Genome-Wide Identification and Expression Analysis of m⁶A Regulators in Bursaphelenchus xylophilus Across...

m⁶A represents a prevalent epitranscriptomic modification in eukaryotes. The dynamic balance of m⁶A modification is governed by methyltransferases (writers), demethylases (erasers), and binding proteins (readers). m⁶A regulators are integral to critical biological processes, including embryonic development, cell differentiation, and stress responses. B. xylophilus, a highly destructive invasive plant-parasitic nematode, has caused considerable ecological and economic damage worldwide. However, the m⁶A regulatory system in PWNs has not yet been investigated. In this study, we systematically identified 21 m⁶A regulators in PWNs, including 10 writers, 6 erasers, and 5 readers, which belong to the METTL, ALKBH, and KH/RRM families. Phylogenetic and domain analyses revealed the evolutionary conservation and functional diversification of these protein families. Expression profiling indicated stage-specific expression patterns of m⁶A regulators during the egg, larval, diapause, and adult stages. Furthermore, significant responses were observed under low-temperature treatment, β-pinene exposure, and infection of Pinus thunbergii seedlings, with ALKBH family members exhibiting upregulation under all three stress conditions. Notably, unlike most eukaryotes, the PWN lacks canonical FTO/ALKBH5 demethylases and YTH-domain readers, instead relying on ALKBH6/8 and KH/RRM proteins. These findings suggest that this non-canonical m⁶A regulatory mechanism may contribute to the development and pathogenesis of B. xylophilus.