and performance that were both conducive for virus fitness by promoting dispersion after a rapid acquisition.In addition,virus transmission efficiency may also play a role in vector manipulation by viruses as only the responses of the efficient vector to plant-mediated effects of TuYV,that is,enhanced feeding behavior and performances,were favorable to their acquisition and further dispersal.Altogether,this work demonstrated that vector transmission efficiency also has to be considered when studying the mechanisms underlying vector manipulation by viruses.Our results also re- inforce the idea that vector manipulation requires coevolution between plant,virus and vector.     

Begomovirus-whitefly mutualism is achieved through repression of plant defences by a virus pathogenicity factor

Plant-mediated interactions between herbivorous arthropods and pathogens transmitted by herbivores are important determinants of the population dynamics of both types of organisms in the field. The role of plant defence in mediating these types of tripartite interactions have been recognized but rarely examined especially at the physiological and molecular levels. Our previous work shows that a worldwide invasive whitefly can establish mutualism with the begomovirus Tomato yellow leaf curl China virus (TYLCCNV) via crop plants. Here, we show that TYLCCNV and betasatellite co-infection suppresses jasmonic acid defences in the plant. Impairing or enhancing defences mediated by jasmonic acid in the plant enhances or depresses the performance of the whitefly. We further demonstrate that the pathogenicity factor βC1 encoded in the betasatellite is responsible for the initiation of suppression on plant defences and contributes to the realization of the virus-vector mutualism. By integrating ecological, mechanistic and molecular approaches, our study reveals a major mechanism of the plant-mediated mutualism between a virus and its vector. As the test plant is an important economic crop, the results also have substantial implications for developing novel strategies for management of crop viruses and the insect vectors associated with them.     

Patterns of virulence and benevolence in insect‐borne pathogens of plants

Direct and indirect interactions between insect‐borne pathogens and their host plants are reviewed in the context of theoretical analyses of the evolution of virulence. Unlike earlier theories, which maintained that parasites should evolve to be harmless or even beneficial to their hosts, recent models predict that coevolution between pathogen and host may lead to virulence or avirulence, depending on the pathogen transmission system. The studies reviewed here support the hypothesis that virulence can be advantageous for insect‐borne pathogens of plants. Virulent pathogens may be transmitted more readily by vector insects and are likely to induce stronger disease symptoms, thereby potentially making the plant more attractive to vectors. In contrast, the transmission advantage of virulence for seed‐transmitted pathogens is lower and the costs of virulence are high. Pathogens may sometimes benefit plants via indirect interactions that arise through relationships with other organisms. Evidence for the effects of insect‐borne pathogens on plant competition, herbivory, and parasitism also is reviewed, but few studies have measured the outcome of both direct and indirect interactions. Benefits of pathogen infection that accrue to plants from indirect interactions may sometimes outweigh the direct detrimental effects of virulence.     

植物病毒病媒介昆虫的传毒特性和机制研究进展

植物病毒病是农作物的“癌症”, 至今缺少有效的防治方法。目前已知80%的植物病毒病依赖于媒介昆虫传播, 而媒介昆虫对植物病毒的传播是一个昆虫、 病毒、 寄主植物互作的过程, 历经获毒、 持毒和传毒等多个阶段, 昆虫体内一系列病毒受体或蛋白参与了这个过程。昆虫传播病毒的方式有口针携带式、 前肠保留式和体内循环式3类, 它们各自对应的持久性为非持久性、 半持久性和持久性, 不同昆虫获取这3类病毒的获毒时间、 在体内存留位置和传毒时间也各不相同。 这个过程受到媒介昆虫的性别及龄期、 寄主植物、 环境条件、 昆虫体内共生菌等多种因素的影响。与之相关的蛋白主要有病毒衣壳蛋白(CP)、 次要衣壳蛋白（CPm）、 GroEL蛋白、 辅助因子(HC)和下颚口针蛋白等。近年来对植物病毒基因组的研究也取得了很大的进展, 对昆虫传毒机制的研究正受到越来越广泛的关注。本文综述了近年来该领域内的相关研究进展, 包括昆虫传播植物病毒的传毒方式、 影响传毒效率的因素、 传毒机制特别是昆虫体内与病毒传播可能相关的受体等。     

Arranging the bouquet of disease: floral traits and the transmission of plant and animal pathogens

Several floral microbes are known to be pathogenic to plants or floral visitors such as pollinators. Despite the ecological and economic importance of pathogens deposited in flowers, we often lack a basic understanding of how floral traits influence disease transmission. Here, we provide the first systematic review regarding how floral traits attract vectors (for plant pathogens) or hosts (for animal pathogens), mediate disease establishment and evolve under complex interactions with plant mutualists that can be vectors for microbial antagonists. Attraction of floral visitors is influenced by numerous phenological, morphological and chemical traits, and several plant pathogens manipulate floral traits to attract vectors. There is rapidly growing interest in how floral secondary compounds and antimicrobial enzymes influence disease establishment in plant hosts. Similarly, new research suggests that consumption of floral secondary compounds can reduce pathogen loads in animal pollinators. Given recent concerns about pollinator declines caused in part by pathogens, the role of floral traits in mediating pathogen transmission is a key area for further research. We conclude by discussing important implications of floral transmission of pathogens for agriculture, conservation and human health, suggesting promising avenues for future research in both basic and applied biology.