Bavarian Forest National Park, Freyunger Str. 2, 94481, Grafenau, Germany.
Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Adeilad Cledwyn, Penglais, Aberystwyth, Ceredigion, SY23 3DD, Wales, UK.
Environ Microbiol. 2018 Oct;20(10):3573-3588. doi: 10.1111/1462-2920.14327.
Several lines of evidence suggest that the agaricoid, non-ectomycorrhizal members of the family Hygrophoraceae (waxcaps) are biotrophic with unusual nitrogen nutrition. However, methods for the axenic culture and lab-based study of these organisms remain to be developed, so our current knowledge is limited to field-based investigations. Addition of nitrogen, lime or organophosphate pesticide at an experimental field site (Sourhope) suppressed fruiting of waxcap basidiocarps. Furthermore, stable isotope natural abundance in basidiocarps were unusually high in N and low in C, the latter consistent with mycorrhizal nutritional status. Similar patterns were found in waxcap basidiocarps from diverse habitats across four continents. Additional data from C analysis of basidiocarps and C pulse label experiments suggest that these fungi are not saprotrophs but rather biotrophic endophytes and possibly mycorrhizal. The consistently high but variable δ N values (10-20‰) of basidiocarps further indicate that N acquisition or processing differ from other fungi; we suggest that N may be derived from acquisition of N via soil fauna high in the food chain.
有几条证据表明，属于 Hygrophoraceae 科（蜡伞科）的非外生菌根、担子菌类是具有特殊氮营养的生物营养体。然而，这些生物体的无菌培养和实验室研究方法仍有待开发，因此我们目前的知识仅限于基于野外的调查。在实验场地（Sourhope）添加氮、石灰或有机磷农药会抑制蜡伞菌担子果的结实。此外，担子果中的稳定同位素自然丰度在 N 中异常高，在 C 中异常低，后者与菌根的营养状况一致。在来自四大洲不同生境的蜡伞菌担子果中也发现了类似的模式。来自担子果 13 C 分析和 13 C 脉冲标记实验的其他数据表明，这些真菌不是腐生菌，而是生物营养内生菌，可能是菌根菌。担子果始终较高但变化较大的 δ N 值（10-20‰）进一步表明，氮的获取或处理与其他真菌不同；我们推测 N 可能来自食物链中较高的土壤动物通过获取 N。
