College of Life Science and Resources and Environment, Yichun University, Yichun, 336000, China.
Sci Rep. 2022 Dec 22;12(1):22137. doi: 10.1038/s41598-022-26693-y.
Tomato (Solanum lycopersicum L.) is a major Solanaceae crop worldwide and is vulnerable to bacterial wilt (BW) caused by Ralstonia solanacearum during the production process. BW has become a growing concern that could enormously deplete the tomato yield from 50 to 100% and decrease the quality. Research on the molecular mechanism of tomato regulating BW resistance is still limited. In this study, two tomato inbred lines (Hm 2-2, resistant to BW; and BY 1-2, susceptible to BW) were used to explore the molecular mechanism of tomato in response to R. solanacearum infection by RNA-sequencing (RNA-seq) technology. We identified 1923 differentially expressed genes (DEGs) between Hm 2-2 and BY 1-2 after R. solanacearum inoculation. Among these DEGs, 828 were up-regulated while 1095 were down-regulated in R-3dpi (Hm 2-2 at 3 days post-inoculation with R. solanacearum) vs. R-mock (mock-inoculated Hm 2-2); 1087 and 2187 were up- and down-regulated, respectively, in S-3dpi (BY 1-2 at 3 days post-inoculation with R. solanacearum) vs. S-mock (mock-inoculated BY 1-2). Moreover, Gene Ontology (GO) enrichment analysis revealed that the largest amount of DEGs were annotated with the Biological Process terms, followed by Cellular Component and Molecular Function terms. A total of 114, 124, 85, and 89 regulated (or altered) pathways were identified in R-3dpi vs. R-mock, S-3dpi vs. S-mock, R-mock vs. S-mock, and R-3dpi vs. S-3dpi comparisons, respectively, by Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis. These clarified the molecular function and resistance pathways of DEGs. Furthermore, quantitative RT-PCR (qRT-PCR) analysis confirmed the expression patterns of eight randomly selected DEGs, which suggested that the RNA-seq results were reliable. Subsequently, in order to further verify the reliability of the transcriptome data and the accuracy of qRT-PCR results, WRKY75, one of the eight DEGs was silenced by virus-induced gene silencing (VIGS) and the defense response of plants to R. solanacearum infection was analyzed. In conclusion, the findings of this study provide profound insight into the potential mechanism of tomato in response to R. solanacearum infection, which lays an important foundation for future studies on BW.
番茄（Solanum lycopersicum L.）是世界范围内重要的茄科作物，在生产过程中易受青枯雷尔氏菌引起的细菌性萎蔫病（BW）的影响。BW 已成为一个日益严重的问题，可能导致番茄产量减少 50%至 100%，并降低其质量。目前，对番茄调节 BW 抗性的分子机制的研究仍很有限。本研究利用 RNA 测序（RNA-seq）技术，以番茄自交系 Hm 2-2（抗 BW）和 BY 1-2（感 BW）为材料，探讨番茄对青枯雷尔氏菌侵染的分子机制。我们在 Hm 2-2 接种青枯雷尔氏菌 3 天后（R-3dpi）与对照（mock 接种的 Hm 2-2）相比，鉴定出 1923 个差异表达基因（DEGs）。在这些 DEGs 中，828 个上调，1095 个下调；在 BY 1-2 接种青枯雷尔氏菌 3 天后（S-3dpi）与对照（mock 接种的 BY 1-2）相比，1087 个上调，2187 个下调。GO 富集分析表明，最大数量的 DEGs 被注释为生物学过程，其次是细胞成分和分子功能。在 R-3dpi 与 R-mock、S-3dpi 与 S-mock、R-mock 与 S-mock 和 R-3dpi 与 S-3dpi 比较中，分别鉴定出 114、124、85 和 89 个调控（或改变）途径。KEGG 通路分析表明，这些途径阐明了 DEGs 的分子功能和抗性途径。此外，通过定量 RT-PCR（qRT-PCR）分析对 8 个随机选择的 DEGs 的表达模式进行了验证，结果表明 RNA-seq 结果可靠。随后，为了进一步验证转录组数据的可靠性和 qRT-PCR 结果的准确性，我们通过病毒诱导的基因沉默（VIGS）沉默了 8 个 DEGs 中的一个 WRKY75，并分析了植物对青枯雷尔氏菌感染的防御反应。综上所述，本研究为番茄对青枯雷尔氏菌侵染的潜在机制提供了深入的见解，为未来 BW 的研究奠定了重要基础。
