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。     

miRNA调控昆虫与病毒互作的研究进展

miRNA是一类重要的非编码小分子RNA,可在转录后水平调控基因表达,参与并调控机体的生长发育、细胞分化、细胞凋亡、抗病毒、激素分泌、神经系统等重要生物过程。本文介绍了miRNA的合成途径及其生物学功能,并重点阐述miRNA在昆虫宿主与病毒互作中的调控作用:通过mRNA剪切或抑制靶标蛋白的翻译负调控靶标基因,实现基因沉默,调控约50%的蛋白质编码基因的表达,许多miRNA已被发现在人体和植物中参与调控病毒的复制侵染,因此也有可能控制害虫对病毒抗性的产生,恢复病毒对害虫的防控作用。最近有研究将害虫特异的miRNA转入植物,干扰昆虫蜕皮过程导致幼虫的死亡,作为Bt转基因作物的替代,成为抗虫基因工程的新选择。研究miRNA在昆虫对病毒抗性产生中的作用,将为昆虫抗病毒机制的研究提供新的思路,为害虫生物防治措施的应用及改进提供理论参考。     

植物与植食性昆虫的分子互作:基础与应用

植物与植食性昆虫之间存在着复杂的分子互作.首先,植食性昆虫会利用自身的嗅觉和味觉化学感觉系统,通过对植物挥发性和非挥发性信息化合物的编码与解析,结合对植物颜色、形状等物理信息的感觉与编码,定位及确定寄主植物.其次,植物可以通过位于细胞膜的受体识别植食性昆虫相关模式分子和损伤相关模式分子,启动由早期信号事件和植物激素信号...     

植物病毒载体在植病互作研究中的应用

在植物与病原菌互作的研究中,植物抗性基因和病原菌无毒基因的研究是两个重要的热点。利用植物病毒沉默载体构建的VIGS(Virus Induced Gene Silencing)体系研究植物的防御机制;利用植物病毒表达载体克隆和研究病原菌的无毒基因,将使我们更深刻地理解植物和病原菌互作的分子机理,最终为培育番茄白粉病持久抗性品种打下理论基础。对植物病毒载体的研究进行了综述并就我们承担的课题进行了讨论。     

气候变化对植物-传粉昆虫的分布区和物候及其互作关系的影响

全球气候变化对生态系统的影响是人类社会面临的紧迫而又严峻的挑战。气候变化带来的极端气候事件的增多, 直接影响到生态系统生产力和服务功能。本文总结了气候变化对植物-传粉昆虫互作的研究进展, 强调植物-传粉昆虫互作网络结构和其时空演变的解析, 以及互作关系和功能性状重组研究的重要性。近年来在气温持续上升背景下对植物-传粉昆虫互作关系影响的研究也受到了更多关注, 这些研究主要集中在两方面: 一是植物和传粉昆虫分布区的变化, 包括部分种群可能灭绝; 二是物候的变化, 即植物花期和传粉昆虫活动期的改变。植物与传粉昆虫任何一方在空间或时间上的改变, 都会导致传粉关系的错配或丢失。此外, 也可能导致植物-传粉昆虫双方的功能性状及其耦合的改变, 从而影响其互作关系的稳定。建议在今后的研究中关注: (1)覆盖生物多样性的多个尺度的研究; (2)对植物-传粉者互作网络的长期监测; (3)重要指示物种繁殖适合度评价; (4)植物-传粉昆虫互作双方功能性状在时间和空间尺度上的变化, 及其互作关系的重组; (5)关键植物和传粉昆虫类群的评估和保护。     

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。     

植物与病原真菌互作机制研究进展

植物与病原真菌之间的互作是当今植物病理学研究的热点问题之一,相关的研究有望为植物抗病机制的解析和抗病品种的选育奠定理论基础。我们从形态、细胞、生理生化和分子等水平综述了植物与病原真菌互作机制的研究进展。     

R-Avr基因互作介导的植物抗病性

Ｒ－Ａｖｒ基因互作介导的植物抗病性李汝刚范云六伍宁丰李茂林（中国农业科学院生物技术研究中心,北京１０００８１）植物在整个生长发育周期中面临着种类繁多的病原微生物袭击,但真正能引起植物病害的病原并不多,这表明植物能抵抗大多数病原微生物袭击,表现非亲合性...     

