School of Life Sciences, University of Nevada Las Vegas, 4505 South Maryland Parkway, Las Vegas, NV, 89154, USA.
Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.
Plant Cell Environ. 2017 Sep;40(9):2004-2016. doi: 10.1111/pce.13006. Epub 2017 Jul 18.
Seeds serve as a great model to study plant responses to drought stress, which is largely mediated by abscisic acid (ABA). The ABA responsive element (ABRE) is a key cis-regulatory element in ABA signalling. However, its consensus sequence (ACGTG(G/T)C) is present in the promoters of only about 40% of ABA-induced genes in rice aleurone cells, suggesting other ABREs may exist. To identify novel ABREs, RNA sequencing was performed on aleurone cells of rice seeds treated with 20 μM ABA. Gibbs sampling was used to identify enriched elements, and particle bombardment-mediated transient expression studies were performed to verify the function. Gene ontology analysis was performed to predict the roles of genes containing the novel ABREs. This study revealed 2443 ABA-inducible genes and a novel ABRE, designated as ABREN, which was experimentally verified to mediate ABA signalling in rice aleurone cells. Many of the ABREN-containing genes are predicted to be involved in stress responses and transcription. Analysis of other species suggests that the ABREN may be monocot specific. This study also revealed interesting expression patterns of genes involved in ABA metabolism and signalling. Collectively, this study advanced our understanding of diverse cis-regulatory sequences and the transcriptomes underlying ABA responses in rice aleurone cells.
种子是研究植物对干旱胁迫反应的理想模型，这种反应在很大程度上是由脱落酸（ABA）介导的。ABA 响应元件（ABRE）是 ABA 信号转导中的关键顺式调控元件。然而，在水稻糊粉层细胞中，ABA 诱导的基因启动子中只有约 40%存在其保守序列（ACGTG(G/T)C），这表明可能存在其他 ABRE。为了鉴定新的 ABRE，对用 20 μM ABA 处理的水稻种子糊粉层细胞进行了 RNA 测序。使用 Gibbs 抽样来识别富集元件，并进行粒子轰击介导的瞬时表达研究来验证功能。进行了基因本体分析以预测含有新 ABRE 的基因的作用。这项研究揭示了 2443 个 ABA 诱导基因和一个新的 ABRE，命名为 ABREN，实验验证了其在水稻糊粉层细胞中介导 ABA 信号转导的功能。许多含有 ABREN 的基因被预测参与应激反应和转录。对其他物种的分析表明，ABREN 可能是单子叶植物所特有的。这项研究还揭示了与 ABA 代谢和信号转导相关的基因的有趣表达模式。总的来说，这项研究增进了我们对水稻糊粉层细胞中 ABA 反应的不同顺式调控序列和转录组的理解。
