背景:JUB1,一个含有过氧化氢诱导的转录因子的NAC结构域,在植物免疫中起着至关重要的作用。关于JUB1对小麦叶锈病的反应知之甚少。基因组学的最新发现也揭示了许多通常被认为是无功能的sORF,主张将它们纳入翻译的潜在监管参与者的必要性。然而,SORF上的甲基化是否跨越JUB1等调节基因的3UTR调节基因表达,尚不清楚。
结果:在这项研究中,我们鉴定了小麦JUB1同源基因3UTR中两个sORF的甲基化状态,TaJUB1-L,CpG中的胞嘧啶残基,在小麦的两个近等基因系(HD2329)中,在疾病进展的不同时间点的CHH和CHG位点,在叶锈病发病过程中有无Lr24基因。这里,我们报告了在感染后24小时后,耐药等值线中3'UTR的sORF中发生的CpG二核苷酸的显着去甲基化。此外,通过RT-qPCR观察到的上调基因表达与sORF中CpG位点的去甲基化成正比。
结论:我们的发现表明,TaJUB1-L可能是在叶锈病发病过程中提供耐受性的正调节因子,3'UTR的胞嘧啶甲基化可能充当其表达控制的开关。这些结果丰富了常规甲基化测定技术的潜在益处,用于以具有成本效益和机密的结论性方式在植物-病原体相互作用期间解开表观遗传学中未探索的谜团。
BACKGROUND: JUB1, a NAC domain containing hydrogen peroxide-induced transcription factor, plays a critical role in plant immunity. Little is known about how JUB1 responds to leaf rust disease in wheat. Recent discoveries in genomics have also unveiled a multitude of sORFs often assumed to be non-functional, to argue for the necessity of including them as potential regulatory players of translation. However, whether methylation on sORFs spanning the 3\'UTR of regulatory genes like JUB1 modulate gene expression, remains unclear.
RESULTS: In this
study, we identified the methylation states of two sORFs in 3\'UTR of a homologous gene of JUB1 in wheat, TaJUB1-L, at cytosine residues in CpG, CHH and CHG sites at different time points of disease progression in two near-isogenic lines of wheat (HD2329), with and without Lr24 gene during leaf rust pathogenesis. Here, we report a significant demethylation of the CpG dinucleotides occurring in the sORFs of the 3\'UTR in the resistant isolines after 24 h post-infection. Also, the up-regulated gene expression observed through RT-qPCR was directly proportional to the demethylation of the CpG sites in the sORFs.
CONCLUSIONS: Our findings indicate that TaJUB1-L might be a positive regulator in providing tolerance during leaf rust pathogenesis and cytosine methylation at 3\'UTR might act as a switch for its expression control. These results enrich the potential benefit of conventional methylation assay techniques for unraveling the unexplored enigma in epigenetics during plant-pathogen interaction in a cost-effective and confidentially conclusive manner.