RNA Editing Analysis Reveals Methyl Jasmonic Acid Regulation of Fucoxanthin and Fatty Acid Metabolism in Phaeodactylum tricornutum

<i>Phaeodactylum tricornutum</i> is a marine diatom with significant biotechnological potential, particularly in producing high-value bioactive compounds such as fucoxanthin and unsaturated fatty acids, which possess significant pharmaceutical and nutraceutical properties. However, the naturally low yields of these compounds present a major challenge for large-scale production. Methyl jasmonic acid (MeJA), a plant-derived signaling molecule, has been shown to enhance the biosynthesis of these metabolites in <i>P. tricornutum</i>. While transcriptional regulation has been extensively studied, the role of post-transcriptional modifications, such as RNA editing, in mediating MeJA-induced metabolic changes remains largely unexplored. RNA editing can alter nucleotide sequences, leading to functional changes in gene expression and protein activity, thus providing a potential regulatory mechanism for enhanced biosynthesis of target metabolites. In this study, we investigated the role of RNA editing in <i>Phaeodactylum tricornutum</i> under methyl jasmonic acid (MeJA) treatment, focusing on its impact on the accumulation of bioactive compounds such as fucoxanthin and fatty acids. We conducted a comprehensive comparative analysis of RNA editing events across MeJA-treated and control groups. Our findings reveal that MeJA treatment induces significant variations in RNA editing levels, affecting key metabolic pathways. Notably, two genes, <i>Lhcr10</i> (<i>Phatr3_J16481</i>) and <i>Phatr3_J43665</i>, were identified as potential contributors to increased RNA editing enzyme activity and to energy metabolism and fatty acid biosynthesis under MeJA treatment. These results provide a foundation for the discovery of molecular mechanisms underlying adaptive responses in <i>P. tricornutum</i> and highlight RNA editing as a critical regulatory mechanism in MeJA-induced metabolic reprogramming.