Identification, characterization, and functional analysis of the miR160 family in moso bamboo (Phyllostachys edulis)

Abstract

The rapid growth of Phyllostachys edulis is intimately linked to auxin signaling. While miR160 has been shown to modulate this pathway through targeting ARF transcription factors, its functional implications in moso bamboo await comprehensive investigation. In this study, we systematically identified members of the miR160 gene family in moso bamboo. A total of 10 precursor sequences and 15 mature sequences were found, and all of the precursors were able to form stable stem‒loop structures (minimum free energy of folding −57.00 to −38.30 kcal/mol). Multiple sequence alignment and phylogenetic analysis confirmed that this family is highly conserved and is closely related to rice miR160. Target gene prediction revealed that miR160 may act on growth factor response factors such as PheARF22 and PheARF13. The cis-acting element of the miR160 promoter was also predicted, and experimental validation revealed that miR160g could specifically cleave target genes. The tissue specificity of miR160 family gene expression was also verified by RT‒qPCR and RNA FISH. Transcriptome analysis of transgenic rice identified 1470 differentially expressed genes (DEGs). GO and KEGG enrichment analyses revealed that miR160 silencing significantly affected plant hormone signaling and secondary metabolic pathways. Subsequent quantification of endogenous auxin (IAA) demonstrated a substantial increase in transgenic plants, providing compelling evidence that miR160 modulates auxin signaling pathways through ARF regulation. These findings offer novel molecular insights into the rapid growth mechanisms of bamboo species.