Discipline: Biological Sciences
Subcategory: Plant Research
Cierra J. Wilson - Tuskegee University
Plants produce several sterols, which accumulate preferentially in different organs.
However, there is a gap in our knowledge about the regulation of sterol metabolism in plants, and the role of sterols in crop stress physiology. Fluctuations in the content of sitosterol and stigmasterol during development and conditions of stress suggest that these sterols modulate plasma membrane components, or signaling activities essential for plant development and stress compensation. From the human health standpoint, stigmasterol reduces the absorption of intestinal cholesterol and helps prevent heart disease. The overall objective is to understand how sterol metabolism is regulated in Arabidopsis thaliana, including the physiological function of genes controlling the conversion of sitosterol to stigmasterol. There is a growing interest globally in research to mitigate the impact of climate change on agriculture. Therefore, the findings from this research can benefit efforts to enhance stress tolerance and nutritional quality of maize by genetic or transgenic approaches. The specific objectives to achieve the overall objective are: (1)
To determine a relationship between stigmasterol and flowering rates in Arabidopsis thaliana, (2) To assess the relationship between the number and size of rosette leaves in plants with altered stigmasterol content, (3) To optimize qPCR assay to evaluate gene expression in plants with altered stigmasterol content, (4) To quantify mRNA for selected flowering genes.
These results were achieved using Wild Type Arabidopsis thaliana as the control and five other genotypes of Arabidopsis thaliana seeds. There are two restored and two overexpressed lines along with a mutant genotype. These contain altered levels of stigmasterol were used to measure the experimental findings. The Arabidopsis thaliana plants were grown in short day chambers, tissue sampled at 14 days, used for RNA extraction and qPCR analysis.
The data collected derived from six different Arabidopsis genotypes. The plants had difficulty growing, which caused some genotypes to look smaller than expected. The
Arabidopsis plants grown under short-days did not flower as expected and therefore difference in flowering time could not be determined. The difficulty in maintaining healthy plants, affected the diameter and number of rosette leaves across all genotypes. The qPCR optimization was successful for fatty acid amide hydrolase (FAAH) and the optimization was not completed for the other two genes flowering locas T(FT) and SEPPATALLA3(SEP3). Quantification of mRNA in different genotypes did not reveal differences in FAAH expression. The experiment would need to be repeated to verify the findings made and seeing how the results would vary on healthily grown Arabidopsis thaliana.Not Submitted
Funder Acknowledgement(s): The George Washington Carver Summer Internship Program 2017
Faculty Advisor: Dr. Walter Suza, firstname.lastname@example.org
Role: The Arabidopsis thaliana plants were grown in short day chambers, tissue sampled at 14 days, used for RNA extraction and qPCR analysis.