Persicaria minor F-box protein, PmFBK2 targeted by miR156a in response to MeJA treatment, potentially affects stress-related proteins

This study investigates the relationship between microRNAs (miRNAs) and F-box proteins (FBPs) in Persicaria minor, under methyl jasmonate (MeJA) treatment. miRNAs regulate gene expression by targeting mRNAs via cleaving or modifying the mRNAs through base pairing, while FBPs, as part of the SCF (Skp1-Cullin-F-box) complex, mediates protein degradation via the ubiquitin-26S proteasome system (UPS). These post-transcriptional and post-translational regulators work together to activate plant responses. Integrated in silico analysis and experimental validation identified five miRNA–FBP pairs: miR156a–PmFBK2, miR396a–PmFBX1, miR156a/c–PmFBX2, miR408–PmFBK3, and miR398–PmFBL1. Among these, miR156a and miR408 showed negative expression correlations with their FBP targets, further confirmed by RLM-RACE cleavage assays, suggesting direct post-transcriptional regulation. Both target genes encode FBP containing kelch repeat (FBK), a subfamily abundant in plants and associated with stress-responsive pathways. Further analysis of the miR156a target through yeast two-hybrid (Y2H) revealed that, PmFBK2 protein targets SAMS2, PAL1 and GID1, proteins involved in metabolic and hormonal regulation linked to stress responses These findings suggest that miRNA-mediated regulation of FBP may influence protein interaction networks relevant to stress adaptation. This study presents foundational evidence for the involvement of specific miRNA-FBP interactions in plant stress responses, laying the groundwork for future functional validation and crop improvement.