C allocation to the fungus is not a cost to the plant in ectomycorrhizae
C allocation to the fungus is not a cost to the plant in ectomycorrhizae
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DOI：
10.1111/j.1600-0706.2011.19406.x
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发表时间：
2012-03-01
期刊：
影响因子：
3.4
通讯作者：
Cruz, C.
中科院分区：
文献类型：
--
作者：
Correa, A.;Gurevitch, J.;Cruz, C.
菌根对植物的益处通常是通过菌根(M)和非菌根（NM）植物的生长差异来评估的。这些生长差异通常被认为是由于地下碳消耗的差异，或成本效率的差异，即每消耗碳所获得的养分量。我们检索了外生菌根（ECM）与非菌根（ECM）植物生长与地下碳分配、碳利用效率或养分吸收之间关系的已发表报告。我们发现了类似数量的ECM对植物生长的负面、无效或正面影响。这些效应与普通植物和普通植物在地下碳分配和碳利用效率上的差异不相关。相反，它们与菌根对植物氮增益的影响呈极强相关。因此，对已发表数据的综合分析提供了证据，证明C是一种过剩资源，而不是一种昂贵的资源，并且共生的结果仅取决于菌根与NM植物相比是否增加或减少了养分获取，而不取决于M和NM植物之间的成本效率差异。讨论了这一发现对共生体之间资源交换调节和共生性质的影响。
Mycorrhizal benefit to plants is most frequently evaluated through growth differences between mycorrhizal (M) and non-mycorrhizal (NM) plants. These growth differences are often considered to be due to differences in belowground C expenditure, or in cost efficiency, i.e. amount of nutrients acquired per C expended.We searched published reports for relations between plant growth and belowground C allocation, C use efficiency, or nutrient uptake, in ectomycorrhizal (ECM) versus non-mycorrhizal plants. We found a similar number of cases of negative, null or positive effects of ECM on plant growth. These effects were not correlated with differences on belowground C allocation or C use efficiency between M and NM plants. In contrast, they were very strongly correlated with mycorrhizal effects on plant N gain.A comprehensive analysis of the published data therefore provided evidence that C is an excess, rather than a costly, resource, and that the outcome of the symbiosis depends only on whether mycorrhizae result in increased or decreased nutrient acquisition compared with NM plants, and not on cost efficiency differences between M and NM plants. Consequences of this finding for the regulation of resource exchange between symbionts and the nature of the symbiosis are discussed.