How does temperature influence AMF respiration?

丛枝菌根真菌(AMF)是分布最广、生态意义最大的土壤微生物之一。这些土壤真菌与约三分之二的陆地植物(约20万种)形成共生关系，双方都从中受益。当真菌从寄主植物获得碳供应时，植物获得了增强的磷吸收和其他好处，例如提高了对病原菌的抵抗力。此外，丛枝菌根真菌(AMF)还可以影响自然生态系统中的植物群落结构和养分循环，并向周围土壤释放大量的呼吸性二氧化碳，最终扩散到大气中(导致温室效应)。因此，令人惊讶的是，我们对这类有影响力的真菌如何对环境条件做出反应知之甚少。温度是这种关键环境变量之一，因为它影响新陈代谢过程，可以表现出很大的变化(即昼夜、冬季和夏季)，并且预计会随着全球气候变化而增加。虽然我们知道植物对温度变化的反应，但大多数关于AMF的研究都是使用非菌根(即未定植)植物进行的，而在自然环境中，AMF定植是正常情况。在这个方案中，我们将通过测量呼吸来研究AMF是如何受到温度的影响的。我们将研究AMF如何影响植物根的呼吸反应(与未定居的根相比)。此外，AMF有两个阶段，一个在根内，另一个在根外，负责探索土壤中的养分。目前尚不清楚这两个相是否以相同的方式对温度做出反应。我们将改变外部相经历的温度，而不是工厂的温度，这样就可以直接检测AMF的响应。我们还将测试真菌是否能够适应温度的变化，从而使呼吸保持稳定状态，而不是变化。

Arbuscular mycorrhizal fungi (AMF) are among the most widespread and ecologically significant of all soil micro-organisms. These soil fungi form symbiotic associations with around two-thirds of all land plants (some 200 000 species) in which both partners benefit. The plant obtains enhanced phosphorus uptake and other benefits such as increased pathogen resistance while the fungus receives a supply of carbon from its host plant. In addition, arbuscular mycorrhizal fungi (AMF) are known to influence plant community structure and nutrient cycling in natural ecosystems as well as releasing large amounts of respiratory CO2 into the surrounding soil, which ultimately diffuses into the atmosphere (contributing to the greenhouse effect). It is therefore surprising that we know relatively little about how this influential group of fungi respond to conditions in the environment. Temperature is one such key environmental variable because it effects metabolic processes, can show wide variation (i.e. day and night, winter and summer) and is predicted to increase as a result of global climate change. Although we do know how plants respond to variations in temperature, most studies on have been conducted using non-mycorrhizal (i.e. uncolonised) plants whereas in the natural environment AMF colonisation is the normal condition. In this proposal we will investigate how the AMF is influenced by temperature by measuring respiration. We will examine how AMF influence the respiration response of the plants root (compared to uncolonised roots). In addition, the AMF has two phases, one inside the root, and the other external to the root responsible for exploring the soil for nutrients. If both these phases respond to temperature in the same manner is currently unknown. We will vary the temperature experienced by the external phase independently of that of the plant so that the response of the AMF can be examined directly. We will also test if the fungus is able to adjust (i.e. acclimate) to changes in temperature such that respiration is maintained in a steady state rather than changing.