DISSERTATION RESEARCH: Testing the role of arbuscular mycorrhizal fungi in plant adaptation to serpentine soil

植物对土壤物理和化学环境的适应，或土壤因素，已知会影响植物的分布、多样性和物种形成。然而，植物对土壤因子的适应机制尚不完全清楚。传统上，土壤适应性的研究主要集中在土壤条件对植物生长和繁殖的直接影响上。将探索一种新的理论和实验框架，其中植物对土壤因子的适应是通过丛枝菌根(AM)真菌来调节的。本研究的目标是确定适应的植物生态型是否需要特定的AM真菌分类群，蛇纹岩土壤是否形成AM真菌组合，以及AM真菌是否影响蛇纹岩土壤中植物的生长和适合性。到目前为止的发现表明，植物生态型与田间不同的AM真菌组合有关。这个项目使用蛇纹石，一种天然有毒的土壤，来测试常见的根共生体，丛枝菌根真菌，在植物适应极端压力的土壤环境中的作用。更广泛的影响包括对分类学和教育的贡献，以及在保护和生物修复方面的潜在应用。以前未知的真菌物种很可能与蛇纹石土壤上的植物有关。本科生和博士生将接受微生物生物学一个重要领域的培训。收集和鉴定真菌是脆弱的植物学重要生态系统的关键组成部分，可以极大地提高当地濒危或稀有物种恢复工作的成功率。真菌具有独特的生理功能，可用于有毒部位的生物修复。

Plant adaptation to soil physical and chemical environments, or edaphic factors, is known to influence plant distribution, diversification, and speciation. However, the mechanisms of plant adaptation to edaphic factors are not fully understood. Traditionally, the study of edaphic adaptation has focused on the direct effects of soil conditions on plant growth and reproduction. A new theoretical and experimental framework will be explored, in which plant adaptation to edaphic factors is mediated through arbuscular mycorrhizal (AM) fungi. The goals of this research are to determine if adapted plant ecotypes require specific AM fungal taxa, if serpentine soils shape AM fungal assemblages, and if AM fungi impact plant growth and fitness in serpentine soil. Findings thus far show that the plant ecotypes associate with distinct AM fungal assemblages in the field. This project uses serpentine, a naturally toxic soil, to test the role of common root symbionts, arbuscular mycorrhizal fungi, in plant adaptation to extremely stressful soil environments. Broader impacts include contributions to taxonomy and education, and potential applications to conservation and bioremediation. Previously unknown fungal species are likely to be found associated with plants on serpentine soils. Undergraduate students and a PhD student will be trained in an important area of microbial biology. Collection and identification of fungi that are key components of a fragile, botanically important ecosystem could dramatically improve success of restoration efforts of locally endangered or rare species. Fungal species with unique physiological capabilities may be useful for bioremediation of toxic sites.