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.

易获得的磷灰石资源枯竭以及次生矿物对无机磷和有机磷的吸附是古老风化森林生态系统磷限制的主要方面。尽管存在的迹象表明，吸附的P是不可逆的，生命群落能够回收矿物相关的P，但基本的过程和控制因素仍然知之甚少。在这个项目中，我们将测试的假设，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磷。我们假设，较高的磷利用效率从次生矿物，特别是吸附的正磷酸盐相比，磷单酯，是由于增加投资的光合作用到风化活性的菌根和细菌，对于外生菌根化的植物以及与丛枝真菌共生的植物都实现了这种策略。因此，与土壤不同的磷供应和补充额外的磷源，即吸附的正磷酸盐和P-单酯的水铁矿，将在水青冈（外生菌根）和槭pseudoplatanus（丛枝菌根）下运行中围实验。13 CO2同位素标记和磷脂脂肪酸和低分子量有机酸中的物质特异性13 C分析以及酶活性测量将告知植物对微生物群落的投资以及风化剂作为土壤P可用性和P类型的函数。此外，18 O-标记的磷酸盐结合NanoSIMS应用程序将被用来直接揭示利用矿物结合P.在现场暴露实验中，P吸附复合物将被掩埋并孵育一年，以验证围隔生态系统的结果。磷损失将通过X射线荧光和光电子能谱进行评估，并将根据定量实时PCR和454焦磷酸测序来描述所涉及的微生物群落。所获得的数据将阐明是否从次生矿物中回收磷是一个相关的过程，以及实现了哪些生活策略。