Steinauer Katja, Thakur Madhav P, Emilia Hannula S, Weinhold Alexander, Uthe Henriette, van Dam Nicole M, Martijn Bezemer T
Department of Terrestrial Ecology, The Netherlands Institute of Ecology, Wageningen, The Netherlands.
Institute of Plant Science, University of Bern, Bern, Switzerland.
Plant Cell Environ. 2023 Jun;46(6):1885-1899. doi: 10.1111/pce.14570. Epub 2023 Feb 27.
Plants influence numerous soil biotic factors that can alter the performance of later growing plants-defined as plant-soil feedback (PSF). Here, we investigate whether PSF effects are linked with the temporal changes in root exudate diversity and the rhizosphere microbiome of two common grassland species (Holcus lanatus and Jacobaea vulgaris). Both plant species were grown separately establishing conspecific and heterospecific soils. In the feedback phase, we determined plant biomass, measured root exudate composition, and characterised rhizosphere microbial communities weekly (eight time points). Over time, we found a strong negative conspecific PSF on J. vulgaris in its early growth phase which changed into a neutral PSF, whereas H. lanatus exhibited a more persistent negative PSF. Root exudate diversity increased considerably over time for both plant species. Rhizosphere microbial communities were distinct in conspecific and heterospecific soils and showed strong temporal patterns. Bacterial communities converged over time. Using path models, PSF effects could be linked to the temporal dynamics of root exudate diversity, whereby shifts in rhizosphere microbial diversity contributed to temporal variation in PSF to a lesser extent. Our results highlight the importance of root exudates and rhizosphere microbial communities in driving temporal changes in the strength of PSF effects.
植物会影响众多土壤生物因子，这些因子能够改变后期生长植物的表现，即植物-土壤反馈（PSF）。在此，我们研究植物-土壤反馈效应是否与两种常见草地物种（绒毛草和普通千里光）根系分泌物多样性和根际微生物组的时间变化有关。这两种植物分别种植，形成同种和异种土壤。在反馈阶段，我们每周（共八个时间点）测定植物生物量、测量根系分泌物组成并对根际微生物群落进行特征分析。随着时间推移，我们发现普通千里光在其生长早期阶段存在强烈的同种负植物-土壤反馈，这种反馈后来转变为中性反馈，而绒毛草则表现出更为持久的负植物-土壤反馈。两种植物的根系分泌物多样性均随时间显著增加。同种和异种土壤中的根际微生物群落各不相同，并呈现出强烈的时间模式。细菌群落随时间逐渐趋同。通过路径模型，植物-土壤反馈效应可与根系分泌物多样性的时间动态联系起来，其中根际微生物多样性的变化对植物-土壤反馈时间变化的贡献较小。我们的研究结果突出了根系分泌物和根际微生物群落在驱动植物-土壤反馈效应强度的时间变化方面的重要性。