生物入侵对鸟类的生态影响

生物入侵是全球生物多样性面临的最主要威胁之一, 入侵种在改变入侵地环境的同时也使当地的生物受到极大影响。鸟类在生态系统中处于较高的营养级, 生态系统中任何一个环节的变化都可能对鸟类造成一定的影响。本文回顾了哺乳动物、鸟类、无脊椎动物和植物等不同生物类群的入侵对本地鸟类生态影响方面的研究进展。外来生物对鸟类的影响主要表现在以下几方面: (1)外来哺乳动物对成鸟、幼鸟或鸟卵的捕食作用; (2)外来鸟类与本地鸟类竞争栖息地和食物资源, 与当地的近缘种杂交而造成基因流失; (3)外来无脊椎动物改变本地鸟类的栖息环境和食物状况, 甚至直接捕食本地鸟类; (4)外来植物入侵改变入侵地的植物群落组成和结构, 造成本地鸟类的栖息地丧失或破碎化, 并通过改变入侵地生态系统的食物链结构而对高营养级的鸟类产生影响。最后, 作者还提出了该领域有待解决的问题和今后可能的研究方向。     

Effects of biological invasions on forest carbon sequestration

There has been a rapidly developing literature on the effects of some of the major drivers of global change on carbon (C) sequestration, particularly carbon dioxide (CO₂) enrichment, land use change, nitrogen (N) deposition and climate change. However, remarkably little attention has been given to one major global change driver, namely biological invasions. This is despite growing evidence that invasive species can dramatically alter a range of aboveground and belowground ecosystem processes, including those that affect C sequestration. In this review, we assess the evidence for the impacts of biological invaders on forest C stocks and C sequestration by biological invaders. We first present case studies that highlight a range of invader impacts on C sequestration in forest ecosystems, and draw on examples that involve invasive primary producers, decomposers, herbivores, plant pathogens, mutualists and predators. We then develop a conceptual framework for assessing the effects of invasive species on C sequestration impacts more generally, by identifying the features of biological invaders and invaded ecosystems that are thought to most strongly regulate C in forests. Finally we assess the implications of managing invasive species on C sequestration. An important principle that emerges from this review is that the direct effects of invaders on forest C are often smaller and shorter‐term than their indirect effects caused by altered nutrient availability, primary productivity or species composition, all of which regulate long‐term C pools and fluxes. This review provides a conceptual basis for improving our general understanding of biological invaders on ecosystem C, but also points to a paucity of primary data that are needed to determine the quantitative effects of invaders on ecosystem processes that drive C sequestration.     

生物入侵机制研究进展

本文从外来种本身的生物学特性,外来种与新栖息地土著种之间的相互作用,群落生物多样性对入侵种的抵抗能力,新栖息地生态环境变化对入侵种的影响等方面综述了近年来有关生物入侵机制的研究进展,并探讨了研究方法的发展和亟待解决的问题,大量的研究表明生物入侵机制是极为多样的,可能没有一般的,通用的机制,阐明生物入侵的机制,对推动生态学理论的发展和控制有害外来种有重要意义。     

Climate warming affects biological invasions by shifting interactions of plants and herbivores

Plants and herbivorous insects can each be dramatically affected by temperature. Climate warming may impact plant invasion success directly but also indirectly through changes in their natural enemies. To date, however, there are no tests of how climate warming shifts the interactions among invasive plants and their natural enemies to affect invasion success. Field surveys covering the full latitudinal range of invasive Alternanthera philoxeroides in China showed that a beetle introduced for biocontrol was rare or absent at higher latitudes. In contrast, plant cover and mass increased with latitude. In a 2‐year field experiment near the northern limit of beetle distribution, we found the beetle sustained populations across years under elevated temperature, dramatically decreasing A. philoxeroides growth, but it failed to overwinter in ambient temperature. Together, these results suggest that warming will allow the natural enemy to expand its range, potentially benefiting biocontrol in regions that are currently too cold for the natural enemy. However, the invader may also expand its range further north in response to warming. In such cases where plants tolerate cold better than their natural enemies, the geographical gap between plant and herbivorous insect ranges may not disappear but will shift to higher latitudes, leading to a new zone of enemy release. Therefore, warming will not only affect plant invasions directly but also drive either enemy release or increase that will result in contrasting effects on invasive plants. The findings are also critical for future management of invasive species under climate change.     

