Plant family identity distinguishes patterns of carbon and nitrogen stable isotope abundance and nitrogen concentration in mycoheterotrophic plants associated with ectomycorrhizal fungi
Plant family identity distinguishes patterns of carbon and nitrogen stable isotope abundance and nitrogen concentration in mycoheterotrophic plants associated with ectomycorrhizal fungi
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DOI：
10.1093/aob/mcw119
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发表时间：
2016-09-01
期刊：
影响因子：
4.2
通讯作者：
Gebauer, Gerhard
中科院分区：
文献类型：
--
作者：
Hynson, Nicole A.;Schiebold, Julienne M. -I.;Gebauer, Gerhard
背景和目的真菌异养是指植物通过与根栖菌根真菌的共生相互作用来满足全部或部分碳(C)需求。真菌异养生物的生态生理特征，如它们的碳稳定同位素丰度，与物种对真菌碳获取的依赖程度（相对于通过光合作用获得的碳）密切相关。植物进化史与真菌异养植物生态生理之间的关系研究较少。我们假设完全和部分真菌异养物种的C和N稳定同位素组成以及N浓度与自养物种区分，植物家族身份可能是物种之间这些性状差异的另一个重要解释因素。我们集中研究了与外生菌根真菌有关的异养真菌，这些真菌来自Ericaceae和兰科植物家族。方法收集各植物科全部（N = 18）和部分（N = 22）真菌异养物种及相应自养参考物种（N = 156）已发表和未发表的N浓度、C和N稳定同位素丰度（δ C-13和δ N-15）数据。这些数据被用于计算与位点无关的C和N稳定同位素富集因子（epsilon）。然后，我们测试了不同植物科和营养策略之间N浓度、C-13和N-15富集的差异。本研究发现，C和N稳定同位素富集除了可以区分部分和完全真菌异养物种和自养物种外，还可以根据家族身份区分植物物种。氮浓度的差异集中在植物科水平，而不是对真菌异养的依赖程度。结论稳定同位素组成和氮浓度的差异与植物与真菌及其环境的生理相互作用有关。
Background and Aims Mycoheterotrophy entails plants meeting all or a portion of their carbon (C) demands via symbiotic interactions with root-inhabiting mycorrhizal fungi. Ecophysiological traits of mycoheterotrophs, such as their C stable isotope abundances, strongly correlate with the degree of species' dependency on fungal C gains relative to C gains via photosynthesis. Less explored is the relationship between plant evolutionary history and mycoheterotrophic plant ecophysiology. We hypothesized that the C and nitrogen (N) stable isotope compositions, and N concentrations of fully and partially mycoheterotrophic species differentiate them from autotrophs, and that plant family identity would be an additional and significant explanatory factor for differences in these traits among species. We focused on mycoheterotrophic species that associate with ectomycorrhizal fungi from plant families Ericaceae and Orchidaceae.Methods Published and unpublished data were compiled on the N concentrations, C and N stable isotope abundances (delta C-13 and delta N-15) of fully (n = 18) and partially (n = 22) mycoheterotrophic species from each plant family as well as corresponding autotrophic reference species (n = 156). These data were used to calculate site-independent C and N stable isotope enrichment factors (epsilon). Then we tested for differences in N concentration, C-13 and N-15 enrichment among plant families and trophic strategies.Key Results We found that in addition to differentiating partially and fully mycoheterotrophic species from each other and from autotrophs, C and N stable isotope enrichment also differentiates plant species based on familial identity. Differences in N concentrations clustered at the plant family level rather than the degree of dependency on mycoheterotrophy.Conclusions We posit that differences in stable isotope composition and N concentrations are related to plant family-specific physiological interactions with fungi and their environments.