3种植物对椰心叶甲及椰心叶甲啮小蜂选择行为的影响

[目的]阐明3种植物的挥发物对椰心叶甲及椰心叶甲啮小蜂的引诱作用。[方法]利用四臂嗅觉仪在室内测试了椰子、大王棕和槟榔3种植物的挥发物对椰心叶甲雌成虫选择行为的影响,同时采用Y型嗅觉仪测试椰心叶甲啮小蜂对这3种植物受害前后挥发物的行为反应。[结果]3种植物的老叶和心叶的挥发物对椰心叶甲具有显著的引诱作用,对椰心叶甲啮小蜂无引诱作用,但当3种植物的心叶在遭受椰心叶甲幼虫为害后及为害后的去虫叶,其挥发物对椰心叶甲啮小蜂具有显著的引诱作用;3种植物受幼虫为害的心叶的挥发物之间对椰心叶甲啮小蜂的引诱作用均无显著差异。[结论]在椰心叶甲幼虫为害寄主植物心叶后可引诱椰心叶甲啮小蜂主动搜索和识别寄主。     

具信号功能的植物挥发物研究进展

植物释放的挥发物是植物次生代谢产物,可由各种植物组织生产。植物是挥发性物质生产和释放的主体,虫害叶片众多挥发物的可控释放有助于植物阻止植食昆虫或者吸引它们的天敌,在植物—害虫—天敌三级营养关系中起着信号物质的作用。文章综合近年来国内外的研究进展,对具有信号功能的挥发物的种类、激发子、合成途径及其化学生态功能作一概述。     

虫害诱导植物挥发物的释放机制及应用

虫害诱导的植物挥发物(HIVs)是植物受到害虫为害时产生和释放的,并且是植物进行通讯和保护自身的挥发性物质.HIVs能调节植物、植食性昆虫和天敌之间的关系,对昆虫的行为调控有非常重要的作用,近年来已引起人们的广泛关注.从HIVs的释放机制和应用两方面进行综述,有助于开发和利用HIVs保护植物,降低植食性害虫的危害水平,实施保护植物的新策略.     

Genetic engineering of terpenoid metabolism attracts bodyguards to Arabidopsis

Herbivore-damaged plants release complex mixtures of volatiles that attract natural enemies of the herbivore. To study the relevance of individual components of these mixtures for predator attraction, we manipulated herbivory-induced volatiles through genetic engineering. Metabolic engineering of terpenoids, which dominate the composition of many induced plant volatile bouquets, holds particular promise. By switching the subcellular localization of the introduced sesquiterpene synthase to the mitochondria, we obtained transgenic Arabidopsis thaliana plants emitting two new isoprenoids. These altered plants attracted carnivorous predatory mites (Phytoseiulus persimilis) that aid the plants' defense mechanisms.     

Defensive function of herbivore-induced plant volatile emissions in nature

Herbivore attack is known to increase the emission of volatiles, which attract predators to herbivore-damaged plants in the laboratory and agricultural systems. We quantified volatile emissions from Nicotiana attenuata plants growing in natural populations during attack by three species of leaf-feeding herbivores and mimicked the release of five commonly emitted volatiles individually. Three compounds (cis-3-hexen-1-ol, linalool, and cis-alpha-bergamotene) increased egg predation rates by a generalist predator; linalool and the complete blend decreased lepidopteran oviposition rates. As a consequence, a plant could reduce the number of herbivores by more than 90% by releasing volatiles. These results confirm that indirect defenses can operate in nature.     

Cell walls of crown-gall tumors and embryonic plant tissues lack agrobacterium adherence sites

Crown-gall tumor initiation by Agrobacterium tumefaciens is inhibited by cell walls from normal dicotyledonous plants but not by cell walls from crown-gall tumors apparently because of bacterial adherence or nonadherence, respectively, to the different cell walls. Cell walls from normal and tumor tissues in culture also show this difference, indicating that the two types of tissue stably maintain this difference under these conditions. Habituated tissue cultures, which resemble crown-gall tumor cultures, however, form cell walls that are inhibitory like those of the normal cultures from which they are derived. Monocotyledonous plants do not act as hosts for Agrobacterium and bacteria-specific inhibition is not shown by cell walls from several species of grass, a monocot family. Cell wallsfrom "embryonic" tissues (dicot seedlings less than 2 centimeters long), unlike those from older seedlings, are non-inhibitory. Crown-gall tumors thus resemble embryonic tissues in this respect.     

