Genome-wide identifcation of transcripts and miRNAs during somatic embryogenesis in Pinellia ternata

Pinellia ternata (Thunb.) Breit, a well-known Chinese medicinal plants, is mainly produced by clonal propagation. Somatic embryogenesis (SEG) is a major process for plant regeneration, however, the molecular mechanism of SEG in P. ternata is still unclear. In this study, genome-wide mRNAs and small RNAs analysis were performed on the samples from three key stages of P. ternata SEG, including explant, calli and protocorm‐like bodies. The results showed that the increase in the content of auxins, I3CA and ICA1, contributed to the regeneration of P. ternata; PtAUX/IAA2, PtSAUR1, PtAEC1, PtAEC2, PtAUT1 and PtAUT2 were important regulatory genes for auxins action; AP2/ERFs and other 35 TFs were important components of the regenerative regulation network of P. ternata. Among the 1368 miRNAs identified in this study, miR396 were the key miRNAs involved in regulating P. ternata SEG.三叶半夏（Pinellia ternata (Thunb.) Breit）是一味知名中药材，主要以无性繁殖方式进行繁殖。体细胞胚胎发生（somatic embryogenesis, SEG）是植物再生的关键途径之一，但目前三叶半夏中SEG的分子调控机制尚未阐明。本研究针对三叶半夏SEG过程中的三个关键阶段（外植体、愈伤组织与原球茎样体）的样本，开展了全基因组范围的mRNA与小RNA组分析。研究结果显示，生长素类物质I3CA与ICA1的含量升高，可促进三叶半夏的再生过程；PtAUX/IAA2、PtSAUR1、PtAEC1、PtAEC2、PtAUT1及PtAUT2是调控生长素信号通路的关键基因；AP2/ERF转录因子家族（AP2/ERFs）及另外35个转录因子（TFs）是三叶半夏再生调控网络的重要组成部分。本研究共鉴定得到1368个微小RNA（miRNAs），其中miR396是调控三叶半夏SEG过程的核心微小RNA。