超富集植物吸收富集重金属的生理和分子生物学机制

与普通植物相比,超富集植物在地上部富集大量重金属离子的情况下可以正常生长,其富集重金属的机理已经成为当前植物逆境生理研究的热点领域．尤其是近两年,随着分子生物学等现代技术手段的引人,关于重金属离子富集机理的研究取得了一定进展．通过与酵母突变株功能互补克隆到了多条编码微量元素转运蛋白的全长cDNA;也从分子水平上研究了谷胱甘肽、植物螯合素、金属硫蛋白、有机酸或氨基酸等含巯基物质与重金属富集之间的可能关系．本文从植物生理和分子生物学角度简要评述超富集植物对重金属元素的吸收、富集、整合及区室化的机制．     

Relative importance of biological and human-associated factors for alien plant invasions in Hokkaido,Japan

AimsThe invasion success of alien plants is strongly affected by both biological and human-associated factors. Evaluation of the relative contribution of each factor is important not only for the further understanding of invasion processes but also for the better management of invasion risk, particularly in protected areas of high conservation priority. Here, we quantified the relative importance of species biological traits and association with a human activity, i.e. agriculture, in explaining the invasion success of alien plants across the entire region and in protected areas in Hokkaido, Japan.     

Evidence for non-uniform dispersal in the biological invasions of two naturalized North American bird species

Most previous attempts to model the geographical range expansion of an invading species assume random dispersal of organisms through a homogeneous environment. These models result in a series of uniformly increasing circles radiating out from the centre of origin over time. Although these models often give reasonable fits to available data, they do not typically include mechanisms of dispersal. Alternatively, models that include assumptions of non‐random dispersal and a heterogeneous environment inevitably result in an anisotropic or jagged invasion front. This front will include propagules of pioneer individuals for the expanding species. Existing data from biological invasions reveal that the spatial structure of an invading species usually exhibits these propagules. Using population data gathered from the past century, we investigated the propagules of two North American invading bird species: the European starling (Sturnus vulgaris Linnaeus), and the house finch (Carpodacus mexicanus Müller), and found a correlation between propagule location and habitat quality. These results suggest that dispersing individuals seek out favourable habitat and remain there, thus introducing a possible mechanism for explaining non‐uniform dispersal during invasions. When combined with results from other studies, our results suggest that propagules provide starting points for future population expansion of an invading species.     

双功能乙醛/乙醇脱氢酶AdhE参与细菌与宿主互作的机制研究进展

双功能乙醛/乙醇脱氢酶AdhE具有乙醛脱氢酶和乙醇脱氢酶的催化活性,是细菌乙醇厌氧发酵途径中的关键酶之一。近年,有关细菌与宿主相互作用的研究表明,AdhE在细菌适应宿主内环境变化和发挥毒力时具有重要的调控作用。本文对AdhE参与调控细菌感染宿主的致病机制和参与细菌对宿主免疫功能调节的作用机制进行综述,以期为AdhE的功能研究提供新的思路。     

Electrodynamics of interactions in electrolyte media. Possible consequences in biological functions

Attention is drawn to the fact that electric charge interactions in aqueous electrolyte solutions, such as physiological media, depend not only on the distance between the interacting charges but also on the frequency at which they move. This fact has important consequences for some biological processes, particularly the kinetic ones. Consideration of charge screening, including the dynamic effects, shows that electrical interactions in quasi-physiological systems are effective even above Debye’s length, provided that charges move at frequencies higher than ～250 MHz. For each electrolyte solution, it is possible to define a threshold frequency, the Maxwell frequency, as the point of crossover between a conducting and a dielectric regime in the solution.