Plant-microbe strategies for utilization of mineral-associated P sources

利用矿物相关磷源的植物微生物策略

• 批准号: 240950800
• 负责人: Professor Dr. Bruno Glaser
• 金额: --
• 依托单位: Professur für Bodenkunde und Bodenschutz
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/240950800?language=en
• 关键词: Plant; microbe; strategies; utilization; mineral

Depleted resources in easy accessible apatite as well as the sorption of inorganic and organic phosphorus (P) to secondary minerals are the main proposed aspects for P limitation of old weathered forest ecosystems. In spite of that indications exist that sorption of P is not irreversible and that life communities are capable to recycle mineral-associated P. But the underlying processes and controlling factors are still poorly known. In this project we will test the hypothesis that particularly in P-limited ecosystems plant-microbe communities can utilize mineral-bound P. We assume that a higher P use efficiency from secondary minerals, especially of sorbed orthophosphate in comparison to P monoesters, is due to an enhanced investment of photosynthates into weathering-active mycorrhiza and bacteria, with such a strategy being realized for both ectomycorrhized plants as well as for plants living in symbiosis with arbuscular fungi. Therefore, mesocosm experiments with soils varying in P supply and amended with additional P sources, i.e. ferrihydrite with adsorbed orthophosphate and P-monoesters, will be run under Fagus sylvatica (ectomycorrhiza) und Acer pseudoplatanus (arbuscular mycorrhiza). 13CO2 isotope labeling and substance-specific 13C analysis in phospholipid fatty acids and low-molecular weight organic acids as well as enzyme activity measurements will inform about the investment of plants into microbial communites as well as weathering agents as a function of soil P availability and P types present. Further, 18O-labeling of phosphate in combination with NanoSIMS application will be used to directly reveal the utilization of mineral-bound P. In a field exposure experiment, P adsorption complexes will be buried and incubated for one year to verify the mesocosms results. Phosphorus losses will be assessed by X-ray fluorescence and photoelectron spectroscopy and the involved microbial communities will be described based on quantitative real-time PCR and 454 pyrosequencing. The obtained data will clarify whether the recycling of P from secondary minerals is a relevant process and which strategies of life are realized.

容易获取的磷灰石资源枯竭以及次生矿物对无机和有机磷（P）的吸附是老风化森林生态系统磷限制的主要方面。尽管有迹象表明磷的吸附并非不可逆，并且生命群落能够回收与矿物相关的磷。但其基本过程和控制因素仍然知之甚少。在本项目中，我们将检验以下假设：特别是在磷有限的生态系统中，植物-微生物群落可以利用矿物结合的磷。我们假设，与磷单酯相比，次生矿物（尤其是吸附的正磷酸盐）的磷利用效率更高。增加光合产物对风化活性菌根和细菌的投入，对于外生菌根植物以及与丛枝真菌共生的植物都实现了这种策略。因此，中生态系统实验将在水青冈（外生菌根）和Acer拟悬铃木（丛枝菌根）下进行，其中土壤的磷供应量不同，并用额外的磷源（即吸附有正磷酸盐和磷单酯的水铁矿）进行修正。磷脂脂肪酸和低分子量有机酸中的 13CO2 同位素标记和物质特异性 13C 分析以及酶活性测量将告知植物对微生物群落以及风化剂的投资，作为土壤 P 可用性和 P 的函数存在的类型。此外，磷酸盐的 18O 标记与 NanoSIMS 应用相结合，将用于直接揭示矿物结合磷的利用。在现场暴露实验中，磷吸附复合物将被掩埋并孵育一年，以验证介观结果。将通过 X 射线荧光和光电子能谱评估磷损失，并将基于定量实时 PCR 和 454 焦磷酸测序描述所涉及的微生物群落。获得的数据将阐明从次生矿物中回收磷是否是一个相关过程以及实现了哪些生命策略。