Deng Kexuan, Yin Huan, Xiong Fangjie, Feng Li, Dong Pan, Ren Maozhi
School of Life Sciences, Chongqing University, Chongqing, China.
Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China.
PeerJ. 2021 Jan 14;9:e10704. doi: 10.7717/peerj.10704. eCollection 2021.
Target of rapamycin (TOR) operates as a hub of the signal transduction that integrates nutrient and energy signaling to promote cell proliferation and growth through mediating the transcriptional and post- transcriptional regulator networks in all eukaryotic species. MicroRNAs (miRNAs) are widespread classes of small, single-stranded, non-coding endogenous RNAs and are widely found in eukaryotes, which play a vital role in regulating gene expression by degrading targeted mRNAs or translational repression at post-transcriptional level. Recent studies found that there were necessarily close connections between miRNA and TOR pathways in mammals. However, there is little information about the interplay between the miRNA and TOR in plants. Thus, the aim of this study was to identify potential TOR-miRNA-mRNA regulatory networks in TOR signaling through global mRNA and microRNA expression profiling in potato. Based on the previous high-throughput transcriptome sequencing and filtering, a total of 2,899 genes were significantly differentially expressed in potato under TOR inhibitors treatment. Pathway analysis revealed that these genes were significantly enriched in multiple metabolic processes. Similarly, in the present study, suppression of TOR resulted in 41 miRNAs up-regulated and 45 down-regulated, revealing that TOR plays a crucial role in the regulation of miRNA regulatory network. Furthermore, integrated mRNA and miRNA expression profiling uncovered that these miRNAs participated in large-scale metabolic process in the TOR signal pathway in potato, such as regulation of autophagy and ubiquitination, and biosynthesis of secondary metabolites. Overall, the results shed new insight into TOR related post-transcriptional gene regulatory networks in potato and suggesting TOR-miRNA-targeting genes relevant networks as a potential genetic resource for potato improvement.
雷帕霉素靶蛋白（TOR）作为信号转导的枢纽，通过介导所有真核生物物种中的转录和转录后调节网络，整合营养和能量信号以促进细胞增殖和生长。微小RNA（miRNA）是广泛存在的一类小的单链非编码内源性RNA，在真核生物中广泛存在，它们通过在转录后水平降解靶向mRNA或抑制翻译来调节基因表达，发挥着至关重要的作用。最近的研究发现，在哺乳动物中miRNA与TOR信号通路之间必然存在密切联系。然而，关于植物中miRNA与TOR之间的相互作用的信息却很少。因此，本研究的目的是通过对马铃薯中全局mRNA和微小RNA表达谱分析，确定TOR信号通路中潜在的TOR-miRNA-mRNA调控网络。基于先前的高通量转录组测序和筛选，在TOR抑制剂处理下，马铃薯共有2899个基因显著差异表达。通路分析表明，这些基因在多个代谢过程中显著富集。同样，在本研究中，TOR的抑制导致41个miRNA上调，45个下调，表明TOR在miRNA调控网络的调节中起关键作用。此外，整合的mRNA和miRNA表达谱揭示，这些miRNA参与了马铃薯TOR信号通路中的大规模代谢过程，如自噬和泛素化的调节以及次生代谢物的生物合成。总体而言，这些结果为马铃薯中与TOR相关的转录后基因调控网络提供了新的见解，并表明TOR-miRNA靶向基因相关网络作为马铃薯改良的潜在遗传资源。
