mRNA Decay Mediates Evolution and Biological Functions in Plant Gene Expression

mRNA decay is a key post-transcriptional regulatory mechanism that fine-tunes plant development and stress adaptation through dynamic mRNA stability control, bridging fundamental biology and crop improvement. Current knowledge of mRNA decay mechanisms in plants, largely derived from Arabidopsis, is poorly generalisable across plant lineages owing to insufficient exploration of other species. Recent advances in high-throughput sequencing have accelerated the discovery of mRNA decay mechanisms. Here, we systematically illustrate its core molecular mechanisms alongside breakthrough advances. We further dissect evolutionary characteristics of highly conserved core components and lineage-specific adaptive variations across eukaryotes. Notably, conserved since the last eukaryotic common ancestor (LECA), this machinery reflects a complex ancestral eukaryote and provides high-resolution phylogenetic markers for reconstructing eukaryotic origins. We also clarify the essential biological roles of mRNA decay in developmental modulation and stress responses. Finally, we propose precision breeding strategies based on mRNA stability regulation to develop high-yielding, climate-resilient crops. This review integrates up-to-date mechanistic evidence and comparative evolutionary perspectives, consolidates consensus findings and sorts out inconsistent research outcomes, and seeks to enrich the fundamental biological understanding of plant mRNA stability modulation.