Texture Dependency of Arbuscular Mycorrhiza-induced Plant Drought Tolerance

水是地球上所有生命的基础，水的可用性应该在人类世的空间和时间中发生变化。具体的知识差距，防止植物根系，土壤微生物和土壤水力特性之间的相互作用的充分机械的理解。因此，该提案收集了三个互补团队的专业知识，量化了土壤干燥后土壤质地和丛枝菌根真菌（AMF）菌丝在土壤-植物（番茄）水分关系中的相互作用。该项目由三个密切相关的工作包（WP）组成。WP 1研究AMF如何影响（i）植物光合作用，（ii）宏观和孔隙尺度土壤水力特性，（iii）植物对水和磷的动员。同步加速器X射线计算机断层扫描和稳定（氘）和放射性（氚，32 P，33 P）同位素标记将在土壤质地和水分梯度。在WP 2中，将利用自动根压室来研究在一系列土壤水分和质地下蒸腾和木质部水势之间的关系。此外，我们采用碳（13 C）和移动的氮（15 NO3-）同位素标记和示踪研究干旱条件下AMF对植物和土壤之间的资源通量的影响。这种资源交换的空间见解将获得耦合中子断层扫描与13 C标记在斑块状分布的土壤质地。WP 3利用前期WPs的实验数据，开发了AMF感染功能-结构植物模型，以量化AMF对根构型和生长的影响。植物水分和养分的吸收将建模和他们的流量量化动态AMF，根系和土壤水力特性之间的反馈。在此基础上，对植物通过根系和AMF吸收资源的碳投资进行了量化。因此，该项目将大大提高我们的理解，如何世界性AMF赋予耐旱性，以其宿主植物在不同的土壤质地。

Availability of water, the basis of all life on Earth, is supposed to change in space and time in the Anthropocene. Specific knowledge gaps prevent full mechanistic understanding of interactions between plant roots, soil microbes, and soil hydraulic properties. Thus, this proposal gathers the expertise of three complementary teams that quantify the interactions between soil texture and arbuscular mycorrhizal fungi (AMF) hyphae in soil-plant (tomato) water relations upon soil drying. The project is composed of three closely interrelated work packages (WP). WP1 investigates how AMF influence (i) plant photosynthesis, (ii) macroscopic and pore-scale soil hydraulic properties, and (iii) mobilization of water and phosphorus by plants. Synchrotron X-ray computer tomography and stable (deuterium) and radioactive (tritium, 32P, 33P) isotope labeling will be employed over gradients of soil textures and moistures. In WP2, an automated root pressure chamber will be utilized to investigate the relationships between transpiration and xylem water potential over a range of soil moistures and textures. Further, we employ carbon (13C) and mobile nitrogen (15NO3-) isotopic labeling and tracing to investigate resource fluxes between plants and soil as affected by AMF under drought. Spatial insights into such resource exchanges will be gained by coupling neutron tomography with 13C labelling in patchily distributed soil textures. WP3 uses the experimental data of the previous WPs for developing AMF infection module for functional-structural plant models to quantify AMF effects on root architecture and growth. Plant water and nutrient uptake will be modelled and their fluxes quantified dynamically by implementing feedbacks between AMF, root systems, and soil hydraulic properties. Based on the previous, carbon investments of plants for resource uptake via roots and via AMF are quantified. This project will thus strongly improve our understanding of how the cosmopolitan AMF confer drought tolerance to their host plants in variable soil textures.