Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China.
Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, 91766, USA.
Plant J. 2018 Jan;93(2):246-258. doi: 10.1111/tpj.13771. Epub 2017 Dec 18.
Auxin is widely involved in plant growth and development. However, the molecular mechanism on how auxin carries out this work is unclear. In particular, the effect of auxin on pre-mRNA post-transcriptional regulation is mostly unknown. By using a poly(A) tag (PAT) sequencing approach, mRNA alternative polyadenylation (APA) profiles after auxin treatment were revealed. We showed that hundreds of poly(A) site clusters (PACs) are affected by auxin at the transcriptome level, where auxin reduces PAC distribution in 5'-untranslated region (UTR), but increases in the 3'UTR. APA site usage frequencies of 42 genes were switched by auxin, suggesting that auxin affects the choice of poly(A) sites. Furthermore, poly(A) signal selection was altered after auxin treatment. For example, a mutant of poly(A) signal binding protein CPSF30 showed altered sensitivity to auxin treatment, indicating interactions between auxin and the poly(A) signal recognition machinery. We also found that auxin activity on lateral root development is likely mediated by altered expression of ARF7, ARF19 and IAA14 through poly(A) site switches. Our results shed light on the molecular mechanisms of auxin responses relative to its interactions with mRNA polyadenylation.
生长素广泛参与植物的生长和发育。然而，生长素如何发挥作用的分子机制尚不清楚。特别是生长素对前体 mRNA 转录后调控的影响在很大程度上是未知的。通过使用多聚腺苷酸标签（PAT）测序方法，揭示了生长素处理后 mRNA 可变多聚腺苷酸化（APA）的图谱。我们表明，数百个多聚腺苷酸位点簇（PAC）在转录组水平上受到生长素的影响，生长素降低了 5'非翻译区（UTR）中的 PAC 分布，但增加了 3'UTR 中的分布。生长素改变了 42 个基因的 APA 位点使用频率，表明生长素影响多聚腺苷酸位点的选择。此外，生长素处理后多聚腺苷酸信号的选择发生了改变。例如，多聚腺苷酸信号结合蛋白 CPSF30 的突变体对生长素处理表现出改变的敏感性，表明生长素与多聚腺苷酸信号识别机制之间存在相互作用。我们还发现，生长素对侧根发育的活性可能是通过改变 ARF7、ARF19 和 IAA14 的表达，通过多聚腺苷酸位点的改变来介导的。我们的研究结果阐明了生长素响应的分子机制及其与 mRNA 多聚腺苷酸化的相互作用。
