Tamarisk miRNA target genes TcSPL5 and TcNAC1 mediate the post-transcriptional responses of salt stress

Tamarix chinensis, a pioneer species on saline-alkali soils, provides an excellent model for studying crop salt tolerance. Here we identified 22 salt-responsive miRNAs and one phase siRNA locus in T. chinensis roots exposed to NaCl. Expression profiling combined with the dual-luciferase reporter assays revealed a negatively correlated regulatory module, miR164-TcNAC1, which, alongside the previously reported miR156-TcSPL5 module, likely contributes to post-transcriptional responses during salt stress. Arabidopsis plants overexpressing miRNA-resistant forms of TcNAC1 and TcSPL5 exhibited markedly increased salt sensitivity: seed germination, root growth and leaf development were significantly impaired under salt treatment and were associated with elevated lipid peroxidation. Collectively, our results identify tamarisk miRNA-targeted regulators involved in salt tolerance and advance understanding of post-transcriptional control mechanisms under saline stress, with potential implications for improving crop salt tolerance.