Plants live in tight association with microbes, especially belowground where fungi and bacteria live on and inside the roots of plants. The relationship can be beneficial or harmful to the plant. Some microbes cause plant diseases by decomposing roots. Others trade nutrients with the roots in return for sugars produced aboveground by leaves.
We investigate two main aspects of the relationship between plants and microbes in the soil. First, as it pertains to weeds, we want to know if soil microbes can help or hinder plant invasions. Three highly invasive weeds of contrasting life history strategies; cheatgrass, knapweed and leafy spurge, co-occur with remnants of native plant vegetation. This creates a unique opportunity to observe, characterize, and manipulate interactions between plants and belowground microbial communities. We outline a number of short, intermediate and long-term research projects that will significantly enhance our knowledge regarding plant microbe interactions and soil processes, with the overall goal to better understand, predict and counteract plant invasions, and to restore and manage invaded ecosystems.
Second, we seek to understand how the relationship between plants and soil influences the function of ecosystem processes. Soil microbes are responsible for organic matter decomposition and nutrient cycling between the atmosphere and the land. On this project we collaborate with the Earth Microbiome Project (EMP). The goal is to map and understand the diversity of microorganisms in habitats around the world. We mapped microbial diversity and function across gradients of weed invasions.
In May 2019, we sprayed hundreds of western white pine seedlings with an experimental fungal microbiome. This effort was part of a greenhouse experiment to determine how fungi can influence disease caused by the blister rust pathogen, Cronartium ribicola.
On September 19th, 2019, seedlings were exposed to C. ribicola spores in the fog chamber (above), at the Dorena Genetic Resource Center in Eugene, OR. Hundreds of Ribes leaves naturally infected with the blister rust pathogen (below), were used to spread disease to the seedlings.
Leaves were placed spore-side down on racks above white pine seedlings (above). Artificial fog induces the release of spores to increase pathogen infection. A subset of seedlings was destructively sampled to determine the success of our May inoculations. We will have results of that analysis later this fall.
Lorinda Bullington comes from three generations of small-scale Montana loggers, or as her grandfather put it, "the first environmentalists.” Not wanting to leave this beautiful state, Lorinda attended the University of Montana, earning a B.S. in Microbiology in 2010. Family traditions inspired a love of forests and nature, and during her junior year of college, Lorinda began working at MPG North, studying microbial communities associated with Western white pine trees and how those microbes can influence tree health and deer browse in forest ecosystems.
After college, Lorinda continued this line of research, working full time at MPG Ranch. She experimentally inoculated plants with microbes, in the field, and in the greenhouse, to enhance ongoing restoration projects and learn more about plant-microbe interactions. This lead to follow up studies exploring microbial communities associated with five-needle pines in relation to tree physiology, genetics, and disease resistance. Through this research, Lorinda recently earned an M.I.S. degree at the University of Montana, focusing on plant molecular ecology. At MPG Ranch she is involved in both original research and bioinformatics, combining biology and computer science to better interpret molecular data. When not working, Lorinda enjoys going to the gym, gardening and getting outside.