Senior Honors Projects, 2020-current

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Date of Graduation



Document Type


Degree Name

Bachelor of Science (BS)


Department of Biology


Jonathan Monroe

Timothy A. Bloss

Christopher E. Berndsen


Starch is a polymer of glucose that is used as an energy store in plants. Mobilization of starch has implications in abiotic stress survival and recovery. While the importance of carbon and energy allocation in plant survival has been explored, the specific roles of starch degrading enzymes in plant responses to stress are still unclear. β-Amylase3, or BAM3, is the principle starch degrading enzyme at night and is transcriptionally upregulated in response to cold stress in the plant Arabidopsis thaliana. Using single and quadruple knockout mutant plants, I aimed to clarify the role of BAM3 in the response to cold stress over a 96-hour period. The difference between starting cold stress in the morning versus at night were compared to clarify any differences in BAM3 activity, reducing sugars content, or starch accumulation that could have implications in cold stress survival or recovery. Recovery from cold stress was also monitored to verify if BAM3 plays an essential role in recovery from cold stress as hypothesized. I found that BAM3 activity declined over 60% after 96 hours in cold stress regardless of when cold stress started, reducing sugars steadily increased, and starch degradation is halted within the first 24 hours of cold stress. Also, my data does not support that BAM3 plays an essential role in the recovery from cold stress. Activity does not change significantly in the first 24 hours of recovery and appears to decline by hour 48 of recovery from cold stress.



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