Graduate School of Agricultural Science, Kobe University, Rokkodai, Nada-ku, Kobe, 657-8501, Japan.
Iwate Biotechnology Research Center, Narita,, Kitakami, Iwate, 024-0003, Japan.
Plant Cell Rep. 2021 Apr;40(4):605-619. doi: 10.1007/s00299-020-02658-1. Epub 2021 Jan 18.
Fusarium yellows resistant and susceptible lines in Brassica rapa showed different salicylic acid responses; the resistant line showed a similar response to previous reports, but the susceptible line differed. Fusarium yellows caused by Fusarium oxysporum f. sp. conglutinans (Foc) is an important disease. Previous studies showed that genes related to salicylic acid (SA) response were more highly induced following Foc infection in Brassica rapa Fusarium yellows resistant lines than susceptible lines. However, SA-induced genes have not been identified at the whole genome level and it was unclear whether they were up-regulated by Foc inoculation. Transcriptome analysis with and without SA treatment in the B. rapa Fusarium yellows susceptible line 'Misugi' and the resistant line 'Nanane' was performed to obtain insights into the relationship between SA sensitivity/response and Fusarium yellows resistance. 'Nanane's up-regulated genes were related to SA response and down-regulated genes were related to jasmonic acid (JA) or ethylene (ET) response, but differentially expressed genes in 'Misugi' were not. This result suggests that Fusarium yellows resistant and susceptible lines have a different SA response and that an antagonistic transcription between SA and JA/ET responses was found only in a Fusarium yellows resistant line. SA-responsive genes were induced by Foc inoculation in Fusarium yellows resistant (RJKB-T23) and susceptible lines (RJKB-T24). By contrast, 39 SA-induced genes specific to RJKB-T23 might function in the defense response to Foc. In this study, SA-induced genes were identified at the whole genome level, and the possibility, the defense response to Foc observed in a resistant line could be mediated by SA-induced genes, is suggested. These results will be useful for future research concerning the SA importance in Foc or other diseases resistance in B. rapa.
在芸薹属中，对黄萎病（由尖孢镰刀菌复合种引起）具有抗性和敏感性的品系表现出不同的水杨酸（SA）响应；抗性品系的响应与之前的报道相似，但敏感性品系则不同。黄萎病是由尖孢镰刀菌复合种引起的一种重要病害。先前的研究表明，与感病品系相比，在芸薹属黄萎病抗性品系中，与 SA 响应相关的基因在尖孢镰刀菌复合种侵染后被更高地诱导。然而，在全基因组水平上尚未鉴定出 SA 诱导的基因，也不清楚它们是否是由尖孢镰刀菌复合种接种而被上调的。在芸薹属黄萎病敏感品系“Misugi”和抗性品系“Nanane”中进行了有和没有 SA 处理的转录组分析，以深入了解 SA 敏感性/响应与黄萎病抗性之间的关系。“Nanane”上调的基因与 SA 响应有关，而下调的基因与茉莉酸（JA）或乙烯（ET）响应有关，但“Misugi”中差异表达的基因则没有。这一结果表明，感病和抗性品系具有不同的 SA 响应，并且仅在黄萎病抗性品系中发现了 SA 和 JA/ET 响应之间的拮抗转录。接种尖孢镰刀菌复合种后，在黄萎病抗性（RJKB-T23）和敏感品系（RJKB-T24）中诱导了 SA 响应基因。相比之下，39 个仅在 RJKB-T23 中特异诱导的 SA 响应基因可能在对尖孢镰刀菌复合种的防御反应中发挥作用。在本研究中，在全基因组水平上鉴定了 SA 诱导的基因，并提出了在抗性品系中观察到的对尖孢镰刀菌复合种的防御反应可能是由 SA 诱导的基因介导的可能性。这些结果将有助于未来研究芸薹属中 SA 在尖孢镰刀菌复合种或其他病害抗性中的重要性。
