Data from: Linking the respiration of fungal sporocarps with their nitrogen concentration: variation among species, tissues, and guilds

Tissue nitrogen (N) concentration has been correlated with respiration (RS) across plants of different life forms, functional and phylogenetic groups, plant organs and ectomycorrhizae of different fungal species. Nothing is known, however, if a similar relationship exists in other organisms like fungi. Here, we explored the N-RS relationship across sporocarps of 93 fungal species that varied in their guilds (mutualistic, saprotrophic, and parasitic) as well as “tissue” types (caps and stipes). We hypothesized that RS, N and protein concentrations were higher for saprotrophic fungi than either mutualistic and parasitic fungi and were higher for caps than for stipes. We also hypothesized that respiration of fungal guild could be predicted by the N concentration. Lastly we predicted N and RS were phylogenetically conserved and that by subtracting metabolically inactive N in chitin, we could improve the N-RS relationship. Sporocarp N concentration only explained 26% of the variation in RS across species. We found a significant difference in the N-RS relationship among the three fungal guilds, but no difference between the two tissue types. Saprotrophic species had higher N concentration and respiration than mutualistic and parasitic fungal species. Sporocarp components differed with caps showing both higher respiration and higher N and protein concentrations than stipes. Overall, our results show that fungal sporocarp nitrogen concentration is phylogenetically conserved among fungal families and may prove to be a strong predictor of fungal guild. The positive N-RS relationships existed for all fungal species (similar to plants), within fungal guilds (similar to plant functional groups), and fungal “tissue” types (like plants’ organs). The clear linkage of fungal sporocarp respiration to total N concentration could help improve C and N cycling models in forest ecosystems by including estimates of fungal respiration based on fungal N concentration.

组织氮（N）浓度与呼吸速率（RS）已被证实存在相关性，相关研究涵盖不同生活型、功能类群与系统发育类群的植物，以及不同真菌物种的植物器官和外生菌根（ectomycorrhizae）。然而，目前尚不清楚类似的相关性是否存在于真菌等其他生物类群中。本研究针对93个不同功能群（互利共生型、腐生型、寄生型）及不同“组织”类型（菌盖与菌柄）的真菌物种子实体（sporocarps），探究了其N-RS相关性。我们提出如下假说：腐生型真菌的呼吸速率、氮浓度与蛋白质浓度均高于互利共生型与寄生型真菌，且菌盖的上述指标均高于菌柄。此外，我们还提出假说：不同真菌功能群的呼吸速率可通过氮浓度进行预测。最后，我们预测氮浓度与呼吸速率具有系统发育保守性；且通过扣除几丁质（chitin）中的代谢非活性氮，可优化N-RS相关性模型。子实体氮浓度仅能解释不同物种间呼吸速率变异的26%。研究发现，三种真菌功能群间的N-RS相关性存在显著差异，但两种组织类型间无显著差异。腐生型真菌物种的氮浓度与呼吸速率均高于互利共生型与寄生型真菌。子实体不同组分间存在差异：菌盖的呼吸速率、氮浓度与蛋白质浓度均高于菌柄。总体而言，本研究结果表明，真菌子实体的氮浓度在真菌科水平上具有系统发育保守性，且可作为真菌功能群的有效预测因子。所有真菌物种（与植物研究结果一致）、真菌功能群内（与植物功能群研究结果一致）以及真菌“组织”类型（与植物器官研究结果一致）中，均存在N-RS正相关关系。真菌子实体呼吸速率与总氮浓度间的明确关联，可通过纳入基于真菌氮浓度的真菌呼吸速率估算参数，助力森林生态系统碳氮循环模型的优化完善。