Tlalka M, Bebber D P, Darrah P R, Watkinson S C, Fricker M D
Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
Fungal Genet Biol. 2007 Nov;44(11):1085-95. doi: 10.1016/j.fgb.2007.02.013. Epub 2007 Mar 13.
Fungi play a central role in the nutrient cycles of boreal and temperate forests. In these biomes, the saprotrophic wood-decay fungi are the only organisms that can completely decompose woody plant litter. In particular, cord-forming basidiomycete fungi form extensive mycelial networks that scavenge scarce mineral nutrients and translocate them over long distances to exploit new food resources. Despite the importance of resource allocation, there is limited information on nutrient dynamics in these networks, particularly for nitrogen, as there is no suitable radioisotope available. We have mapped N-translocation using photon-counting scintillation imaging of the non-metabolised amino acid analogue, (14)C-aminoisobutyrate. We describe a number of novel phenomena, including rapid, preferential N-resource allocation to C-rich sinks, induction of simultaneous bi-directional N-transport, abrupt switching between different pre-existing transport routes, and emergence of locally synchronised, oscillatory phase domains. It is possible that such self-organised oscillatory behaviour is a mechanism to achieve global co-ordination in the mycelium.
真菌在北方和温带森林的养分循环中起着核心作用。在这些生物群落中，腐生木材腐朽真菌是唯一能够完全分解木本植物凋落物的生物体。特别是，形成菌索的担子菌真菌形成广泛的菌丝网络， scavenge 稀缺的矿物质养分，并将它们长距离转运以开发新的食物资源。尽管资源分配很重要，但关于这些网络中养分动态的信息有限，尤其是对于氮，因为没有合适的放射性同位素可用。我们使用非代谢氨基酸类似物（14）C-氨基异丁酸的光子计数闪烁成像绘制了氮转运图。我们描述了许多新现象，包括快速、优先将氮资源分配到富含碳的汇中，诱导同时双向氮运输，在不同的预先存在的运输路线之间突然切换，以及出现局部同步的振荡相域。这种自组织振荡行为有可能是一种在菌丝体中实现全局协调的机制。
