黄土区深层土壤微生物对刺槐根系水分吸收的影响机制

在黄土高原半干旱区，土壤水文过程是维持生态系统健康的重要过程。特别是在全球变化背景下，植被根系的水分吸收效率已经成为黄土高原区植被恢复的关键因子之一。刺槐林是黄土高原植被恢复的主要人工林类型，其对深层土壤水分的吸收利用策略对维持黄土高原地区生态恢复具有重要意义和典型性。土壤微生物参与了生态系统中绝大多数的功能过程，然而土壤微生物对植物根系吸收深层土壤水分过程的影响机制尚不清楚。本项目拟基于野外大型降水控制试验平台，采用高通量测序和真核转录组测序等分子生物学技术，结合中子仪原位观测、稳定同位素等土壤水文学方法，分析深层（1-5 m）土壤微生物群落特征和功能、土壤理化性质、刺槐根系生理与根系水分吸收相关功能基因表达之间的定量关系，探究深层土壤微生物对根系水分吸收相关功能基因的表达的影响，进而阐明深层土壤微生物对根系水分吸收的影响机制，以期为黄土高原地区人工林生态规划和可持续发展提供理论支撑。

Soil hydrological process is a crucial process to maintain ecosystem health in the semi-arid area of Loess Plateau. Under the background of global change, the water uptake efficiency of plant roots has become one of the key factors of vegetation restoration in the Loess Plateau. Robinia pseudoacacia is the main type of planted forest for vegetation restoration in the Loess Plateau, its strategies of absorption and utilization of deep soil water are typical and of great significance for ecological restoration in the Loess Plateau. Soil microorganisms drive innumerable functional processes in ecosystems. However, the mechanism of the effect of soil microorganisms on the process of deep soil water uptake by plant roots is still unclear. Base on the large-scale platform of precipitation manipulation experiment, this project will use molecular biology technologies such as high-throughput sequencing and eukaryotic transcriptome sequencing, combined with soil hydrology methods such as in-situ observation with neutron probe and stable isotope method to analyze the quantitative relationship between the microbial community structure and functions, soil physical and chemical properties, as well as the root physiology and the expression of functional genes related to root water absorption in deep soil. And further explore the influence of soil microorganisms on the expression of functional genes related to root water absorption to clarify the influencing mechanism of deep soil microorganisms on the process of root water absorption. This project will provide theoretical support for the ecological planning and sustainable development of planted forests in the Loess Plateau.