Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan.
Iwate Biotechnology Research Center, Narita, Kitakami, Iwate, 024-0003, Japan.
Sci Rep. 2023 May 26;13(1):8599. doi: 10.1038/s41598-023-35205-5.
Albugo candida causing white rust disease decreases the yield of Brassica rapa vegetables greatly. Resistant and susceptible cultivars in B. rapa vegetables have different immune responses against A. candida inoculation, however, the mechanism of how host plants respond to A. candida is still unknown. Using RNA-sequencing, we identified differentially expressed genes (DEGs) between A. candida inoculated [48 and 72 h after inoculation (HAI)] and non-inoculated samples in resistant and susceptible cultivars of komatsuna (B. rapa var. perviridis). Functional DEGs differed between the resistant and susceptible cultivars in A. candida inoculated samples. Salicylic acid (SA) responsive genes tended to be changed in their expression levels by A. candida inoculation in both resistant and susceptible cultivars, but different genes were identified in the two cultivars. SA-dependent systemic acquired resistance (SAR) involving genes were upregulated following A. candida inoculation in the resistant cultivar. Particular genes categorized as SAR that changed expression levels overlapped between A. candida and Fusarium oxysporum f. sp. conglutinans inoculated samples in resistant cultivar, suggesting a role for SAR in defense response to both pathogens particularly in the effector-triggered immunity downstream pathway. These findings will be useful for understanding white rust resistance mechanisms in B. rapa.
致病疫霉引起的白菜白锈病会极大地降低白菜类蔬菜的产量。白菜类蔬菜的抗病和感病品种对致病疫霉接种有不同的免疫反应，但宿主植物如何对致病疫霉做出响应的机制尚不清楚。通过 RNA 测序，我们在抗病和感病品种的小松菜（白菜亚种芸薹）中，鉴定了接种和未接种致病疫霉（接种后 48 和 72 小时）的样本之间的差异表达基因（DEGs）。接种致病疫霉后，抗病和感病品种之间的功能 DEGs 存在差异。在抗病和感病品种中，水杨酸（SA）响应基因的表达水平在致病疫霉接种后都有变化，但在两个品种中鉴定到的基因不同。抗病品种中与 SA 依赖的系统性获得抗性（SAR）相关的基因在接种致病疫霉后上调。在抗病品种中，与 SAR 相关的特定基因的表达水平在致病疫霉和尖孢镰刀菌 f. sp. 芸薹侵染样本中发生变化，这表明 SAR 在防御两种病原体的效应触发免疫下游途径中的作用。这些发现将有助于理解白菜对白锈病的抗性机制。
