Title : Post-transcriptional regulation of abiotic stress response by EGRBP42 in oil palm
Abstract:
Abiotic stress is a significant limiting factor for plant growth and crop productivity. Understanding the molecular mechanisms that govern stress responses is critical for developing resilient crop varieties. In oil palm, we identified a heterogeneous nuclear ribonucleoprotein (hnRNP)-like RNA-binding protein, EgRBP42 as a key regulator mediating the post-transcriptional nucleocytoplasmic RNA transport of stress-responsive transcripts in response to environmental stress. Overexpression of EgRBP42 in Arabidopsis thaliana conferred enhanced tolerance to multiple abiotic stresses, including drought, salinity, heat, cold, and submergence. This resulted in improved physiological performance, enhanced post-stress recovery response and accelerated flowering, linked to the modulation of flowering regulator gene expression. Our study revealed that EgRBP42 possesses nucleocytoplasmic shuttling ability via a nuclear localization signal and an M9-like domain and interacts directly with regulator proteins in the nucleus, membrane, and the cytoplasm. EgRBP42 binds directly to the AG-rich motifs in its downstream target stress-responsive transcripts, promoting their nucleocytoplasmic transport and translation during stress response. Furthermore, the oil palm stable transgenic lines overexpressing EgRBP42 exhibited enhanced stress resilience under controlled abiotic stress treatments, further confirming EgRBP42’s role in enhancing stress adaptation in oil palm. Building on these findings, current work focuses on DNA-free genome editing of EgRBP42 regulatory elements in oil palm to enhance stress responsiveness while maintaining yield performance under climate variability. These findings suggest that EgRBP42 plays a key role in modulating transcript availability during stress, leading to better stress adaptation in plants and serves as a potential target for developing climate-resilient oil palm through precision breeding approaches.
