Zhong Jiaqi, Situ Junjian, He Chengcheng, He Jiahui, Kong Guanghui, Li Huaping, Jiang Zide, Li Minhui
College of Plant Protection, South China Agricultural University, Guangzhou, GD 510642, China.
Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou, GD 510642, China.
Hortic Res. 2024 Dec 28;12(4):uhae361. doi: 10.1093/hr/uhae361. eCollection 2025 Apr.
Fungi produce microRNA-like RNAs (milRNAs) with functional importance in various biological processes. Our previous research identified a new milRNA -milR87 from f. sp. , which contributes to fungal virulence by targeting the pathogen glycosyl hydrolase encoding gene. However, the potential roles of fungal milRNAs in interactions with hosts are not well understood. This study demonstrated that -milR87 specifically suppressed the expression of , a pathogenesis-related gene that encodes a transcriptional activator in the banana ( Cavendish group cv. 'Baxi Jiao') genome, by targeting the 3'untranslated region (UTR) of . Transient overexpression of MaPTI6L activated plant defense responses that depend on its nuclear localization, yet co-expression with -milR87 attenuated these responses. MaPTI6L enhanced plant resistance by promoting transcription of the salicylic acid signaling pathway marker gene . Sequence analysis of the gene in 19 banana varieties, particularly those resistant to Fusarium wilt, uncovered single nucleotide polymorphisms (SNPs) at -milR87 target sites. Experimental validation showed that these SNPs significantly reduce the microRNA's ability to suppress target gene expression. Our findings reveal that -milR87 plays an important role in impairing plant resistance by targeting MaPTI6L mRNA and reducing transcription during the early infection stage, suggesting the 3'UTR of as a promising target for genome editing in generation of disease-resistant banana cultivars.
真菌产生在各种生物过程中具有功能重要性的微小RNA样RNA（milRNAs）。我们之前的研究从尖孢镰刀菌中鉴定出一种新的milRNA——milR87，它通过靶向病原体糖基水解酶编码基因来促进真菌毒力。然而，真菌milRNAs在与宿主相互作用中的潜在作用尚未得到充分了解。本研究表明，milR87通过靶向MaPTI6L的3'非翻译区（UTR），特异性抑制了香蕉（卡文迪什组品种‘巴西蕉’）基因组中一个编码转录激活因子的病程相关基因MaPTI6L的表达。MaPTI6L的瞬时过表达激活了依赖其核定位的植物防御反应，但与milR87共表达会减弱这些反应。MaPTI6L通过促进水杨酸信号通路标记基因的转录来增强植物抗性。对19个香蕉品种，特别是对枯萎病有抗性的品种中MaPTI6L基因的序列分析，在milR87靶位点发现了单核苷酸多态性（SNPs）。实验验证表明，这些SNPs显著降低了微小RNA抑制靶基因表达的能力。我们的研究结果表明，milR87在早期感染阶段通过靶向MaPTI6L mRNA并减少MaPTI6L转录来损害植物抗性方面发挥重要作用，这表明MaPTI6L的3'UTR作为抗病香蕉品种基因组编辑的一个有前景的靶点。
