GSE193522
Comparative Transcriptome Analysis Uncovers the Regulatory Functions of MicroRNAs in Flower Development and Color Changes of Pink-flowered Strawberry
The pink-flowered strawberry is very popular in China due to its appreciation and economic benefits and its flower has rich red petal with varying degrees, which is provided by anthocyanins accumulation. To better understand the functions of miRNAs, sRNAome, transcriptome and degradome sequencing were used to explore the target genes of miRNAs in flower development and coloring of pink-flowered strawberry. Nine small RNA libraries and a mixed degradome library from flower petals at different developmental stages were constructed and sequenced in this study. A total of 739 known miRNAs and 964 newly identified miRNAs were identified via small RNA sequencing, and their 2816 target genes were cleaved by 639 miRNAs based on the degradome data. There were 317 different expression miRNAs among flower development in pink-flowered strawberry regulated 2134 different expression target genes, which significantly enriched in the transcriptional regulation, phenylpropanoid biosynthesis and plant hormone signal transduction. Furthermore, integrated microRNAomic and transcriptomic analyses suggested that 98 miRNAs were targeted several transcription factors related to anthocyanin accumulation, in which 26 were targeted to MYBs, 12 bHLHs, 14 NACs, and 19 SPLs. And that, twenty seven different expression miRNAs may affect anthocyanin biosynthesis by regulating 23 targets participated in hormone signal transduction pathway in pink-flowered strawberry. The qRT-PCR analysis confirmed the expression changes of 21 miRNA-target pairs showed an opposite trend. Moreover, a co-expression regulatory network was constructed based on differentially expressed miRNA-targets according to the degradome data. Overall, we conducted a comparative analysis uncovered the regulatory functions of microRNAs in flower development and color changes of pink-flowered strawberry via multiple factors, including anthocyanin biosynthesis, hormone signaling and regulation factors. This work not only expands the knowledge of miRNAs affecting the coloration in strawberry, but also provides rich resources for future functional studies. Overall design: Petals of three developmental stages with obviously different color ('L', 'Z' and 'D') were selected for miRNAsanalysis and three biological repetitions were set for each treatment.