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一个由数国科研人员组成的研究小组日前成功破译了大麦的主要致病真菌——禾本科布氏白粉菌的基因组。这项成果将有助于人们了解真菌的特性，从而研究出防治植物病虫害的新方法。

这项研究由美国、法国、英国、德国、丹麦等国的研究人员合作完成。研究者在最新一期美国《科学》杂志上报告说，真菌是植物的主要致病因素，在漫长的进化过程中，它们与植物之间形成了复杂的互动关系。此次研究人员破译了禾本科布氏白粉菌的基因组，它仅包含6000个基因，是其他真菌基因组的一半，其结构远比想象中简单。

这种真菌由于缺乏一些关键基因，甚至无法合成破坏植物细胞壁的蛋白质，但它含有的大量基因却能让真菌蛋白质轻而易举地在植物细胞内“落户”，为该真菌染色体的重组和复制提供便利。

研究人员说，禾本科布氏白粉菌之所以具有这样的特性，可能是因为其最初的适应能力较强，能轻易地在大麦作物上繁衍生长，它也由此丧失了部分基因，完全依赖宿主存活，这可以解释为什么它并不会完全摧毁大麦，而是与其共生。（转载自生物谷）

原文出处：

Science DOI: 10.1126/science.1194573

Genome Expansion and Gene Loss in Powdery Mildew Fungi Reveal Tradeoffs in Extreme Parasitism

Pietro D. Spanu1,*, James C. Abbott1,?, Joelle Amselem2,15,?, Timothy A. Burgis1,?, Darren M. Soanes3,?, Kurt Stüber4,?, Emiel Ver Loren van Themaat4,?, James K. M. Brown5,?, Sarah A. Butcher1,?, Sarah J. Gurr6,?, Marc-Henri Lebrun15,?, Christopher J. Ridout5,?, Paul Schulze-Lefert4,?, Nicholas J. Talbot3,?, Nahal Ahmadinejad4, Christian Ametz1, Geraint R. Barton1, Mariam Benjdia4, Przemyslaw Bidzinski4, Laurence V. Bindschedler7, Maike Both1, Marin T. Brewer8, Lance Cadle-Davidson9,10,?, Molly M. Cadle-Davidson9, Jerome Collemare2,§, Rainer Cramer7, Omer Frenkel8, Dale Godfrey11, James Harriman9, Claire Hoede2, Brian C. King8, Sven Klages12, Jochen Kleemann4, Daniela Knoll4, Prasanna S. Koti4, Jonathan Kreplak2, Francisco J. López-Ruiz5, Xunli Lu4, Takaki Maekawa4, Siraprapa Mahanil9, Cristina Micali4, Michael G. Milgroom8, Giovanni Montana1, Sandra Noir4,||, Richard J. O’Connell4, Simone Oberhaensli13, Francis Parlange13, Carsten Pedersen11, Hadi Quesneville2, Richard Reinhardt12, Matthias Rott4, Soledad Sacristán14, Sarah M. Schmidt4,?, Moritz Sch?n4, Pari Skamnioti6, Hans Sommer4, Amber Stephens4, Hiroyuki Takahara4, Hans Thordal-Christensen11, Marielle Vigouroux6, Ralf We?ling4, Thomas Wicker13 and Ralph Panstruga4,*

Abstract

Powdery mildews are phytopathogens whose growth and reproduction are entirely dependent on living plant cells. The molecular basis of this life-style, obligate biotrophy, remains unknown. We present the genome analysis of barley powdery mildew, Blumeria graminis f.sp. hordei (Blumeria), as well as a comparison with the analysis of two powdery mildews pathogenic on dicotyledonous plants. These genomes display massive retrotransposon proliferation, genome-size expansion, and gene losses. The missing genes encode enzymes of primary and secondary metabolism, carbohydrate-active enzymes, and transporters, probably reflecting their redundancy in an exclusively biotrophic life-style. Among the 248 candidate effectors of pathogenesis identified in the Blumeria genome, very few (less than 10) define a core set conserved in all three mildews, suggesting that most effectors represent species-specific adaptations.