Salty Beans: The Effects of Moderate Salt Stress on Nodule Formation in Medicago truncatula
Conference Year
January 2020
Abstract
Nitrogen is the most limiting resource for plant growth. Legumes have evolved a symbiosis with a soil bacterium that converts atmospheric nitrogen into a plant available form. This symbiosis involves chemical communication, coordinated growth, and the creation of a new root organ, the nodule. Previous research has shown that this symbiosis is particularly sensitive to salt stress, resulting in dramatic reductions in nodulation, even at levels that do not significantly reduce plant biomass. I investigated the underlying cause of this reduction and will determine if it is a result of reduced initiation of nodules, disrupted or abnormal development, or both. Plants were grown in a controlled environment, in a defined medium, with the treatment group receiving 100mM NaCl. Roots were harvested 7 days post-bacterial-inoculation and stained using a modified Pseudo-Schiff method. Data was gathered via whole-mount, confocal scanning laser microscopy, which allowed for faster and more accurate data collection. Using previously defined stages of nodule primordia development, I categorized each nodule primordia across treatments. In this way, I intend to determine if there is a significant reduction in the number of initiated nodules, significant differences in the distribution of nodule stages, and if there is any abnormal development across treatments.
Primary Faculty Mentor Name
Jeanne Harris
Faculty/Staff Collaborators
Jeanne Harris
Status
Undergraduate
Student College
College of Agriculture and Life Sciences
Program/Major
Plant Biology
Second Program/Major
Sustainable Landscape Horticulture
Primary Research Category
Biological Sciences
Salty Beans: The Effects of Moderate Salt Stress on Nodule Formation in Medicago truncatula
Nitrogen is the most limiting resource for plant growth. Legumes have evolved a symbiosis with a soil bacterium that converts atmospheric nitrogen into a plant available form. This symbiosis involves chemical communication, coordinated growth, and the creation of a new root organ, the nodule. Previous research has shown that this symbiosis is particularly sensitive to salt stress, resulting in dramatic reductions in nodulation, even at levels that do not significantly reduce plant biomass. I investigated the underlying cause of this reduction and will determine if it is a result of reduced initiation of nodules, disrupted or abnormal development, or both. Plants were grown in a controlled environment, in a defined medium, with the treatment group receiving 100mM NaCl. Roots were harvested 7 days post-bacterial-inoculation and stained using a modified Pseudo-Schiff method. Data was gathered via whole-mount, confocal scanning laser microscopy, which allowed for faster and more accurate data collection. Using previously defined stages of nodule primordia development, I categorized each nodule primordia across treatments. In this way, I intend to determine if there is a significant reduction in the number of initiated nodules, significant differences in the distribution of nodule stages, and if there is any abnormal development across treatments.