Conifers are an important part of the forest industry and are extensively planted for timber production. However, high crop yield demands and increasing environmentally stressful conditions such as heat, drought, and water salinity have caused an increase in the use of chemical fertilizers and water, which can be expensive and unsustainable. A possible alternative to fertilizers is the use of nitrogen fixing endophytes. Endophytes are bacteria or fungi that live within a plant, establishing a mutualistic relationship in which they can provide growth stimulation through production of growth hormones, nitrogen fixation, enhanced nutrient uptake, and protection from potential pathogenic colonizers. Prior studies have demonstrated that the use of fungal and nitrogen fixing endophytes significantly increases growth in many crop plants grown in the presence of abiotic stresses. In this study I have inoculated Douglas Fir seedlings with various strains of nitrogen fixing endophytes. Because confirmation of inoculation is essential, some of these endophytes were marked with a fluorescent marker (GFP) to confirm inoculation using fluorescent microscopy. Once inoculation was confirmed, conifers were grown in nitrogen-free or nitrogen-low soils and solutions to compare growth and measure nitrogen levels in plant tissues between inoculated and uninoculated conifers. If these endophytes prove to be beneficial for increasing conifer growth, they could be used as a sustainable alternative to chemical fertilizers and in turn, aid in the mitigation of climate change on forestry ecosystems and the environment.

Every plant needs Nitrogen to grow. Nitrogen is usually given through synthetic fertilizer which is expensive and causes a lot of environmental problems. Synthetic fertilizer is bad for the envieronment not only it need a lot of fossil fuel to make the high temperature and pressure condition for Nitrogen reaction, but also excess Fertilizer will bring blooming algae to the surround ponds, which will make the organism in the water die out because lack of Oxygen since the sunshine cannot get through algae and help underwater plants to photosynthesis. Since previous research in the lab showed that endophytes isolated from Willow and Poplar trees can promote growth of crops such as pepper, tomatoes, and sweet corn under low nitrogen conditions, we hope that Endophyte can reduce or completely substitute synthetic fertilizer of other commercial plants, such as corn. Endophytes (microbes living inside plants) can produce phytohormones and provide fixed nitrogen for plants. My research focuses on corn, a bioenergy crop species typically grown with large inputs of fertilizer. I screened ten commercial varieties of corn and compared the growth of endophyte inoculated plants with the uninoculated controls, in low nitrogen soil. In one variety of corn there was increased biomass in the inoculated plants compared to the controls. Currently I am testing which isolate is responsible for the plant growth promotion. These findings will have a great impact on commercial production of corn in a sustainable way.

Previous research done in our lab found that poplar and willow trees grow in nutrient-poor soil, and they obtain their nutrients through partnership with microbes that live within them (referred to as Endophytes). We then have successfully isolated endophytes and are now exploiting them for plant growth promotion, stress tolerance. My research question is to test if inoculating poplar clone OP-367 with endophytes can help the plant survive drought condition. The experiment was set up by controlling watering schedule that simulate drought condition and compared the results of the uninoculated control group and the inoculated group. We quantified the results using measurement of wet and dry biomass, chlorophyll (SPAD readings) which quantifies the health of the plant by measuring the greenness, and maximal photochemical efficiency (Fv/Fm), which quantifies the photosynthesis happening in the plant. The implication of this project will permit better growth of plants under water stress condition. The potential of endophytes to increase drought tolerance in OP-367 poplar hybrid and or other plant species can become a potential remedy for rescuing agriculture problems in relation to drought weather condition.