Unravelling post-transcriptional mechanisms governing the plant's response to high temperature

气温上升是对粮食安全的重大威胁。最佳温度每升高1摄氏度，英国两种主要作物小麦和大麦的产量就会减少5- 6%。因此，了解植物对温度的感知和反应对于找到克服这些对作物产量的负面影响的方法至关重要。本项目旨在揭示植物对温度环境反应的分子机制。它研究了翻译-蛋白质合成的过程-如何以温度依赖的方式进行调节，以及这如何帮助植物适应其周围环境的生长。信使RNA（mRNA）为翻译过程提供必要的指令。这些分子包含一个编码序列，该序列指定了组装特定蛋白质所需的氨基酸序列，从而起到翻译“蓝图”的作用。一些mRNA分子含有一个或多个短编码序列-所谓的上游开放阅读框架（uORF）-定义主要蛋白质产物的主要编码序列的上游。这些uORFs可以具有调控功能，控制下游序列的翻译。在模式植物拟南芥中，我们发现几种转录本中的uORFs主要在高温下翻译，这提高了这些特征是植物温度响应的主要调节因子的可能性。通过拟议的项目，我们的目标是揭示这些温度敏感的uORF的功能，并全面了解环境温度如何影响翻译起始，这是蛋白质合成的第一步和限速步骤。为了做到这一点，我们将：（1）表征具有突变的uORF序列的mRNA，以揭示温度敏感性uORF在植物温度响应中的作用。(2)研究RNA结构在不同温度下是否影响uORF功能，从而确定这两个特征之间的功能关系。(3)生成一个全球性的、高分辨率的翻译起始数据集，以最高精度跟踪温度对uORF和主要ORF起始速率的影响。这项研究将为我们提供一个系统水平的理解，了解植物如何根据温度环境调整翻译过程。它将使我们能够更好地预测植物将如何科普未来可能遇到的挑战性温度，并最终有助于创造出能够在气候变化中保持高产的作物。

Rising temperatures represent a major threat to food security. For each 1 degree C increase above optimal temperature, the yield of the two UK staple crops wheat and barley is reduced by 5-6%. Understanding how plants sense and respond to temperature is therefore vital to find ways to overcome these negative effects on crop yield.This project seeks to reveal the molecular mechanisms by which plants react to their temperature environment. It investigates how translation - the process by which proteins are synthesised - is regulated in a temperature-dependent manner and how this helps tailor a plant's growth to its surroundings. Messenger RNAs (mRNAs) provide essential instructions for the translation process. These molecules contain a coding sequence that specifies the sequence of amino acids required to assemble a specific protein and thereby function as "blueprints" for translation. Some mRNA molecules contain one or more short coding sequences - so-called upstream open reading frames (uORFs) - upstream of the main coding sequence that defines the major protein product. These uORFs can have regulatory function, controlling translation of the downstream sequence.In the model plant Arabidopsis, we find that uORFs in several transcripts are mainly translated at high temperature, raising the possibility that these features are major regulators of the plant's temperature response. With the proposed project, we aim to uncover the function of these temperature-sensitive uORFs and to gain comprehensive insight into how ambient temperature affects translation initiation, the first and rate-limiting step in protein synthesis. In order to do this, we will:(1) Characterise mRNAs with mutated uORF sequences to reveal a role for temperature-sensitive uORFs in plant temperature responses.(2) Investigate whether RNA structure affects uORF function at different temperatures and thereby define the functional relationship between these two features.(3) Generate a global, high-resolution dataset of translation initiation to track temperature effects on uORF and main ORF initiation rates with utmost precision.This research will provide us with a systems level understanding of how plants tailor translational processes to their temperature environment. It will allow us to better predict how plants will cope with challenging temperatures they are likely to encounter in the future and may ultimately help to create crops that can maintain high yields in a changing climate.