Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, Ottawa, Canada.
Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Canada.
BMC Genomics. 2021 Aug 4;22(1):591. doi: 10.1186/s12864-021-07617-y.
Fusarium head blight is a disease of global concern that reduces crop yields and renders grains unfit for consumption due to mycotoxin contamination. Fusarium poae is frequently associated with cereal crops showing symptoms of Fusarium head blight. While previous studies have shown F. poae isolates produce a range of known mycotoxins, including type A and B trichothecenes, fusarins and beauvericin, genomic analysis suggests that this species may have lineage-specific accessory chromosomes with secondary metabolite biosynthetic gene clusters awaiting description.
We examined the biosynthetic potential of 38 F. poae isolates from Eastern Canada using a combination of long-read and short-read genome sequencing and untargeted, high resolution mass spectrometry metabolome analysis of extracts from isolates cultured in multiple media conditions.
A high-quality assembly of isolate DAOMC 252244 (Fp157) contained four core chromosomes as well as seven additional contigs with traits associated with accessory chromosomes. One of the predicted accessory contigs harbours a functional biosynthetic gene cluster containing homologs of all genes associated with the production of apicidins. Metabolomic and genomic analyses confirm apicidins are produced in 4 of the 38 isolates investigated and genomic PCR screening detected the apicidin synthetase gene APS1 in approximately 7% of Eastern Canadian isolates surveyed.
Apicidin biosynthesis is linked to isolate-specific putative accessory chromosomes in F. poae. The data produced here are an important resource for furthering our understanding of accessory chromosome evolution and the biosynthetic potential of F. poae.
镰刀菌穗腐病是一种全球性关注的疾病，它会降低作物产量，并由于霉菌毒素污染而使谷物不适宜食用。禾谷镰刀菌通常与表现出镰刀菌穗腐病症状的谷类作物有关。虽然先前的研究表明，禾谷镰刀菌分离株会产生一系列已知的霉菌毒素，包括 A 型和 B 型单端孢霉烯族毒素、呋孢素和 beauvericin，但基因组分析表明，该物种可能具有谱系特异性的辅助染色体，其中包含有待描述的次级代谢生物合成基因簇。
我们使用长读长和短读长基因组测序以及针对在多种培养条件下培养的分离株的提取物进行非靶向、高分辨率质谱代谢组学分析的组合，检查了来自加拿大东部的 38 株禾谷镰刀菌分离株的生物合成潜力。
分离株 DAOMC 252244（Fp157）的高质量组装包含四个核心染色体以及另外七个与辅助染色体相关的特征的附加连续体。预测的辅助连续体之一包含一个功能生物合成基因簇，其中包含与 apicidins 生产相关的所有基因的同源物。代谢组学和基因组分析证实，在所研究的 38 个分离株中，有 4 个分离株产生了 apicidins，并且对大约 7%的加拿大东部调查分离株进行的基因组 PCR 筛选检测到了 apicidin 合成酶基因 APS1。
apicidin 生物合成与禾谷镰刀菌中特定于分离株的假定辅助染色体相关。这里产生的数据是进一步了解辅助染色体进化和禾谷镰刀菌生物合成潜力的重要资源。
