N 6 -methyl-adenosine (m6A) is a prevalent RNA modification in many species. Abnormal m6A methylation levels can lead to RNA dysfunction and can cause diseases. Tobacco mosaic virus (TMV) is one of the most devastating viruses for agricultural plants. It has many hosts, particularly including tobacco and other members the family Solanaceae. However, it remains unclear whether the abnormal growth induced by TMV is associated with the m6A level. A rapid and accurate analytical method using ultra-high-performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UHPLC−HR − MS/MS) was developed to analyse the adenosine (A), cytidine (C), guanosine (G), uridine (U), and m6A contents in the tobacco leaf, and the m6A/G ratio was used to evaluate the m6A level. Subsequent protein sequence alignments were used to find the potential methylases and demethylases in Nicotiana tabacum (N. tabacum). Finally, reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was used to analyse the gene expression levels of the potential methylases and demethylases in the N. tabacum leaf. The results showed that TMV reduced the m6A level. Moreover, protein sequence alignments revealed partial homology among human ALKBH5, Arabidopsis (NP_001031793), and Nicotiana sylvestris (XP_009800010). The gene expression level of the potential demethylase XM_009801708 increased at 14 and 21 days in N. tabacum infected with TMV, whereas all of the potential methylases decreased. The reversible m6A modification in N. tabacum mRNA might represent a novel epigenetic mechanism involved in TMV.

Both indole and phenol structures are important active components of drug structure. In this study, a series of novel 3-indole pyrazole derivatives incorporating phenolic moieties were rationally designed and synthesized through molecular hybridization strategy. A comprehensive evaluation of antitumor activity demonstrated that these target compounds exhibited remarkable cytotoxicity across four distinct cancer cell lines. Notably, compound O11 emerged as the most potent compound, showing exceptional activity against human chronic myeloid leukemia (K562) cells with an IC₅₀ value of 2.64 μM. The investigation into the mechanism of transcription and protein validation revealed that the anti-tumor effects were produced through multiple pathways: potential interference with the mitochondrial membrane, modulated the intracellular levels of reactive oxygen species, inhibited the activation of the NF-κB signaling pathway, blockade of the cell cycle at the G2/M phase, and ultimately, apoptosis of the K562 cells. These findings underscore the potential of O11, a promising compound that offers new possibilities for the further development of cancer therapeutics. Graphical abstract In this study, 22 novel 3-indolylpyrazole phenoxyacetamide derivatives were synthesized. Among them, compound O11 (IC₅₀ = 2.6 μM) was identified as having excellent anti-proliferative activity against K562 cels. Mechanistic studies revealed that O11 exerted its antitumor effects by modulating intracellular ROS levels, mitochondrial membrane potential, and inhibiting the activation of NF-κB.