Biological weathering in soil: the role of symbiotic root-associated fungi biosensing minerals and directing photosynthate-energy into grain-scale mineral weathering
Biological weathering in soil: the role of symbiotic root-associated fungi biosensing minerals and directing photosynthate-energy into grain-scale mineral weathering
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DOI：
10.1180/minmag.2008.072.1.85
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发表时间：
2008-02
影响因子：
2.7
通讯作者：
J. Leake;Adele L. Duran;K. Hardy;Irene Johnson;D. Beerling;Steven A. Banwart;Mark M. Smits
中科院分区：
文献类型：
--
作者：
J. Leake;Adele L. Duran;K. Hardy;Irene Johnson;D. Beerling;Steven A. Banwart;Mark M. Smits
摘要生物风化是生物能量消耗的函数。生物体的生长和新陈代谢产生酸和螯合剂，选择性地吸收营养离子，并施加膨胀压力和其他物理力量，这些力量协同作用，在化学和物理上改变矿物。在非饱和土壤环境中，植物根系通常与真菌形成共生菌根。植物向真菌提供光合作用-碳水化合物-能量，以换取从土壤中吸收并从矿物质中释放的养分。在树木的两种主要菌根之一的外生菌根中，根被真菌覆盖，植物净光合作用的15%-30%通过这些真菌进入土壤，植物吸收的几乎所有水分和养分都通过真菌提供。在这里，我们展示了外生菌根真菌积极地寻找矿物，并作为生物传感器来区分不同的粒度(53-90μm，500-1000μm)和不同的矿物(磷灰石、黑云母、石英)，从而有利于具有高比表面积体积比的颗粒和具有最高磷含量的矿物。真菌的生长和碳分配优先与这些选定的矿物密集相互作用，以最大限度地获取资源。
Abstract Biological weathering is a function of biotic energy expenditure. Growth and metabolism of organisms generates acids and chelators, selectively absorbs nutrient ions, and applies turgor pressure and other physical forces which, in concert, chemically and physically alter minerals. In unsaturated soil environments, plant roots normally form symbiotic mycorrhizal associations with fungi. The plants provide photosynthate-carbohydrate-energy to the fungi in return for nutrients absorbed from the soil and released from minerals. In ectomycorrhiza, one of the two major types of mycorrhiza of trees, roots are sheathed in fungus, and 15-30% of the net photosynthate of the plants passes through these fungi into the soil and virtually all of the water and nutrients taken up by the plants are supplied through the fungi. Here we show that ectomycorrhizal fungi actively forage for minerals and act as biosensors that discriminate between different grain sizes (53-90 μm, 500-1000 μm) and different minerals (apatite, biotite, quartz) to favour grains with a high surface-area to volume ratio and minerals with the highest P content. Growth and carbon allocation of the fungi is preferentially directed to intensively interact with these selected minerals to maximize resource foraging.