National Key Engineering Lab of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
Institute of Crop Science, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081, China.
J Exp Bot. 2023 Jun 27;74(12):3749-3764. doi: 10.1093/jxb/erad113.
The corn leaf aphid (Rhopalosiphum maidis) is a major maize pest that frequently causes substantial yield losses. Exploring the genetic basis of resistance to aphids is important for improving maize yield and quality. Here, we used a maize recombinant inbred line population derived from two parents with different susceptibility to aphids, B73 (susceptible) and Abe2 (resistant), and performed quantitative trait locus (QTL) mapping using aphid resistance scores as an indicator. We mapped a stable QTL, qRTA6, to chromosome 6 using data from 2 years of field trials, which explained 40.12-55.17% of the phenotypic variation. To further investigate the mechanism of aphid resistance in Abe2, we constructed transcriptome and metabolome libraries from Abe2 and B73 leaves with or without aphid infestation at different time points. Integrating QTL mapping and transcriptome data revealed three aphid resistance candidate genes (Zm00001d035736, Zm00001d035751, and Zm00001d035767) associated with the hypersensitive response, the jasmonic acid pathway, and protein ubiquitination. Integrated transcriptomic and metabolomic analysis revealed that the differentially expressed genes and metabolites were enriched in flavonoid biosynthesis. These findings extend our understanding of the molecular mechanisms controlling aphid resistance in maize, and the QTL and candidate genes are valuable resources for increasing this resistance.
玉米蚜（Rhopalosiphum maidis）是一种主要的玉米害虫，经常导致大量的产量损失。探索对蚜虫的抗性的遗传基础对于提高玉米的产量和质量非常重要。在这里，我们使用了一个由两个对蚜虫敏感性不同的亲本（B73（敏感）和 Abe2（抗性））衍生的玉米重组自交系群体，并用蚜虫抗性评分作为指标进行了数量性状位点（QTL）作图。我们在两年的田间试验数据中，将一个稳定的 QTL，qRTA6，定位到了 6 号染色体上，该 QTL 解释了 40.12-55.17%的表型变异。为了进一步研究 Abe2 对蚜虫的抗性机制，我们从 Abe2 和 B73 叶片中构建了转录组和代谢组文库，这些叶片在有无蚜虫侵染的情况下，在不同的时间点进行了研究。整合 QTL 作图和转录组数据揭示了三个与过敏反应、茉莉酸途径和蛋白质泛素化相关的蚜虫抗性候选基因（Zm00001d035736、Zm00001d035751 和 Zm00001d035767）。整合转录组和代谢组分析表明，差异表达的基因和代谢物在类黄酮生物合成中富集。这些发现扩展了我们对控制玉米蚜虫抗性的分子机制的理解，QTL 和候选基因是提高这种抗性的有价值的资源。
