Corteva Agriscience, Johnston, Iowa, USA.
Mol Plant Pathol. 2023 Jul;24(7):742-757. doi: 10.1111/mpp.13319. Epub 2023 Mar 16.
Plant pathogens cause significant crop loss worldwide, and new resistance genes deployed to combat diseases can be overcome quickly. Understanding the existing resistance gene diversity within the germplasm of major crops, such as maize, is crucial for the development of new disease-resistant varieties. We analysed the nucleotide-binding leucine-rich repeat receptors (NLRs) of 26 recently sequenced diverse founder lines from the maize nested association mapping (NAM) population and compared them to the R gene complement present in a wild relative of maize, Zea luxurians. We found that NLRs in both species contain a large diversity of atypical integrated domains, including many domains that have not previously been found in the NLRs of other species. Additionally, the single Z. luxurians genome was found to have greater integrated atypical domain diversity than all 26 NAM founder lines combined, indicating that this species may represent a rich source of novel resistance genes. NLRs were also found to have very high sequence diversity and presence-absence variation among the NAM founder lines, with a large NLR cluster on Chr10 representing a diversity hotspot. Additionally, NLRs were shown to be mobile within maize genomes, with several putative interchromosomal translocations identified.
植物病原体在全球范围内造成了重大的作物损失，而部署用于对抗疾病的新抗性基因很快就会被克服。了解玉米等主要作物种质中现有抗性基因的多样性对于开发新的抗病品种至关重要。我们分析了 26 个最近测序的玉米嵌套关联作图（NAM）群体的不同起始线的核苷酸结合亮氨酸重复受体（NLRs），并将它们与玉米野生近缘种大刍草中的 R 基因组成进行了比较。我们发现，这两个物种的 NLRs 都包含大量的非典型整合结构域，其中包括许多以前在其他物种的 NLRs 中未发现的结构域。此外，单个大刍草基因组被发现具有比 26 个 NAM 起始线组合更多的整合非典型结构域多样性，这表明该物种可能是新型抗性基因的丰富来源。NLRs 在 NAM 起始线中也表现出非常高的序列多样性和存在缺失变异，Chr10 上的一个大型 NLR 簇代表了一个多样性热点。此外，NLRs 被证明在玉米基因组中具有很高的移动性，鉴定出了几个推定的染色体间易位。
