Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu Province, People's Republic of China.
College of Health Sciences, Jiangsu Normal University, Xuzhou, Jiangsu Province, People's Republic of China.
J Plant Physiol. 2020 Aug;251:153224. doi: 10.1016/j.jplph.2020.153224. Epub 2020 Jul 2.
Sweet potato (Ipomoea batatas L.) is a food consumed worldwide, an industrial raw material and new energy crop. The storage root is the most economical part of the crop. However, the mechanism of storage root initiation and development is still unclear. In this study, conserved and novel miRNAs during storage root development were identified by high-throughput sequencing technology by constructing small RNA libraries from sweet potato fibrous roots (F) and storage roots at four different developmental stages (storage roots with different diameters: 1 cm, D1; 3 cm, D3; 5 cm, D5 and 10 cm, D10). A total of 61 known miRNAs and 471 novel miRNAs were identified. In addition, 145 differentially expressed miRNAs were identified in the F library compared with the four storage root libraries, with 30 known miRNAs and 115 novel miRNAs. Moreover, the targets of the differentially expressed miRNAs were predicted and their network was further investigated by GO analysis using our previous transcriptome data. The GO analysis revealed that antioxidant activity and binding process were the most enriched terms of the target genes. The secondary structure and expression of six candidate miRNAs including three conserved miRNAs and three novel miRNAs were investigated and their predicted targets were validated by qRT-PCR. The results showed that the expression levels of the miRNAs were all consistent with the sequencing data. Most of the miRNAs and their corresponding targets had obvious negative correlations. This study contributed to elucidating the potential miRNA mediated regulatory mechanism of storage root development in sweet potato. The specific differentially expressed miRNAs in sweet potato storage roots can be used to breed high-yield sweet potatoes and other tuberous root crops.
甘薯（Ipomoea batatas L.）是一种在全球范围内食用的食物，是工业原料和新能源作物。块根是作物中最经济的部分。然而，块根起始和发育的机制尚不清楚。本研究通过从小薯纤维根（F）和四个不同发育阶段（直径不同的块根：1cm，D1；3cm，D3；5cm，D5 和 10cm，D10）构建小 RNA 文库，利用高通量测序技术鉴定了块根发育过程中保守和新的 miRNA。共鉴定出 61 个已知 miRNA 和 471 个新 miRNA。此外，与四个块根文库相比，F 文库中鉴定出 145 个差异表达的 miRNA，其中包括 30 个已知 miRNA 和 115 个新 miRNA。此外，利用我们之前的转录组数据进行 GO 分析，预测差异表达 miRNA 的靶基因，并进一步研究其网络。GO 分析表明，抗氧化活性和结合过程是靶基因最富集的术语。对包括三个保守 miRNA 和三个新 miRNA 在内的六个候选 miRNA 的二级结构和表达进行了研究，并通过 qRT-PCR 验证了其预测靶基因。结果表明，miRNA 的表达水平与测序数据一致。大多数 miRNA 及其对应的靶基因具有明显的负相关关系。本研究有助于阐明甘薯块根发育中潜在的 miRNA 介导的调控机制。甘薯块根中特异性差异表达的 miRNA 可用于培育高产甘薯和其他块根作物。
