Collaborative Research: Elucidating the chemical plasticity of fine roots in response to soil heterogeneities and developing a better parameter to forecast fine root decomposition

植物通过改变根的生长模式和化学成分来适应土壤环境，这会影响植物吸收养分和水分的方式。对根对胁迫的反应缺乏了解，这是了解植物对环境变化的反应的障碍。此外，根分解的速度会影响从死根组织中回收营养的方式，这可能会进一步影响植物的生长。然而，目前的根分解模型是基于已知的植物地上部分的分解，如叶和茎。此外，人们对根系化学成分随当地土壤条件的变化知之甚少，这限制了人们对植物对营养贫瘠的土壤的反应，或这反过来如何影响土壤养分循环的了解。这项研究将研究土壤条件和微生物如何影响北美东部重要森林树种的根化学。这项研究的结果还将通过纳入根的化学成分来改进根的分解模型。这个项目还将为社会带来几个好处。它将为高中生创建讲习班，并为K-12教师开设暑期课程和课程开发材料。它还将为本科生、研究生和博士后研究人员提供培训。细根(直径小于2毫米)对植物适应和关键生态系统过程的影响不成比例地大，但它们仍然是陆地生物圈模型中最不被理解的组成部分之一。预测地上组织分解的常用参数，如元素比率，不能充分预测细根的分解。这一建议的中心假设是，这种脱节是由于根的独特化学结构，这是由其直接的生物和非生物土壤环境塑造的。PIS建议调查不同树种在不同土壤资源可用性下发育的细根的化学可塑性，以及与不同种类的菌根真菌的联系。PI将通过分解实验和利用先进的成像和光谱技术，将观察到的化学可塑性与细根的分解动力学联系起来。PIs建议开发包含根化学的参数，以改进对细根分解的预测。拟议的项目将是第一次尝试全面了解促进植物胁迫适应的细根分子水平的化学图谱，并开发稳健的参数来预测细根分解和土壤有机质的形成。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Plants adapt to their soil environment through changes in patterns of root growth and chemical composition, which influence how plants take up nutrients and water. Poor understanding of how roots respond to stress is an obstacle to understanding plant responses to environmental change. In addition, how quickly roots decompose affects how nutrients are recycled from dead root tissues, which can further influence plant growth. However, current models of root decomposition are based on what is known about the breakdown of aboveground parts of plants, like leaves and stems. Furthermore, little is known about how root chemistry varies with local soil conditions which limits understanding of how plants respond to nutrient poor soils, or how this in turn influences soil nutrient recycling. This research will study how soil conditions and microbes influence root chemistry of important forest tree species in eastern North America. Results of this research will also improve models of root decomposition by incorporating root chemical composition. This project will also provide several benefits to society. It will create workshops for high school students and a summer course and curriculum development materials for K-12 teachers. It will also provide training for undergraduates, graduate students and a postdoctoral researcher.Fine roots (less than 2mm diameter) have a disproportionately large influence on plant adaptation and key ecosystem processes, yet they remain one of the least understood components of Terrestrial Biosphere Models. Commonly used parameters, such as element ratios, that predict decomposition of aboveground tissues fail to adequately predict the decomposition of fine roots. The central hypothesis of this proposal is that this disconnect is due to the unique chemical construction of roots, which is shaped by their immediate biotic and abiotic soil environments. The PIs propose to investigate the chemical plasticity in fine roots of different tree species developed under different soil resource availabilities and associations with different species of mycorrhizal fungi. The PIs will link observed chemical plasticity to decomposition dynamics of fine roots using decomposition experiments and by utilizing advanced imaging and spectroscopy techniques. The PIs propose to develop parameters that incorporate root chemistry to improve predictions of fine-root decomposition. The proposed project would be one of the first attempts to obtain a comprehensive understanding of the molecular-level chemical profile of fine-roots that facilitate plant stress adaptation, and to develop robust parameters to predict fine-root decomposition and soil organic matter formation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.