Dirt cheap: an experimental test of controls on resource exchange in an ectomycorrhizal symbiosis
Dirt cheap: an experimental test of controls on resource exchange in an ectomycorrhizal symbiosis
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DOI：
10.1111/nph.18603
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发表时间：
2022-11-29
期刊：
影响因子：
9.4
通讯作者：
Hoeksema，Jason D.
中科院分区：
文献类型：
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作者：
Horning，Amber L.;Koury，Stephanie S.;Hoeksema，Jason D.
为了区分关于资源交换比率在互惠结果中的重要性的假设，我们测量了资源交换比率。通过室内试验，研究了赤松幼苗与两种外生菌根真菌（Rhizopogon roseolus和Pisolithus arhizus）之间的碳（C）、氮（N）和磷（P）转移及其比值，并分析了环境光对这些资源通量和比值的影响（10，20，和30周）和植物和真菌生物量积累的后果，在环境chambers.We的研究结果表明，光的可用性是一个重要的因素驱动的N，P和C的绝对通量，但不是交换率，虽然其影响EM真菌物种之间的变化。下降N：C和P：随着时间的推移，随着土壤养分供应可能下降，碳交换率与生物市场模型的预测是一致的。P的绝对转移是植物和真菌生物量的一个重要预测因子，与过量资源交换假说一致，而N向植物的转移与真菌生物量正相关。总之，光对资源通量的影响表明各种理论框架的混合支持，而生物量增加的结果更好地支持了过量资源交换假说，尽管物种间的变异性需要进一步表征。
To distinguish among hypotheses on the importance of resource‐exchange ratios in outcomes of mutualisms, we measured resource (carbon (C), nitrogen (N), and phosphorus (P)) transfers and their ratios, betweenPinus taedaseedlings and two ectomycorrhizal (EM) fungal species,Rhizopogon roseolusandPisolithus arhizusin a laboratory experiment.We evaluated how ambient light affected those resource fluxes and ratios over three time periods (10, 20, and 30 wk) and the consequences for plant and fungal biomass accrual, in environmental chambers.Our results suggest that light availability is an important factor driving absolute fluxes of N, P, and C, but not exchange ratios, although its effects vary among EM fungal species. Declines in N : C and P : C exchange ratios over time, as soil nutrient availability likely declined, were consistent with predictions of biological market models. Absolute transfer of P was an important predictor of both plant and fungal biomass, consistent with the excess resource‐exchange hypothesis, and N transfer to plants was positively associated with fungal biomass.Altogether, light effects on resource fluxes indicated mixed support for various theoretical frameworks, while results on biomass accrual better supported the excess resource‐exchange hypothesis, although among‐species variability is in need of further characterization.