Centre for Crop System Analysis, Wageningen University, PO Box 430, Wageningen, 6700 AK, the Netherlands.
Institute for Integrative Biology, ETH Zürich, Zürich, 8092, Switzerland.
New Phytol. 2021 Aug;231(3):1171-1182. doi: 10.1111/nph.17435. Epub 2021 May 30.
Recent studies show that the variation in root functional traits can be explained by a two-dimensional trait framework, containing a 'collaboration' axis in addition to the classical fast-slow 'conservation' axis. This collaboration axis spans from thin and highly branched roots that employ a 'do-it-yourself' strategy to thick and sparsely branched roots that 'outsource' nutrient uptake to symbiotic arbuscular mycorrhizal fungi (AMF). Here, we explore the functionality of this collaboration axis by quantifying how interactions with AMF change the impact of root traits on plant performance. To this end, we developed a novel functional-structural plant (FSP) modelling approach that simulates plants competing for light and nutrients in the presence or absence of AMF. Our simulation results support the notion that in the absence of AMF, plants rely on thin, highly branched roots for their nutrient uptake. The presence of AMF, however, promotes thick, unbranched roots as an alternative strategy for uptake of immobile phosphorus, but not for mobile nitrogen. This provides further support for a root trait framework that accommodates for the interactive effect of roots and AMF. Our modelling study offers unique opportunities to incorporate soil microbial interactions into root functionality as it integrates consequences of belowground trait expression.
最近的研究表明，根功能性状的变化可以用一个二维性状框架来解释，该框架除了经典的快速-慢速“保守”轴之外，还包含一个“协作”轴。这个协作轴从细而高度分支的根跨越到厚而稀疏分支的根，后者将养分吸收“外包”给共生的丛枝菌根真菌（AMF）。在这里，我们通过量化根性状与 AMF 的相互作用如何改变植物性能来探索这个协作轴的功能。为此，我们开发了一种新的功能结构植物（FSP）建模方法，该方法模拟了在有或没有 AMF 的情况下，植物为争夺光和养分而竞争的情况。我们的模拟结果支持了这样一种观点，即在没有 AMF 的情况下，植物依靠细而高度分支的根来吸收养分。然而，AMF 的存在促进了厚而不分枝的根作为吸收不移动磷的替代策略，但不能作为吸收移动氮的替代策略。这为根性状框架提供了进一步的支持，该框架考虑了根和 AMF 的相互作用的影响。我们的建模研究提供了独特的机会，可以将土壤微生物相互作用纳入根功能中，因为它整合了地下性状表达的后果。
