mA RNA demethylase AtALKBH9B promotes mobilization of a heat-activated long terminal repeat retrotransposon in .

Transposons are mobile and ubiquitous DNA molecules that can cause vast genomic alterations. In plants, it is well documented that transposon mobilization is strongly repressed by DNA methylation; however, its regulation at the posttranscriptional level remains relatively uninvestigated. Here, we suggest that transposon RNA is marked by mA RNA methylation and can be localized in stress granules (SGs). Intriguingly, SG-localized AtALKBH9B selectively demethylates a heat-activated retroelement, , and thereby releases it from spatial confinement, allowing for its mobilization. In addition, we show evidence that mA RNA methylation contributes to transpositional suppression by inhibiting virus-like particle assembly and extrachromosomal DNA production. In summary, this study unveils a previously unknown role for mA in the suppression of transposon mobility and provides insight into how transposons counteract the mA-mediated repression mechanism by hitchhiking the RNA demethylase of the host.