Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, the Chinese Academy of Sciences, Guangzhou, 510650, China.
Key Laboratory of Tropical Fruit Biology, Ministry of Agriculture, South Subtropical Crops Research Institute, CATAS, Zhanjiang, 524091, China.
Funct Integr Genomics. 2020 Jul;20(4):551-562. doi: 10.1007/s10142-020-00734-z. Epub 2020 Feb 17.
Tropical race 4 of Fusarium oxysporum f. sp. cubense (FocTR4) is seriously threatening the banana industry worldwide. Resistant genotypes are present in wild relatives of banana, but little is known about the genetic and molecular mechanisms driving resistance responses. In this work, through in-depth expression analysis, we compared the responses of the resistant wild relative Musa acuminata ssp. burmanicoides (WTB) with the susceptible banana cultivar "Brizilian" (CAV, as it belongs to the Cavendish subgroup) to FocTR4 infection. Our findings showed that 1196 defense-related genes in the resistant WTB were differentially expressed genes (DEGs); only 358 defense-related DEGs were detected in CAV. DEGs related to pattern recognition receptors (PRRs) and disease resistance (R genes) were found in both genotypes, indicating the onset of both basal and specific defenses to FocTR4. Genes associated with cell wall modification exhibited a more remarkable upregulation in WTB than in CAV and might be involved in resistance during penetration steps. Our data also suggested that the high resistance of WTB is quantitatively driven with larger numbers and higher expression levels of defense-related DEGs. Fine-tuning studies to understand the resistance responses of WTB at early stages should be conducted to better support banana breeding programs. Further investigations are also required to validate the role of key genes screened in this study.
尖孢镰刀菌古巴专化型 4 号热带种（FocTR4）严重威胁着全球香蕉产业。香蕉野生近缘种中存在抗性基因型，但对驱动抗性反应的遗传和分子机制知之甚少。在这项工作中，通过深入的表达分析，我们比较了抗性野生近缘种 Musa acuminata ssp. burmanicoides（WTB）与易感香蕉品种“巴西”（CAV，因为它属于卡文迪什亚组）对 FocTR4 感染的反应。我们的研究结果表明，抗性 WTB 中有 1196 个防御相关基因是差异表达基因（DEGs）；而 CAV 中仅检测到 358 个防御相关 DEGs。在两种基因型中都发现了与模式识别受体（PRRs）和抗病（R 基因）相关的 DEGs，表明对 FocTR4 同时启动了基础防御和特异性防御。与细胞壁修饰相关的基因在 WTB 中的上调更为显著，而在 CAV 中的上调则不明显，这可能与细胞壁穿透步骤中的抗性有关。我们的数据还表明，WTB 的高抗性是由数量更多和防御相关 DEGs 表达水平更高的定量驱动的。应该进行精细调节研究，以了解 WTB 的早期抗性反应，从而更好地支持香蕉育种计划。还需要进一步的研究来验证本研究筛选的关键基因的作用。
