Plant Journal:农科院水稻研究所解析真菌-植物互作共生分子机理

大家都知道水稻是什么，但很少知道菰(读作gū)为何物?其实，菰是我国早期主要谷类作物之一，它的种子叫菰米或雕胡米，为“六谷”之一，在我国古代诗词中有大量描述，赞美其香美可口;但其后来被水稻取代，目前栽培种已消失。同时，菰会受到黑粉真菌侵染，形成长期共生关系;受侵染的菰可以形成可食用的鲜嫩膨大茎，被我们祖先驯化成蔬菜作物——茭白。该菌-寄主共生关系，为研究宿主在病原体长期侵染下基因组的适应性分化提供了一个难得的遗传材料。

近日，由中国水稻研究所郭龙彪研究员和浙江大学樊龙江教授等团队开展合作研究，通过野生菰和茭白基因组测序以及转录组分析，共预测到43000多个菰基因，其中包含大量核苷酸结合位点(NBS)类抗性基因;发现其与水稻有高度基因组共线性，共鉴定出共线性模块1498个，涵盖50.9%菰基因组基因。通过比较基因组分析，揭示了宿主茭白基因组抗性免疫受体因子相关基因大量缺失和抑制是有益菌-寄主长期共生的关键。相关研究成果于2015年6月在线发表在国际知名刊物《植物杂志(Plant Journal)》上。真菌-植物互作共生分子机理的解析，对创新型农业育种利用与植物保护具有重要的理论意义和应用价值。

原文链接：

A host plant genome (Zizania latifolia) after a century-long endophyte infection

原文摘要：

Despite the importance of host–microbe interactions in natural ecosystems, agriculture and medicine, the impact of long-term (especially decades or longer) microbial colonization on the dynamics of host genomes is not well understood. The vegetable crop ‘Jiaobai’ with enlarged edible stems was domesticated from wildZizania latifolia (Oryzeae) approximately 2000 years ago as a result of persistent infection by a fungal endophyte, Ustilago esculenta. Asexual propagation via infected rhizomes is the only means of Jiaobai production, and the Z. latifolia–endophyte complex has been maintained continuously for two centuries. Here, genomic analysis revealed that cultivated Z. latifolia has a significantly smaller repertoire of immune receptors compared with wild Z. latifolia. There are widespread gene losses/mutations and expression changes in the plant–pathogen interaction pathway in Jiaobai. These results show that continuous long-standing endophyte association can have a major effect on the evolution of the structural and transcriptomic components of the host genome.

DOI: 10.1111/tpj.12912

作者：郭龙彪和樊龙江