Medicine and Health Sciences Commons^™

Mycorrhiza-Mediated Recruitment Of Complete Denitrifying Pseudomonas Reduces N2o Emissions From Soil, Xia Li, Ruotong Zhao, Dandan Li, Guangzhou Wang, Shuikuan Bei, Xiaotang Ju, Ran An, Long Li, Thomas W Kuyper, Peter Christie, Franz S Bender, Ciska Veen, Marcel G A Van Der Heijden, Wim H Van Der Putten, Fusuo Zhang, Klaus Butterbach-Bahl, Junling Zhang

Student and Faculty Publications

Background: Arbuscular mycorrhizal fungi (AMF) are key soil organisms and their extensive hyphae create a unique hyphosphere associated with microbes actively involved in N cycling. However, the underlying mechanisms how AMF and hyphae-associated microbes may cooperate to influence N2O emissions from "hot spot" residue patches remain unclear. Here we explored the key microbes in the hyphosphere involved in N2O production and consumption using amplicon and shotgun metagenomic sequencing. Chemotaxis, growth and N2O emissions of isolated N2O-reducing bacteria in response to hyphal exudates were tested using in vitro cultures and inoculation experiments.

Results: AMF hyphae reduced denitrification-derived N2O emission (max. 63%) …

Interactions Among Plants, Bacteria, And Fungi Reduce Extracellular Enzyme Activities Under Long-Term N Fertilization, Joseph E. Carrara, Christopher A. Walter, Jennifer S. Hawkins, William T. Peterjohn, Colin Averill, Edward R. Brzostek

Clinical and Translational Science Institute

Atmospheric nitrogen (N) deposition has enhanced soil carbon (C) stocks in temperate forests. Most research has posited that these soil C gains are driven primarily by shifts in fungal community composition with elevated N leading to declines in lignin degrading Basidiomycetes. Recent research, however, suggests that plants and soil microbes are dynamically intertwined, whereby plants send C subsidies to rhizosphere microbes to enhance enzyme production and the mobilization of N. Thus, under elevated N, trees may reduce belowground C allocation leading to cascading impacts on the ability of microbes to degrade soil organic matter through a shift in microbial species …

Influence Of Soil Microorganisms On Plant Growth And Fitness, Benjamin Jayne

Electronic Theses and Dissertations

Most terrestrial plants benefit from symbiosis with soil microorganisms. Symbiotic bacteria and fungi have wide-ranging effects on host plants, including improved nutrition, disease resistance, and drought tolerance. Association with Arbuscular Mycorrhizal Fungi (AMF) can enhance growth and protect plants from environmental stressors while they share products of photosynthesis with the resident fungi. Scores of studies indicate that mycorrhizal plants are more resistant to drought stress than their non-mycorrhizal counterparts. Use of microbes as a plant and soil supplement in home gardens represents a sustainable alternative to resource-intensive inputs and may allow for reduced water use. I investigated the effects of …