落叶松单萜类挥发物微胶囊缓释剂对落叶松毛虫寄主选择行为的影响

单萜类植物挥发物挥发性较强,能够影响昆虫的行为。为了延长其作用时间,本研究选取落叶松单萜类挥发 物-蒎烯、月桂烯和莰烯,将其制成微胶囊悬浮剂喷施2 年生兴安落叶松树苗,同时直接用3 种挥发物喷施落叶松 苗,进行对比。在处理后的5 d 内,通过室内Y 形管嗅觉仪和室外笼罩试验,分别测定各处理落叶松苗对落叶松毛 虫雌成虫寄主选择行为的影响。结果显示:-蒎烯1 L/mL 和月桂烯1 L/mL, 对雌虫有显著引诱作用(P 0.01); 两者的微胶囊缓释剂有明显的引诱作用,效果可持续4 d;莰烯2 L/mL 有显著驱避作用(P 0.01);其微胶囊缓释 剂有明显的驱避作用,效果可持续4 d;在施用-蒎烯或月桂烯的各树苗上,雌虫产卵量显著高于对照,效果可持续 3 d;莰烯的各处理树苗上,落叶松毛虫雌虫产卵量显著低于对照,效果可持续3 d。这表明单萜类挥发物的微胶囊 悬浮剂与挥发物具有相同的作用效果,并可以有效延长挥发物的作用时间。      

4种罗勒叶片挥发物比较分析

【目的】研究不同罗勒叶片自然释放出的挥发物成分及释放量,确定其主要成分。【方法】采用动态顶空法采集丁香罗勒(Ocimum gratissimum)、罗勒(O.basilicum)、紫罗勒(O.basilicum‘Purple Ruffles’)和绿罗勒(O.basilicum‘Green’)4种罗勒释放的挥发物,利用自动热脱附-气相色谱/质量色谱联用技术对挥发物成分和释放量进行分析。【结果】4种罗勒共释放出49种成分,分别属于萜烯类、醇类、醛类、酮类、烷烃类、酯类、苯形烃及其衍生物,不同种罗勒挥发物成分的种类和释放量间存在明显的差异。在丁香罗勒、罗勒、紫罗勒和绿罗勒的叶片挥发物中分别检测出30、28、31和25种物质。萜烯类化合物的释放量在4种罗勒中均为最高,分别占总释放量的41.7%(丁香罗勒)、40.4%(罗勒)、46.6%(紫罗勒)和34.4%(绿罗勒)。【结论】桉叶油醇在4种罗勒中均表现出最高的释放量,可初步判断其是罗勒植物的主要香气成分。     

松墨天牛对雪松挥发物的触角电位和嗅觉反应

用改进的水蒸气蒸馏法提取健康雪松枝条精油,结合气相色谱—质谱(GC-MS)联用仪进行定量和定性分析,共鉴定出20种化合物,主要为萜烯类化合物。利用嗅觉仪和触角电位(EAG)仪比较分析了松墨天牛成虫对健康雪松枝条挥发物的嗅觉反应和触角电位反应,及其对健康木挥发物的日龄变化规律。结果表明,交配前雄虫对挥发物的敏感性较雌虫强,15日龄前雌、雄虫的EAG反应值随日龄的增加而升高,未交配天牛对健康木挥发物表现为正趋性,已交配天牛则表现为负趋性;雌虫12日龄和雄虫9日龄正趋性最强,说明不同日龄的松墨天牛成虫对雪松挥发物具有不同的敏感性和选择性。雌、雄天牛之间在EAG和嗅觉反应方面无明显差异,两者对寄主挥发物的行为感受机制相同。     

乙烯与（Z）ˉ3ˉ己烯醛对合作杨挥发物产生的影响

采用熏蒸的方法,研究了乙烯、（Z）ˉ3ˉ己烯醛、乙烯混合（Z）ˉ3ˉ己烯醛 和茉莉酸甲酯等几种 处理,对合作杨萜烯类挥发物和绿叶性气体释放的影响。结果表明,单独的乙烯处理对 合作杨挥发 物产生不具诱导能力;与单独用（Z）ˉ3ˉ己烯醛处理相比较,乙烯与（Z）ˉ3ˉ己烯醛 的混合处理对己醛 和1ˉ己烯ˉ3ˉ醇的释放存在显著促进作用,说明乙烯在与（Z）ˉ3ˉ己烯醛在调节合 作杨植株间伤害信 息产生上具有协同作用。     

