RNA N6-adenine methylation dynamics impact Hyaloperonospora arabidopsidis resistance in Arabidopsis

Abstract

In plants, epitranscriptomic mark N6-adenine methylation (m6A) is dynamically regulated by (a)biotic stressors. However, there is limited knowledge on m6A dynamics at single nucleotide resolution on specific RNA molecule under stresses, and their role in environmental adaptation. By using Oxford Nanopore Technology direct RNA sequencing (ONT-DRS) and a neural network model, here we show transcript-specific dynamics of m6A modification at single nucleotide resolution by biotic stress during Hyaloperonospera arabidopsidis (Hpa) infection in Arabidopsis. In wild-type seedlings, pathogen infection causes significant reduction of global m6A ratios, which correlates with activation of m6A-modified transcripts. Defect of m6A deposition in the m6A mutant hakai-1 mimics m6A reduction from Hpa infection at [~]70% of sites, resulting in constitutive overexpression of basal defence genes and enhanced resistance against the pathogen. Our results demonstrate that m6A dynamics impact defence response against pathogen, providing a promising target for future crop improvement strategies.