Wheat Health, Genetics and Quality Research Unit, USDA-ARS, Pullman, Washington, United States of America.
Department of Horticulture, Washington State University, Pullman, Washington, United States of America.
PLoS One. 2024 Aug 29;19(8):e0306533. doi: 10.1371/journal.pone.0306533. eCollection 2024.
Pratylenchus neglectus and P. thornei are among the most destructive root lesion nematodes of wheat in the Pacific Northwest, United States of America and throughout the world. The aim of this study was to determine whether both nematode species were similar in their ability to induce defense genes in roots of wheat genotype Scarlet, and whether a combination of both species induced a different pattern of gene induction than each species alone. The long-term aspect of the research was to identify nematode-inducible promoters for deploying defense genes in roots in breeding programs. The root transcriptomes of genotype Scarlet were obtained after a one-week infection period with each nematode species separately, or both species combined. Root defense gene expression was induced for all three treatments relative to the no-nematode control, but P. thornei affected expression to a greater extent compared to P. neglectus. The species combination induced the highest number of defense genes. This result was not predicted from nematode enumeration studies, in which P. thornei colonization was substantially lower than that of P. neglectus, and the nematode combination did not show a significant difference. Quantitative real time polymerase chain reaction (qRT-PCR) assays for Dehydrin2, Glucan endo-1,3-beta-glucosidase, 1-cys-Peroxiredoxin, Pathogenesis-related protein 1 and Late embryogenesis-abundant proteins 76 and group 3 authenticated the induction observed in the transcriptome data. In addition, a near-isogenic line of Scarlet harboring genetic resistance to fungal soilborne pathogens, called Scarlet-Rz1, showed similar or higher levels of defense gene expression compared to fungus-susceptible Scarlet in qRT-PCR assays. Finally, transcriptome expression patterns revealed nematode-inducible promoters that are responsive to both P. neglectus and P. thornei.
忽视滑刃线虫和松材线虫是美国太平洋西北地区乃至全球小麦最具破坏性的根结线虫之一。本研究旨在确定这两个线虫物种在诱导小麦 Scarlet 基因型根系防御基因的能力上是否相似，以及两种线虫的组合是否会诱导出与每种线虫单独处理不同的基因诱导模式。该研究的长期目标是确定能够在根中诱导防御基因的线虫诱导启动子，以便在育种计划中使用。分别用每个线虫物种或两种线虫的组合感染 Scarlet 基因型小麦一周后，获得了根转录组。与无线虫对照相比，所有三种处理都诱导了根防御基因的表达，但与忽视滑刃线虫相比，松材线虫的影响更大。线虫组合诱导了最多数量的防御基因。这一结果与线虫计数研究不一致，在该研究中，松材线虫的定殖明显低于忽视滑刃线虫，而且线虫组合没有表现出显著差异。脱水素 2、葡聚糖内切-1,3-β-葡糖苷酶、1-半胱氨酸过氧化物酶、病程相关蛋白 1 和晚期胚胎丰富蛋白 76 和组 3 的定量实时聚合酶链反应 (qRT-PCR) 分析证实了转录组数据中观察到的诱导。此外，一种对真菌土传病原体具有遗传抗性的 Scarlet 近等基因系，称为 Scarlet-Rz1，在 qRT-PCR 分析中表现出与易感 Scarlet 相似或更高水平的防御基因表达。最后，转录组表达模式揭示了对线虫诱导有反应的启动子，这些启动子对线虫和松材线虫都有反应。
