Data_Sheet_1_Interactive effects between the invasive weed Stellera chamaejasme and grass: can arbuscular mycorrhizal fungi and fungal pathogens coregulate interspecific relationships?.pdf

The interaction between poisonous weeds and neighboring plants is complex. Poisonous weeds frequently have a competitive advantage in the interaction between poisonous weeds and neighboring plants. Arbuscular mycorrhizal fungi (AMF) and plant pathogenic fungi (PPF) are closely related to the interspecific relationships of plants. However, the role of AMF and PPF between poisonous weeds and neighboring grasses remains unclear. Here, we designed a pot experiment to determine the interspecific relationship between Leymus chinensis and Stellera chamaejasme and the regulation of AMF and PPF. The results showed that interactive effects between L. chinensis and S. chamaejasme significantly inhibited the aboveground growth of both but promoted the underground growth of L. chinensis. As the proportions of S. chamaejasme increased, the total nitrogen content and pH in the rhizosphere soil of L. chinensis were reduced, the soil pH of S. chamaejasme was reduced, and the relative abundance of AMF in the rhizosphere soil of L. chinensis significantly increased and that of S. chamaejasme decreased considerably. The relative abundances of PPF in the rhizosphere soil of both in the mono-cultures were significantly higher than those in the mixed cultures. Structural equation modeling indicated that soil abiotic (pH and N availability) and biotic (AMF and PPF) factors are major drivers explaining the interactive effects between L. chinensis and S. chamaejasme. We provided new evidence for the interspecific interactions between poisonous weeds and neighboring grasses and revealed the regulatory role of AMF and PPF in the interactive effects of both plants. This study will provide a scientific basis for the prevention and control of poisonous weeds and the vegetation restoration of degraded grasslands in the future.

有毒杂草与周边植物的种间互作机制复杂，且有毒杂草往往在该互作中占据竞争优势。丛枝菌根真菌（Arbuscular mycorrhizal fungi, AMF）与植物病原真菌（plant pathogenic fungi, PPF）均与植物的种间关系密切相关，但二者在有毒杂草与周边禾草的互作过程中所发挥的调控作用仍不明晰。本研究设置盆栽试验，旨在探究羊草（Leymus chinensis）与狼毒（Stellera chamaejasme）的种间关系，以及丛枝菌根真菌与植物病原真菌的调控效应。结果表明，羊草与狼毒的种间互作显著抑制了二者的地上部生长，却促进了羊草的地下部生长。随着狼毒种植占比提升，羊草根际土壤的全氮含量与pH值均显著降低；狼毒根际土壤pH值亦有所下降；羊草根际土壤中丛枝菌根真菌的相对丰度显著升高，而狼毒根际的该真菌相对丰度则大幅降低。单作模式下，两种植物根际的植物病原真菌相对丰度均显著高于混作模式。结构方程模型分析显示，土壤非生物因子（pH与氮素有效性）及生物因子（丛枝菌根真菌与植物病原真菌）是解释羊草与狼毒种间互作效应的核心驱动因素。本研究为有毒杂草与周边禾草的种间互作提供了新的实证证据，并揭示了丛枝菌根真菌与植物病原真菌在两种植物互作过程中的调控作用。本研究可为未来有毒杂草的防控及退化草地植被修复提供科学理论依据。