Post-Transcriptional Fine-Tuning of Woody Leaf Senescence: From Alternative Splicing to Epitranscriptomic Modifications

Leaf senescence in perennial deciduous trees is a coordinated process linked to seasonal nutrient recycling, crucial for longevity and adaptation. Beyond transcriptional regulation, post-transcriptional mechanisms rapidly fine-tune gene expression and expand transcriptomic diversity. This review synthesizes emerging post-transcriptional regulatory networks governing woody plant leaf senescence. We highlight alternative splicing as a molecular switch, exemplified by PtRD26IR, an anti-aging variant that functions via dominant-negative inhibition of senescence-associated NACs. Additionally, we detail non-coding RNA (ncRNA) networks—including conserved miR164-NAC modules, miR390-tasiRNA-ARF cascades, and lncRNA/circRNA-mediated ceRNA sponging—that integrate hormonal and stress cues. We further explore epitranscriptomic dynamics (m6A, m1A, m5C) regulating mRNA stability and translation in leaf-color variants, along with PPR protein-mediated organellar RNA editing that preserves chloroplast and mitochondrial integrity during decline. Integrating these multi-layered pathways establishes a comprehensive framework for forest longevity and offers precision molecular targets for stress-tolerant, high-yield tree breeding.