The fungus Aspergillus flavus can produce high, unsafe levels of aflatoxin in maize (Zea mays L.) and other high-oil seed crops under environmental conditions favoring fungal growth and sporulation. At high levels, aflatoxin can kill, and chronic exposure to lower levels causes liver cancer, stunted growth during childhood, and depressed immune systems in humans and animals. Aspergillus ear rot (AER) is especially problematic in tropical environments, but most gene identification studies have been done in temperate or subtropical maize. Thus, the objectives of this research include identifying and mapping chromosomal regions and genes associated with AER resistance in tropical maize inbred lines via genome-wide association study (GWAS) and tying these genes to metabolic pathways and potential resistance mechanisms. A panel of 320 tropical field corn and popcorn inbred lines was analyzed with phenotypic data for AER collected in two environments after harvest, and a set of 291,633 high-quality polymorphic single-nucleotide polymorphisms (SNPs) generated via genotyping by sequencing. Seven SNPs significantly associated with AER were identified. Pathway analysis identified 56 associated pathways, yielding possible resistance mechanisms related to flavonoid and phytoalexin plant compounds, plant signaling via hormones, starch biosynthesis, and general plant growth and metabolism. Many of the same genes were identified by both analyses, but GWAS and pathway analysis jointly identified more candidate genes than either alone.

中文翻译：

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一组热带玉米种质中黄曲霉耳腐病的关联作图及通路分析

真菌黄曲霉可以在玉米中产生高水平、不安全的黄曲霉毒素（Zea maysL.) 和其他有利于真菌生长和孢子形成的环境条件下的高油种子作物。黄曲霉毒素含量高时可致死，长期接触较低含量的黄曲霉毒素会导致肝癌、儿童期发育迟缓以及人类和动物的免疫系统低下。曲霉耳腐病 (AER) 在热带环境中尤其成问题，但大多数基因鉴定研究都是在温带或亚热带玉米中进行的。因此，本研究的目标包括通过全基因组关联研究 (GWAS) 识别和绘制与热带玉米自交系中 AER 抗性相关的染色体区域和基因，并将这些基因与代谢途径和潜在抗性机制联系起来。使用收获后在两种环境中收集的 AER 表型数据分析了 320 个热带田间玉米和爆米花自交系，并通过基因分型和测序生成了一组 291,633 个高质量多态性单核苷酸多态性 (SNP)。鉴定了七个与 AER 显着相关的 SNP。通路分析确定了 56 条相关通路，产生了与类黄酮和植物抗毒素植物化合物、通过激素的植物信号传导、淀粉生物合成以及一般植物生长和代谢相关的可能抗性机制。两种分析都鉴定了许多相同的基因，但 GWAS 和通路分析联合鉴定了比单独鉴定更多的候选基因。633 个高质量的多态性单核苷酸多态性 (SNP)，通过测序进行基因分型。鉴定了七个与 AER 显着相关的 SNP。通路分析确定了 56 条相关通路，产生了与类黄酮和植物抗毒素植物化合物、通过激素的植物信号传导、淀粉生物合成以及一般植物生长和代谢相关的可能抗性机制。两种分析都鉴定了许多相同的基因，但 GWAS 和通路分析联合鉴定了比单独鉴定更多的候选基因。633 个高质量的多态性单核苷酸多态性 (SNP)，通过测序进行基因分型。鉴定了七个与 AER 显着相关的 SNP。通路分析确定了 56 条相关通路，产生了与类黄酮和植物抗毒素植物化合物、通过激素的植物信号传导、淀粉生物合成以及一般植物生长和代谢相关的可能抗性机制。两种分析都鉴定了许多相同的基因，但 GWAS 和通路分析联合鉴定了比单独鉴定更多的候选基因。