附生于其它細(xì)胞體內(nèi)的胞內(nèi)共生關(guān)系 (Endosymbiotic relationships),，通常被認(rèn)為是一種寄生性的行為,，不過最新的一項(xiàng)研究卻證實(shí)，一種真菌細(xì)胞里所發(fā)現(xiàn)的共生細(xì)菌，卻是真菌細(xì)胞進(jìn)行生理活動(dòng)所必須,。
據(jù)了解這個(gè)由德國自然產(chǎn)物與感染生物研究院 (Natural Product Research and Infection Biology) Leibniz 研究所(Leibniz Institute) 科學(xué)家,，Laila Partida和 Christian Hertweck所共同參與的研究計(jì)劃，發(fā)現(xiàn)屬于真菌 Rhizopus microsporus 的細(xì)胞里,，存在著一種稱為Burkholderia 的細(xì)菌,，研究人員深入的分析，發(fā)現(xiàn)這兩個(gè)共生在一起的微生物,，居然可以共同的參與代謝,，分解植物植株幼苗，造成所謂幼苗枯萎病(seedling blight) 的發(fā)生,，研究人員還發(fā)現(xiàn),，Burkholderia 細(xì)菌所分泌的毒素rhizoxin，在真菌引發(fā)幼苗枯萎病的關(guān)鍵過程中,，扮演著不可缺少的角色,。
此外研究人員如果施用抗生素，來截殺真菌里的細(xì)菌,，結(jié)果雖然可以有效的防治細(xì)菌的存在,，但原為宿主角的真菌，也失去了生殖復(fù)制的功能,。
這些現(xiàn)象違反了長(zhǎng)久以來科學(xué)家的觀點(diǎn),，認(rèn)為寄生在他種生物細(xì)胞內(nèi)的細(xì)菌，多為對(duì)宿主引發(fā)不良反應(yīng)的作用,，從沒想過寄生的細(xì)菌,，也是參與宿主細(xì)胞代謝重要的一環(huán)，成為互利共生 (mutualism)最好的一個(gè)例子,。
(資料來源 : biocompare)
原始出處: http://news.biocompare.com/newsstory.asp?id=177464
部分英文原文：
Current Biology
10.1016/j.cub.2007.03.039
Report
Endosymbiont-Dependent Host Reproduction Maintains Bacterial-Fungal Mutualism
Laila P. Partida-Martinez1, Shamci Monajembashi2, Karl-Otto Greulich2 and Christian Hertweck1, 3, ,
1Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), 07745 Jena, Germany
2Leibniz Institute for Age Research, Fritz Lipmann Institute (FLI), 07745 Jena, Germany
3Friedrich-Schiller-University, 07745 Jena, Germany
Received 8 February 2007; revised 1 March 2007; accepted 7 March 2007. Published online: April 5, 2007. Available online 5 April 2007.
Summary
[NextPage]
Bacterial endosymbionts play essential roles for many organisms, and thus specialized mechanisms have evolved during evolution that guarantee the persistence of the symbiosis during or after host reproduction 1 and 2. The rice seedling blight fungus Rhizopus microsporus represents a unique example of a mutualistic life form in which a fungus harbors endobacteria (Burkholderia sp.) for the production of a phytotoxin [3]. Here we report the unexpected observation that in the absence of endosymbionts, the host is not capable of vegetative reproduction. Formation of sporangia and spores is restored only upon reintroduction of endobacteria. To monitor this process, we succeeded in GFP labeling cultured endosymbionts. We also established a laserbeam transformation technique for the first controlled introduction of bacteria into fungi to observe their migration to the tips of the aseptate hyphae. The persistence of this fungal-bacterial mutualism through symbiont-dependent sporulation is intriguing from an evolutionary point of view and implies that the symbiont produces factors that are essential for the fungal life cycle. Reproduction of the host has become totally dependent on endofungal bacteria, which in return provide a highly potent toxin for defending the habitat and accessing nutrients from decaying plants. This scenario clearly highlights the significance for a controlled maintenance of this fungal-bacterial symbiotic relationship.
Author Keywords: EVO_ECOL
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