Plants acclimate their photosynthetic capacity in response to changing environmental conditions. In Arabidopsis thaliana, photosynthetic acclimation to cold requires the accumulation of the organic acid fumarate, catalysed by a cytosolic fumarase FUM2, however the role of this is currently unclear. In this study, we use an integrated experimental and modelling approach to examine the role of FUM2 and fumarate across the physiological temperature range. Using physiological and biochemical analyses, we demonstrate that FUM2 is necessary for high as well as low temperature acclimation. To understand the role of FUM2 activity, we have adapted a reliability engineering technique, Failure Mode and Effect Analysis (FMEA), to formalize a rigorous approach for ranking metabolites according to the potential risk that they pose to the metabolic system. FMEA identifies fumarate as a low-risk metabolite. Its precursor, malate, is shown to be high-risk and liable to cause system instability. We conclude that the role of cytosolic fumarase, FUM2, is to provide a fail-safe, maintaining system stability under changing environmental conditions. We argue that FMEA is a technique which is not only useful in understanding plant metabolism, it can also be used to study reliability in other systems and aid the design of synthetic pathways.

中文翻译：

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植物代谢的失效模式和效应分析揭示了为什么拟南芥温度适应需要胞质富马酸酯酶

植物可以响应不断变化的环境条件来适应其光合能力。在拟南芥中，光合作用适应寒冷需要通过胞质富马酸酶FUM2催化富马酸有机酸的积累，但是目前尚不清楚其作用。在这项研究中，我们使用集成的实验和建模方法来检查FUM2和富马酸酯在整个生理温度范围内的作用。使用生理和生化分析，我们证明FUM2是高温和低温驯化所必需的。为了了解FUM2活性的作用，我们采用了可靠性工程技术，即失效模式和效应分析（FMEA），以根据其对代谢系统造成的潜在风险，对严格的方法进行分级，以对代谢物进行分级。FMEA将富马酸酯鉴定为低风险代谢产物。它的前体苹果酸被证明是高风险的，容易引起系统不稳定。我们得出的结论是，胞质富马酸酯FUM2的作用是提供故障保护功能，在不断变化的环境条件下保持系统稳定性。我们认为FMEA是一种不仅可用于了解植物代谢的技术，而且还可用于研究其他系统的可靠性并帮助设计合成途径。