Holtorf H, Schöb H, Kunz C, Waldvogel R, Meins F
Friedrich Miescher Institute, P.O. Box 2543, CH-4002 Basel, Switzerland.
Plant Cell. 1999 Mar;11(3):471-84. doi: 10.1105/tpc.11.3.471.
Stochastic and nonstochastic post-transcriptional gene silencing (PTGS) in Nicotiana sylvestris plants carrying tobacco class I chitinase (CHN) and beta-1,3-glucanase transgenes differs in incidence, stability, and pattern of expression. Measurements with inhibitors of RNA synthesis (cordycepin, actinomycin D, and alpha-amanitin) showed that both forms of PTGS are associated with increased sequence-specific degradation of transcripts, suggesting that increased RNA turnover may be a general feature of PTGS. The protein synthesis inhibitors cycloheximide and verrucarin A did not inhibit degradation of CHN RNA targeted for PTGS, confirming that PTGS-related RNA degradation does not depend on ongoing protein synthesis. Because verrucarin A, unlike cycloheximide, dissociates mRNA from ribosomes, our results also suggest that ribosome-associated RNA degradation pathways may not be involved in CHN PTGS.
携带烟草I类几丁质酶（CHN）和β-1,3-葡聚糖酶转基因的野生烟草植株中的随机和非随机转录后基因沉默（PTGS）在发生率、稳定性和表达模式上存在差异。使用RNA合成抑制剂（虫草素、放线菌素D和α-鹅膏蕈碱）进行的测量表明，两种形式的PTGS均与转录本序列特异性降解增加有关，这表明RNA周转增加可能是PTGS的一个普遍特征。蛋白质合成抑制剂环己酰亚胺和疣孢菌素A并未抑制靶向PTGS的CHN RNA的降解，证实与PTGS相关的RNA降解不依赖于正在进行的蛋白质合成。由于与环己酰亚胺不同，疣孢菌素A会使mRNA与核糖体解离，我们的结果还表明核糖体相关的RNA降解途径可能不参与CHN PTGS。