Methylcyclopentanoid monoterpenes mediate interactions among insect herbivores

Beetles secrete an array of chemicals generally believed to mitigate attack by predators. Methylcyclopentanoid monoterpenes secreted by larvae of the willow leaf beetle, Plagiodera versicolora, deter feeding by conspecific adults. Furthermore, the secretion elicits a strong repugnancy response in larvae of another willow herbivore, Nymphalis antiopa. Leaves bearing beetle larvae are less likely than leaves not bearing beetles to be frequented and consumed by Nymphalis larvae. Predator defense may not be the sole function of glandular secretions produced by herbivorous insects; secretions may also mediate interactions among herbivores that use a common resource.     

植物挥发物介导的种内与种间关系研究进展

植物通过释放的挥发性有机化合物(Volatile organic compounds,VOCs)介导其与周围环境中同种和不同种生物的相互作用,从吸引传粉、种子传播媒介,到保护自己免受植食性动物、病原菌和寄生生物的侵害等。植物挥发物尤其是虫害诱导挥发物是近30年来化学生态学和植物保护领域的研究热点。本文综述了近年来植物挥发物介导的种内与种间关系的研究进展,主要概括了植物挥发物的基本特征,植物挥发物在调控植物种内及种间、植物与昆虫、植物–害虫–天敌三营养级关系、以及植物与微生物互作中的生态学功能,并对其在农业生产中的应用和前景进行分析,总结这一领域尚未解决和亟需深入研究的问题,为植物挥发物应用于有害生物的控制提供理论依据。     

Response of Cytochrome P450 Expression to Maize Volatiles in Helicoverpa armigera (Hübner)

The 7-ethoxycoumarin O-deethylase (ECOD) activities of cytochrome P450s and differential expression of six cytochrome P450 genes induced by the volatiles from both damaged and undamaged maize plants were investigated in the cotton bollworm, Helicoverpa armigera (Hübner). The ECOD activity changed with time of exposure to maize volatiles. At 36 h after cotton bollworm larvae exposure to maize volatiles, the ECOD activities in cotton bollworm damaged and artificially damaged groups were 2.36 and 4.53 times higher than the control group respectively. The relative expression levels of CYP4S1, CYP6B2 and CYP6B7 in the cotton bollworm were significantly increased in artificially damaged plant group, which was 2.93, 5.09 and 10.66 times higher than that in the control group, respectively. The expression levels of CYP6B2, CYP6B6, CYP9A12, and CYP9A14 were much lower in the larvae exposure to volatiles from both healthy and pest damaged maize seedlings than in the control group at 12 h after larvae exposure to maize volatiles. For the cotton bollworm damaged maize group, the expression of CYP4S1 and CYP9A14 increased.     

植食性昆虫诱导的挥发物及其 在害虫防治中的作用

植物受到植食性昆虫为害后、会通过间接防御途径产生和释放一种挥发性气体（HIPVs）、HIPVs 对植食 性昆虫及其天敌具有重要的调控作用、对于害虫可以起到有效防治作用。HIPVs 的释放机制主要分为JA 和SA 两种 信号途径、不同植食性昆虫会诱导不同信号途径的激活。主要从种植抗虫栽培品系尧应用转基因植物尧人工释放合成 的HIPVs尧利用外源性化学物质等方面综述了利用HIPVs 进行生物防治的现状、可为进一步开发利用HIPVs 进行农 业防治提供一定理论基础。     

我国主要松树诱导抗虫性的一些规律比较

该文以马尾松、油松、华北落叶松3种我国主要针叶树为对象,分析比较了3种松树在受松毛虫危害后,所产生的迅速诱导抗性和滞后诱导抗性;研究了取食相应的受害针叶后,其生长发育情况的变化;探讨了松树诱导抗性对松毛虫种群动态的作用过程,总结了我国主要松树诱导抗性的一般规律,为分析松毛虫发生机理及松毛虫综合管理提供理论依据.     

植物挥发物及寄生经历在半闭弯尾姬蜂寄主搜索行为中的作用

研究了不同处理甘蓝植株释放的挥发物及寄生经历在半闭弯尾姬蜂寄主搜索行为中的作用.与完整植株相比,机械损伤植株、虫损伤植株、虫-植株复合体释放的挥发物对半闭弯尾姬蜂的引诱力显著提高,且以虫-植株复合体释放的挥发物引诱力相对最强,表明植物受虫害后的挥发物对该蜂的寄主搜索起着重要的诱导作用,寄主幼虫的挥发物也起一定作用.雌蜂在虫损伤植株、小菜蛾-植株复合体上所停留的时间较在完整植株和机械损伤植株上显著要长.寄生经历能够明显增强半闭弯尾姬蜂搜索寄主的效率.     

