Key Regulatory Pathways, MicroRNAs, and Target Genes Participate in Adventitious Root Formation of Acer Rubrum L
Abstract BackgroundAcer rubrum L. is a colorful ornamental tree with great economic value. Because this tree is difficult to root under natural conditions and the seedling survival rate is low, vegetative propagation methods are often used. Because the formation of adventitious roots (ARs) is essential for the survival of asexual propagation of A. rubrum, it is necessary to investigate the molecular regulatory mechanisms in the formation of ARs of A. ruburm. To address this knowledge gap, we sequenced the transcriptome and sRNA of the A. rubrum variety ‘Autumn Fantasy’ using high-throughput sequencing and explored changes in gene and microRNA (miRNA) expression in response to exogenous auxin treatment. ResultsWe identified 82,468 differentially expressed genes between the treated and untreated ARs, as well as 48 known and 95 novel miRNAs. We also identified 172 target genes of the known miRNAs using degradome sequencing. Two regulatory pathways (ubiquitin mediated proteolysis and plant hormone signal transduction), Ar-miR160a and the target gene ArARF10 were shown to be involved in the auxin response. We further investigated the expression patterns and regulatory roles of ArARF10 through subcellular localization, transcriptional activation, plant transformation, qRT-PCR analysis, and GUS staining. ConclusionsDifferential expression patterns indicated the Ar-miR160a-ArARF10 interaction might play a significant role in the regulation of AR formation in A. rubrum. Our study provided new insights into mechanisms underlying the regulation of AR formation in A. rubrum.