Integrated transcriptome and miRNA analysis provides insight into the floral buds dormancy in Prunus armeniaca

Dormancy is a mechanism for perennial trees to resist unfavourable environmental conditions. However, the molecular mechanisms underlying dormancy in apricots have not been fully characterized. Here, we investigated the content of the abscisic acid (ABA) in floral buds, which exhibited a decreasing trend from paradormancy to ecodormancy stages (D1–D3). Combining mRNA and miRNA analyses, 1458 miRNAs corresponding to 28,501 target genes were identified at three stages. The results of DEGs and DE miRNAs showed that 38 DEGs and 10 DE miRNAs responded to low temperatures and short photoperiods were found involved in maintaining the dormancy, and four genes (PaNCED2, PaCYP707A4.1, PaPYL, and PaABF1) and miR5776-x involved in ABA biosynthesis and signaling pathways. Based on weighted gene co-expression network analysis (WGCNA), PaABF1 was identified as the key factor maintaining the dormancy. The findings provide new molecular mechanisms for further research of regulation of dormancy in apricot.