Zhang Junhong, Lin Yan, Wu Fangmin, Zhang Yuting, Cheng Longjun, Huang Menghui, Tong Zaikang
State Key Laboratory of Subtropical Silviculture, School of Forestry and Bio-Technology, Zhejiang A&F University, Hangzhou, China.
Front Genet. 2021 Jan 28;12:552454. doi: 10.3389/fgene.2021.552454. eCollection 2021.
Inorganic phosphate (Pi) is often lacking in natural and agro-climatic environments, which impedes the growth of economically important woody species. Plants have developed strategies to cope with low Pi (LP) availability. MicroRNAs (miRNAs) play important roles in responses to abiotic stresses, including nutrition stress, by regulating target gene expression. However, the miRNA-mediated regulation of these adaptive responses and their underlying coordinating signals are still poorly understood in forestry trees such as . Transcriptomic libraries, small RNA (sRNA) libraries, and a mixed degradome cDNA library of roots and shoots treated under LP and normal conditions (CK) were constructed and sequenced using next-generation deep sequencing. A comprehensive . transcriptome derived from its roots and shoots was constructed, and a total of 76,899 unigenes were generated. Analysis of the transcriptome identified 8,095 and 5,584 differentially expressed genes in roots and shoots, respectively, under LP conditions. sRNA sequencing analyses indicated that 66 and 60 miRNAs were differentially expressed in roots and shoots, respectively, under LP conditions. A total of 109 and 112 miRNA-target pairs were further validated in the roots and shoots, respectively, using degradome sequencing. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis of differential miRNA targets indicated that the "ascorbate and aldarate metabolism" pathway responded to LP, suggesting miRNA-target pairs might participating in the removing of reactive oxidative species under LP stress. Moreover, a putative network of miRNA-target interactions involved in responses to LP stress in is proposed. Taken together, these findings provide useful information to decipher miRNA functions and establish a framework for exploring P signaling networks regulated by miRNAs in and other woody plants. It may provide new insights into the genetic engineering of high use efficiency of Pi in forestry trees.
无机磷酸盐（Pi）在自然和农业气候环境中常常缺乏，这阻碍了具有经济重要性的木本植物的生长。植物已经发展出应对低磷（LP）有效性的策略。微小RNA（miRNA）通过调节靶基因表达在对包括营养胁迫在内的非生物胁迫的响应中发挥重要作用。然而，在诸如[具体树种未给出]等林木中，miRNA介导的对这些适应性反应及其潜在协调信号的调控仍知之甚少。构建了在LP和正常条件（CK）下处理的根和芽的转录组文库、小RNA（sRNA）文库以及混合降解组cDNA文库，并使用下一代深度测序进行测序。构建了源自其根和芽的综合转录组，共产生了76,899个单基因。转录组分析确定在LP条件下，根和芽中分别有8,095个和5,584个差异表达基因。sRNA测序分析表明，在LP条件下，根和芽中分别有66个和60个miRNA差异表达。使用降解组测序分别在根和芽中进一步验证了总共109个和112个miRNA-靶标对。对差异miRNA靶标的京都基因与基因组百科全书通路富集分析表明，“抗坏血酸和醛糖代谢”通路对LP有响应，表明miRNA-靶标对可能参与LP胁迫下活性氧的清除。此外，提出了一个参与[具体树种未给出]对LP胁迫响应的miRNA-靶标相互作用的假定网络。综上所述，这些发现为解读miRNA功能提供了有用信息，并为探索[具体树种未给出]和其他木本植物中由miRNA调控的磷信号网络建立了框架。它可能为林木中磷高利用效率的基因工程提供新的见解。
