Date of Award

Spring 5-1-2020

Document Type

Honors Project

Degree Name

Bachelor of Science

Department

Biological Sciences

Department Chair or Program Director

Lewis, Lynn

First Advisor

Wynn, April

Second Advisor

Baker, Dianne

Third Advisor

Morriss, Ginny

Major or Concentration

Biology

Abstract

Uniform germination among crops produces greater yields at harvest. Understanding the mechanisms underlying seed performance could provide strategies to maximize agricultural efficiency and mitigate the effects of adverse climatic conditions. Seeds produced by Arabidopsis thaliana plants that have undergone drought stress have been previously shown to exhibit delayed germination. It has been posited that epigenetic inhibition of growth-promoting genes during gametophyte development could be the cause of this phenomenon. Such inhibition is likely mediated by methylation, a common epigenetic modification. In prior studies, seeds produced by drought-stressed plants have been shown to contain increased genome-wide methylation levels. This study aimed to determine if germination delay is associated with hypermethylation of genes expressed in seeds, and if either the male or female parent plant is disproportionately associated with these transgenerational effects. Reciprocal crosses were performed between drought stressed and control plants and within each treatment groups to create seeds with varying levels of parental stress. Germination delay was found in offspring of drought-stressed plants compared to control. Interestingly, germination occurred more quickly in offspring of a drought-stressed male parent with a control female parent compared to offspring of two control parents. Expression of Tryptophan Aminotransferase 1 (TAA1) was found to be lower in the offspring of drought-stressed plants, suggesting that TAA1 could be a possible target of epigenetic modification. There was no statistical difference in Early Responsive to Dehydration 10 (ERD10) expression between treatment and control offspring. Bisulfite converted DNA was produced for TAA1 and ERD10 for future studies into specific methylation sites in these gene.

Included in

Biology Commons

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