Date of this Version
Guo, A. 2023. Exploring Gene Expression Patterns for Resilient Maize Lines Under Nitrogen Stress. Undergraduate Honors Thesis. University of Nebraska-Lincoln.
Nitrogen plays a major role in the proper growth and development of maize and is therefore essential to crop production, being the most critical nutrient for achieving optimal yield. In previous field and greenhouse studies, we have found maize lines that differ in their resiliency to nitrogen stress. To identify the potential genomic regions associated with the differences in nitrogen deficiency resilience, Genome-Wide Association Studies (GWAS) were conducted. Based on a previous study, the most consistently resilient maize inbred lines within the Goodman-Buckler diversity panel have been identified as the lines A619 and A661, while the non-resilient inbred lines have been identified as the lines NC368 and B84. However, we still do not know why these specific lines are more resilient to nitrogen stress. From these analyses, we have a list of potential genes that can help us understand their role in nitrogen stress response. Using this list of potential genes, we narrowed down ten total candidate genes to design primers to be tested. In order to test these primers, we grew both nitrogen stress resilient (A619 and A661) and non-resilient (NC368 and B84) maize lines in the greenhouse under two different nitrogen treatments, Hoagland full nutrient solution and Hoagland solution with only 20% nitrogen. RNA was then collected from the leaf, root, shoot apical meristem (SAM), and developing inflorescences at various developmental time points from each of the resilient and non-resilient maize lines. Reverse transcription-polymerase chain reaction (RT-PCR) was performed using primers designed for genes previously identified from the GWAS that are also known to be expressed in roots, SAM, and/or inflorescences in order to better understand the potential role of these candidate genes in resilience to nitrogen stress throughout plant growth and development.
Nitrogen, Maize, Genome-Wide Association Studies (GWAS), Reverse transcription-polymerase chain reaction (RT-PCR)