Fusarium wilt of banana, caused by Fusarium oxysporum f. sp. cubense (Foc), is one of the most damaging plant diseases known. Foc race 1 (R1) decimated the Gros Michel-based banana (Musa acuminata) trade, and now Foc tropical race 4 (TR4) threatens global production of its replacement, the Cavendish banana. Here population genomics revealed that all Cavendish banana-infecting Foc race 4 strains share an evolutionary origin distinct from that of R1 strains. Although TR4 lacks accessory chromosomes, it contains accessory genes at the ends of some core chromosomes that are enriched for virulence and mitochondria-related functions. Meta-transcriptomics revealed the unique induction of the entire mitochondrion-localized nitric oxide (NO) biosynthesis pathway upon TR4 infection. Empirically, we confirmed the unique induction of a NO burst in TR4, suggesting that nitrosative pressure may contribute to virulence. Targeted mutagenesis demonstrated the functional importance of fungal NO production and the accessory gene SIX4 as virulence factors.

香蕉枯萎病，由尖镰孢f. 引起。 sp。 cubense ( Foc ) 是已知最具破坏性的植物病害之一。 Foc品种 1 (R1) 摧毁了大米歇尔香蕉 ( Musa acuminata ) 贸易，现在Foc热带品种 4 (TR4) 威胁着其替代品卡文迪什香蕉的全球生产。群体基因组学揭示，所有感染卡文迪什香蕉的Foc 4 种菌株都具有与 R1 菌株不同的进化起源。虽然TR4缺乏辅助染色体，但它在一些核心染色体末端含有辅助基因，这些基因富集毒力和线粒体相关功能。宏转录组学揭示了 TR4 感染后整个线粒体定位的一氧化氮 (NO) 生物合成途径的独特诱导。根据经验，我们证实了 TR4 中 NO 爆发的独特诱导，这表明亚硝化压力可能有助于毒力。靶向诱变证明了真菌 NO 产生和辅助基因SIX4作为毒力因子的功能重要性。