Key Laboratory for Silviculture and Conservation, Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, People's Republic of China.
PLoS One. 2012;7(9):e44968. doi: 10.1371/journal.pone.0044968. Epub 2012 Sep 18.
MicroRNAs (miRNAs), a type of short (21-23 nucleotides), non-coding RNA molecule, mediate repressive gene regulation through RNA silencing at the post-transcriptional level, and play an important role in defense and response to abiotic and biotic stresses. In the present study, Affymetrix® miRNA Array, real-time quantitative PCR (qPCR) for miRNAs and their targets, and miRNA promoter analysis were used to validate the gene expression patterns of miRNAs in Populus trichocarpa plantlets induced with the poplar stem canker pathogen, Botryosphaeria dothidea. Twelve miRNAs (miR156, miR159, miR160, miR164, miR166, miR168, miR172, miR319, miR398, miR408, miR1448, and miR1450) were upregulated in the stem bark of P. trichocarpa, but no downregulated miRNAs were found. Based on analysis of the miRNAs and their targets, a potential co-regulatory network was developed to describe post-transcriptional regulation in the pathological development of poplar stem canker. There was highly complex cross-talk between diverse miRNA pathway responses to biotic and abiotic stresses. The results suggest that miR156 is probably an integral component of the miRNA response to all environmental stresses in plants. Cis-regulatory elements were binding sites for the transcription factors (TFs) on DNA. Promoter analysis revealed that TC-rich repeats and a W1-box motif were both tightly related disease response motifs in Populus. Promoter analysis and target analysis of miRNAs also revealed that some TFs regulate their activation/repression. Furthermore, a feedback regulatory network in the pathological development of poplar stem canker is provided. The results confirm that miRNA pathways regulate gene expression during the pathological development of plant disease, and provide new insights into understanding the onset and development of poplar stem canker.
MicroRNAs (miRNAs) 是一种短（21-23 个核苷酸）的非编码 RNA 分子，通过 RNA 沉默在转录后水平介导抑制性基因调控，在防御和应对非生物和生物胁迫方面发挥着重要作用。在本研究中，使用 Affymetrix® miRNA 阵列、miRNA 及其靶标实时定量 PCR(qPCR) 和 miRNA 启动子分析来验证杨树溃疡病菌 Botryosphaeria dothidea 诱导的杨树苗中 miRNA 的基因表达模式。在杨树苗的树皮中，上调了 12 个 miRNA（miR156、miR159、miR160、miR164、miR166、miR168、miR172、miR319、miR398、miR408、miR1448 和 miR1450），但未发现下调的 miRNA。基于 miRNA 和它们的靶标分析，开发了一个潜在的共调控网络，以描述杨树溃疡病病理发育中的转录后调控。不同 miRNA 途径对生物和非生物胁迫的反应之间存在高度复杂的交叉对话。结果表明，miR156 可能是植物对所有环境胁迫的 miRNA 反应的一个组成部分。顺式调控元件是 DNA 上转录因子 (TFs) 的结合位点。启动子分析表明，TC 丰富重复和 W1 盒基序都是杨树中紧密相关的疾病反应基序。miRNA 的启动子分析和靶标分析也表明，一些 TFs 调节它们的激活/抑制。此外，还提供了杨树溃疡病病理发育的反馈调控网络。结果证实 miRNA 途径在植物病害的病理发育过程中调节基因表达，为理解杨树溃疡病的发生和发展提供了新的见解。
