A New Conditional Gene Regulation System in Plants

开启和关闭基因表达的能力是生物体对内部和外部暗示做出反应的能力的关键因素。植物的固持性质意味着需要能够对不断变化的环境条件做出快速反应，这一点尤为重要。直到最近，人们还认为基因调控的主要途径发生在转录之前。然而，现在已经知道，转录后过程在调节基因表达方面起着至关重要的作用。在这些过程中，有一项就是控制mRNA的稳定性。虽然miRNAs对mRNA稳定性的调控已经在植物中得到了很好的探索，并继续为植物的生长发育提供新的见解，但对其他形式的mRNA稳定性控制却知之甚少。一些信使核糖核酸转录本基于诱导无义介导信使核糖核酸衰变(NMD)的固有特征而被特定地作为降解的靶标。NMD调节大量真核转录本的稳定性(在一系列物种中约为10%)，通过将转录本移入或移出NMD的影响，细胞能够对紧急信号做出快速反应。我们最近发现，一个高度保守的信号(保守的上游肽开放阅读框架-CPuORF)针对特定的mRNAs，供NMD破坏。我们的证据表明，这种情况的发生是有条件的，是对一系列信号的反应，包括非生物胁迫、特定小分子的存在以及翻译效率的变化。作为工业合作伙伴奖的一部分，我们与拜耳作物科学一起寻求支持，以研究这种转录后基因表达调控的新形式，并确定其在作物改良方面的潜力。

The ability to switch gene expression on and off is a critical factor in an organism's capacity to respond to internal and external cues. The sessile nature of plants means that the need to be able to respond rapidly to ever changing environmental conditions is of particular importance. Until recently, it was thought that the major pathways of gene regulation occurred before transcription. However, it is now known that post-transcriptional processes play a crucial role in regulating gene expression. Among these processes is the control of mRNA stability. Whereas the regulation of mRNA stability by miRNAs has been well explored in plants and continues to provide new insights into plant growth and development, other forms of mRNA stability control are less well understood. Some mRNA transcripts are specifically targeted for degradation based on inherent features that induce a process known as nonsense-mediated mRNA decay (NMD). NMD regulates the stability of a large number of eukaryotic transcripts (of the order of 10% in a range of species), and by moving transcripts into or out of the influence of NMD a cell is able to respond quickly to urgent signals. We have recently discovered that a highly conserved signal (the Conserved Peptide upstream Open Reading Frame - CPuORF) targets specific mRNAs for destruction by NMD. Our evidence suggests that this happens conditionally, in response to a range of signals including abiotic stress, the presence of specific small molecules and in response to changes in translational efficiency. Together with Bayer CropScience, as part of an Industrial partnership Award, we seek support to investigate this novel form of posttranscriptional regulation of gene expression and to determine its potential for crop improvement.