Enhanced HSP70 Binding to m6A-Methylated RNAs Facilitates Cold Stress Adaptation in Mango Seedlings
Cold stress poses a serious challenge to tropical fruit production, particularly in mango. N6-methyladenosine (m6A) modifications are key regulators of gene expression, enabling plants to stress responses, enhancing adaptation and improving resilience to environmental challenges. In our study, transcriptome-wide m6A methylation profiling under cold stress identified 6,499 differentially methylated m6A peaks and 2,164 differentially expressed genes (DEGs) in mango seedlings. Among these, six genes were hyper-upregulated, 21 were hyper-downregulated, and 26 were hypo-upregulated, highlighting distinct regulatory patterns. Gene Ontology (GO) enrichment analysis revealed significant involvement in pathways such as potassium ion import, nitrate response, and transcription regulation. Notably, HSP70 was one of the hyper-upregulated genes in response to cold stress. Fluorescence polarization assays demonstrated that HSP70 binds preferentially to m6A-modified RNAs, suggesting its role in forming protective condensates under cold conditions. This interaction between m6A modification and HSP70 points to a potential mechanism that helps stabilize stress-responsive transcripts, contributing to the plant's enhanced cold tolerance. m6A modifications play a vital role in regulating gene expression under cold stress, offering new insights into mango's stress responses and potential breeding strategies for cold tolerance.