SSRP Abstract

Board 13: The Influence of Nitrate Reductases on Gravitational Response in Arabidopsis thaliana

Student Scientist: Carly Sanders ’24
Research Mentor: Chris Wolverton (OWU Department of Biological Sciences)

Before plants are able to use nitrogen, an essential nutrient, they must first change its form. Two genes in Arabidopsis thaliana are known to be key players in the first steps of this process but are also thought to be involved in an alternative gravity response pathway. By using plants that are confirmed to have a non-working copy of these genes, it can be determined if and how these genes are interacting with gravity. These results can be used to understand how plants respond to gravity, which will contribute to the ability to grow plants in environments with lesser gravity, such as in space.

Nitrate reductase is an enzyme that plays an important role in nitrogen assimilation. It also provides a source of nitric oxide, which helps plants regulate growth and respond to stress. In Arabidopsis thaliana, two nitrate reductase genes, NIA1 and NIA2, are also believed to be involved in the plant’s response to gravity. Both genes show gravity-dependent changes in transcript abundance as measured by RNA-seq analysis of the early-stage gravity response in root tips. In order to determine if and how these genes play a role in the gravity sensing pathway, mutant seeds with specific T-DNA inserts were used to disrupt the working copy of the gene of interest. Each mutant line of seeds was confirmed to contain its T-DNA insert through PCR based on DNA isolated from corresponding mutant Arabidopsis seedlings. Gravity response experiments were performed to determine whether there was a difference in phenotype between the mutant seedlings and the wild-type seedlings. The results of this research are yet to be determined. In addition, further research is needed to determine in what way nitrate reductase and nitric oxide are specifically involved in the gravitational response.