代写被抓：防御共生体研究

代写被抓：防御共生体研究

几乎所有的昆虫都有很多天敌。防御共生体可以帮助宿主避免来自自然敌人的攻击。直接地说，由于细菌通常具有致病性基因，并产生具有毒素或阻抑作用的生物活性物质。在共生关系中，昆虫具有这些防御特性。间接地，共生可以刺激宿主启动免疫系统抵御入侵或“争夺”有限的宿主资源。这一领域是当前研究的热点。因为昆虫和共生体之间的相互作用可以用更高的营养水平来解释。汉密尔顿氏体防御已被确定为一种防御共生体之间的联系。pisum和寄生蜂Aphidius ervi。H.defensa降低了A.ervi的寄生率。对共生体基因型进行了分子水平的分析;说明毒性直接对拟寄生物幼虫产生负面影响。蚜虫携带h.s aphid的抗性是通过引起拟寄生物发育幼虫的死亡而获得的，而拟寄生物幼虫的死亡通常是由拟寄生物幼虫死亡引起的。

代写被抓：防御共生体研究
尽管有些蚜虫能成功地发育成成虫，但与没有防御系统的无共生蚜虫相比，它们的健康状况有所下降。大多数H. defensa菌株被认为对A. ervi具有保护作用。防御工蜂是一种生活在蚜虫共生体内的细菌。描述了昆虫王域菌与Photorhabdus之间的关系。与其他内共生体一致，它的重点是为蚜虫提供针对拟寄生物的保护。它也因烟粉虱的栖息地而闻名。这表明H. defensa保护蚜虫不受A. ervi的侵害。不同的H.defensa菌株具有不同程度的保护作用，从减少寄生小到完全覆盖。从克拉西沃拉蚜虫中分离出一株H.防御菌株，对A.ervi也有抗性。我们已经知道，一些直接的保护途径是通过毒素杀死蚜虫的寄生性幼虫。但有关诱导植物防御的间接保护途径会降低寄生蜂的引诱力的研究还很少。

代写被抓：防御共生体研究

Virtually all insects have a lot of natural enemies. Defensive symbionts can help their host avoid attacking from nature enemies. Directly, since bacteria usually possess pathogenicity genes and produce bio-active contents that function as toxins or deterrents. During symbiotic associations, insects will have these defensive properties. Indirectly, symbiont can stimulate to start the host immune system against invasions or “fight for” limited host resources. This area is real hot in current research. For the interactions between insects and symbionts can be explained in higher trophic levels.Hamiltonella defensa has been identified as a defensive symbiont in the association between A.pisum and parasitoid Aphidius ervi. The H.defensa reduced the rate of parasitism of A.ervi. The analyses of symbiont genotype on molecular level have been shown; it suggested that toxicity is directly giving negative impact to the parasitoid larva. The resistance of aphid carrying H.defensa is conferred by causing mortality of developing larvae of the parasitoid, which usually kill the parasitoid larva.

代写被抓：防御共生体研究
Although some will develop into adults successfully, compared to regular growth from the symbiont- free aphids without H.defensa, they suffer reducing fitness. Most strains of H. defensa are conferred to have protective function against A. ervi. H. Defensa is a bacteria living in a symbiont of aphids. It depicts the relationship between Regiella insecticola and Photorhabdus. In alignment with other endosymbionts, it focuses on providing protection to aphids against parasitoids. It is also well known for the habitation of Bemisia tabaci. This shows H. defensa protect aphids from A. ervi. Different H.defensa strains have different level of protecting effect, from small reduction of parasitism to being completely covered. One strain of H. defense have been isolated from aphids craccivora, also have resistance to A.ervi.21 It is already known that some about the direct protect pathway is via toxin to kill parasitoid larva in the aphids. But about indirect protect pathway of inducing plant defenses will reduce attraction of parasitoid wasps is known little.