Department of Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, China Jiliang University, Hangzhou, China.
Department of Algorithmic Bioinformatics, Heinrich Heine University, Düsseldorf, Germany.
DNA Res. 2017 Dec 1;24(6):635-648. doi: 10.1093/dnares/dsx031.
Ustilago esculenta, infects Zizania latifolia, and induced host stem swollen to be a popular vegetable called Jiaobai in China. It is the long-standing artificial selection that maximizes the occurrence of favourable Jiaobai, and thus maintaining the plant-fungi interaction and modulating the fungus evolving from plant pathogen to entophyte. In this study, whole genome of U. esculenta was sequenced and transcriptomes of the fungi and its host were analysed. The 20.2 Mb U. esculenta draft genome of 6,654 predicted genes including mating, primary metabolism, secreted proteins, shared a high similarity to related Smut fungi. But U. esculenta prefers RNA silencing not repeat-induced point in defence and has more introns per gene, indicating relatively slow evolution rate. The fungus also lacks some genes in amino acid biosynthesis pathway which were filled by up-regulated host genes and developed distinct amino acid response mechanism to balance the infection-resistance interaction. Besides, U. esculenta lost some surface sensors, important virulence factors and host range-related effectors to maintain the economic endophytic life. The elucidation of the U. esculenta genomic information as well as expression profiles can not only contribute to more comprehensive insights into the molecular mechanism underlying artificial selection but also into smut fungi-host interactions.
茭白黑粉菌感染菰，使其茎部肿大成为中国广受欢迎的蔬菜，称为茭白。长期的人工选择使有利茭白的发生最大化，从而维持了植物-真菌的相互作用，并调节了从植物病原菌到内生菌的真菌进化。在这项研究中，对茭白黑粉菌的全基因组进行了测序，并对真菌及其宿主的转录组进行了分析。该茭白黑粉菌的 20.2Mb 草图基因组包含 6654 个预测基因，包括交配、初级代谢、分泌蛋白，与相关黑粉菌具有高度相似性。但茭白黑粉菌更倾向于 RNA 沉默而不是重复诱导点防御，并且每个基因的内含子更多，表明其进化速度相对较慢。该真菌还缺乏一些氨基酸生物合成途径的基因，这些基因被上调的宿主基因所填补，并发展出独特的氨基酸响应机制来平衡感染-抗性相互作用。此外，茭白黑粉菌失去了一些表面传感器、重要的毒力因子和与宿主范围相关的效应子，以维持其经济内生生活。茭白黑粉菌基因组信息及其表达谱的阐明不仅有助于更全面地了解人工选择的分子机制，也有助于黑粉菌-宿主相互作用的研究。