绿叶挥发物代谢调控及分子机理研究进展

植物处于复杂的自然环境中,常受到植食性昆虫、病原菌及机械损伤等生物或非生物的侵害并造成植物的局部伤害,从而启动复杂的防御反应。释放绿叶挥发物（green leaf volatiles,GLVs）是植物防御性反应之一。绿叶挥发物是植物不饱和脂肪酸经过Oxylinpins生化途径中的脂氧合酶（LOX ）和脂氢过氧化物裂解酶（HPL）催化而形成的一类C6和C9醛、醇及其相应的酯类。作为启动植物防御机制的信号分子,这类挥发性物质通过长距离的气态传输在植物与病原菌、植物与植食性昆虫、植物自身和相邻的植物之间起作用,从而介导防御性反应。研究其生化途径及其调节机理,对探索其对病虫害的直接、间接防御、改善作物风味品质及抗病新种质创制起着非常重要的作用,且对园艺植物甚至农林生态系统中作物病虫害综合治理策略的制定具有重要的指导意义。该文综述了绿叶挥发物合成的生化途径及其作为信号转导物质的作用机制,并阐述了绿叶挥发物在植物抗逆方面的生理作用及其应用前景。     

甘蓝植株挥发物对小菜蛾及半闭弯尾姬蜂寄主搜索行为的影响

研究了不同处理甘蓝植株释放的挥发物在小菜蛾及其寄生蜂半闭弯尾姬蜂寄主搜索行为中的作用．结果表明,机械损伤植株、虫损伤植株、虫一菜复合体植株释放的挥发物比完整植株释放的挥发物对小菜蛾和半闭弯尾姬蜂具有较强的引诱力,且以虫一菜复合体植株释放的挥发物引诱力最强．表明甘蓝受机械损伤或虫害后的挥发物对小菜蛾和半闭弯尾姬蜂起着重要的诱导作用．     

Plant defense guilds

Optimal plant defense should incorporate any mechanisms that influence the feeding behavior of potential pests. From a diverse collection of examples suggesting that the defense of a plant may be improved in the company of specific neighbors, we discuss a framework of operational mechanisms that begin to clarify some aspects of the recognized influence of species diversity on herbivory. Neighbors serve as insectary plants for herbivore predators and parasites, and influence herbivore feeding behavior by repelling, masking, attracting, and decoying. Insectary plants lower the numerical response of herbivores by increasing the efficiency of their predators and parasites. Repellent plants primarily lower functional response by causing the predator to fail to locate or reject its normal prey. Attractant-decoy plants dilute herbivore impact by drawing off herbivores, either increasing or decreasing their numerical and functional response (or either). The concept of gene conservation guilds adds diversionary and delaying tactics to the adaptation-counteradaptation view of plant-herbivore coevolution. The useful life of a given gene for resistance may best be extended by mechanisms that disrupt genetic tracking (specialization) by herbivores. Some plants may remain inedible not because their chemistry or morphology represents an evolutionary impasse, but because they live in an environment that provides acceptable options of variable quality. Feeding environments that provide little or no choice promote specialization by forcing physiological adaptation. Conversely, the evolutionary momentum of specializing herbivores may be lowered by enhancing their susceptibility, either by selection against virulent individuals, or by decreasing the exposure frequency of susceptible genotypes. The latter mechanism of conserving susceptible individuals takes advantage of herbivore behavioral sensitivity to variable plant quality. Direct selection against virulent genotypes requires temporal cycling of the herbivore population between resistant and nonresistant hosts. Both events may occur within defense guilds that provide acceptable feeding options of similar but distinctive quality.     

Chemical signals from host plant and sexual behavior in a moth

In the phytophagous corn earworm, Helicoverpa (Heliothis) zea, females delay their reproductive behaviors until they find a suitable host on which to deposit their eggs. Perception of volatile chemical signals from corn silk triggers the production of sex pheromone followed by its release, which leads to mating. Several natural corn silk volatiles, including the plant hormone ethylene, induced pheromone production in H. zea females. Because H. zea larvae feed on the fruiting parts of a wide variety of hosts, ethylene, which is associated with fruit ripening, could act as a common cue.