Lee Sungwoo, Cassone Bryan J, Wijeratne Asela, Jun Tae-Hwan, Michel Andrew P, Mian M A Rouf
Department of Entomology, Ohio Agricultural Research and Development Center (OARDC), The Ohio State University, Wooster, OH, 44691, USA.
Present Address: Department of Crop Science, Chungnam National University, Daejeon, 34341, South Korea.
BMC Genomics. 2017 Jun 23;18(1):472. doi: 10.1186/s12864-017-3829-9.
Genetic resistance of soybean [Glycine max (L.) Merr] against Aphis glycines provides effective management of this invasive pest, though the underlying molecular mechanisms are largely unknown. This study aimed to investigate genome-wide changes in gene expressions of soybean near-isogenic lines (NILs) either with the Rag5 allele for resistance or the rag5 allele for susceptibility to the aphid following infestation with soybean aphid biotype 2.
The resistant (R)-NIL responded more rapidly to aphid infestation than the susceptible (S)-NIL, with differential expressions of 2496 genes during first 12 h of infestation (hai), compared to the aphid-free control. Although the majority of the differentially expressed genes (DEGs) in the R-NIL also responded to aphid infestation in S-NIL, overall the response time was longer and/or the magnitude of change was smaller in the S-NIL. In addition, 915 DEGs in R-NIL continued to be regulated at all time points (0, 6, 12, and 48 hai), while only 20 DEGs did so in S-NIL. Enriched gene ontology of the 2496 DEGs involved in plant defense responses including primary metabolite catalysis, oxidative stress reduction, and phytohormone-related signaling. By comparing R- vs. S-NIL, a total of 556 DEGs were identified. Of the 13 genes annotated in a 120-kb window of the Rag5 locus, two genes (Glyma.13 g190200 and Glyma.13 g190600) were differentially expressed (upregulated in S- or R-NIL), and another gene (Glyma.13 g190500) was induced up to 4-fold in the R-NIL at 6 and 12 h following aphid infestation.
This study strengthens our understanding of the defense dynamics in compatible and incompatible interactions of soybean and soybean aphid biotype 2. Several DEGs (e.g., Glyma.13 g190200, Glyma.13 g190500, and Glyma.13 g190600) near the Rag5 locus are strong candidate genes for further investigations.
大豆[Glycine max (L.) Merr]对大豆蚜的遗传抗性为有效治理这种入侵害虫提供了途径，但其潜在分子机制仍 largely 未知。本研究旨在调查大豆近等基因系（NILs）在受到大豆蚜生物型 2 侵染后，携带抗蚜 Rag5 等位基因或感蚜 rag5 等位基因的基因表达在全基因组范围内的变化。
与未受蚜虫侵染的对照相比，抗性（R）-NIL 对蚜虫侵染的反应比感病（S）-NIL 更快，在侵染后的前 12 小时（hai）内有 2496 个基因差异表达。虽然 R-NIL 中大多数差异表达基因（DEGs）在 S-NIL 中也对蚜虫侵染有反应，但总体而言，S-NIL 的反应时间更长和/或变化幅度更小。此外，R-NIL 中的 915 个 DEGs 在所有时间点（0、6、12 和 48 hai）均持续受到调控，而 S-NIL 中只有 20 个 DEGs 如此。参与植物防御反应的 2496 个 DEGs 的基因本体富集包括初级代谢物催化、氧化应激降低和植物激素相关信号传导。通过比较 R-NIL 和 S-NIL，共鉴定出 556 个 DEGs。在 Rag5 基因座的 120-kb 窗口中注释的 13 个基因中，有两个基因（Glyma.13 g190200 和 Glyma.13 g190600）差异表达（在 S-NIL 或 R-NIL 中上调），另一个基因（Glyma.13 g190500）在蚜虫侵染后的 6 小时和 12 小时在 R-NIL 中被诱导上调至 4 倍。
本研究加深了我们对大豆与大豆蚜生物型 2 亲和与非亲和互作中防御动态的理解。Rag5 基因座附近的几个 DEGs（例如，Glyma.13 g190200、Glyma.13 g190500 和 Glyma.13 g190600）是进一步研究的有力候选基因。
