木薯 sRNA 测序分析及其开花相关 microRNA 的挖掘

为研究木薯花序与叶片中 sRNA 表达特性，探索 microRNA 对其开花过程的调控。本研究以木薯品种“华南 八号”花序和幼叶为材料，利用 RNA-seq 技术进行 sRNA 测序分析；并筛选开花相关 microRNAs 进行表达特性分析。 从花序和幼叶测序结果中分别获得 12 092 109 条和 11 499 655 条 sRNA 序列。花序中筛选出 139 条已知 microRNAs 和 253 条新预测 microRNA，分别预测得到 992 和 3 736 条靶基因；幼叶中筛选出 134 条已知 microRNA 和 191 条新预测 microRNAs，分别预测得到 979 和 2 603 条靶基因。最终筛选出 8 种与开花调控相关和 3 种花色调控相关的 microRNAs。 表达分析显示，miRNAs 在两样品间呈现出较大的整体性差异，并且在功能与代谢通路上也不尽相同；开花相关 microRNAs 中表达差异较大的为 miR156、miR172 和 miR169，其中 miR156 表达量在花序中高于幼叶，而 miR172 表 达量在花序中低于幼叶，推测其功能为抑制后续的开花过程，避免过度开花。本研究分析了木薯花序与幼叶中 sRNA 的整体特性，通过表达差异分析初步明确了 microRNAs 对木薯开花的调控，为进一步深入探索奠定了基础。

Analysis of sRNA Sequencing and Mining of Flowering-related microRNA in Manihot esculenta Crantz

To study the expression characteristics of sRNA between inflorescence and young leaf in Manihot esculenta Crantz, and to explore regulation function of microRNAs during flowering process. This study performed sRNA sequencing by RNA-seq technique with “SC8” inflorescence and young leaf as material, meanwhile, the flowering-related microRNAs were screened for expression characteristic analysis. 12 092 109 and 11 499 655 sRNA reads were obtained from inflorescence and young leaf samples by sequencing. Then 139 known and 253 novel microRNAs were screened from inflorescence sample, and target prediction produced 992 and 3 736 target genes respectively. Likewise, 134 known and 191 novel microRNAs were screened in young leaf sample, 979 and 2 603 target genes were predicted. Moreover, 8 flowering-related microRNA family and 3 flower color regulation microRNAs family were identified. Expression analysis showed that microRNAs between two samples expressed differentially as a whole, and their functions and metabolic pathways were also not the same. Among them, expression level of miR156, miR172 and miR169 between two samples were different significantly. Especially, miR156 expression were up-regulated and miR172 expression were down-regulated in inflorescence than young leaf, these characteristics suggest that their function might be the inhibition of subsequent flowering process and avoid excessive bloom. The present study provides the first large-scale characterization of sRNA in inflorescence and young leaf and the flowering related microRNAs comparison between them gives an insight into how microRNA are involve in flowering regulation and lays a foundation for further research.