Identification of microRNAs involved in betalain metabolism in the green and red sectors of amaranth leaves based on Illumina sequencing data

Amaranth plants are rich in betalains. Additionally, the molecular structure and metabolic pathway of betalains are different in amaranth than in beet. To date, only a few studies have examined the regulatory roles of microRNAs (miRNAs) in betalain biosynthesis in plants. Thus, we constructed small RNA libraries for the red and green sectors of amaranth leaves to identify miRNAs associated with betalain biosynthesis. We identified 239 miRNAs including 198 known and 41 novel miRNAs. 493 target genes for the 239 miRNAs were detected in an amaranth transcriptome database. The validation of the expression of 20 miRNAs and nine target genes in a quantitative real-time polymerase chain reaction assay revealed the miRNAs and target genes that were differentially expressed in the two leaf sectors. The miRNAs involved in betalain metabolism in amaranth plants were identified by Illumina sequencing platform. The data presented herein may provide insights into the regulation molecular mechanisms for betalain biosynthesis in amaranth and other plant species.

苋属植物富含甜菜红素（betalains）。此外，苋属植物中甜菜红素的分子结构与代谢通路与甜菜中的存在差异。截至目前，仅有少数研究探讨了微RNA（microRNAs，miRNAs）在植物甜菜红素生物合成中的调控作用。因此，本研究针对苋属植物叶片的红色与绿色区域构建了小RNA文库，以筛选与甜菜红素生物合成相关的miRNAs。本研究共鉴定得到239个miRNAs，其中包含198个已知miRNA与41个新发现miRNA。在苋属植物转录组数据库中，共检测到对应这239个miRNAs的493个靶基因。本研究通过实时荧光定量聚合酶链反应（quantitative real-time polymerase chain reaction）实验对20个miRNAs与9个靶基因的表达进行验证，筛选得到在两类叶片区域中差异表达的miRNAs与靶基因。本研究依托Illumina测序平台，成功鉴定得到苋属植物中参与甜菜红素代谢的miRNAs。本研究所得数据可为苋属植物及其他植物物种中甜菜红素生物合成的分子调控机制研究提供新的见解。