Elucidating the Interactions between Melatonin, Indole-3-Acetic Acid, and Gibberellin in _Arabidopsis thaliana_ Development through Gene Expression Analysis

Authors

Sadie Gaskins, Harding UniversityFollow

Document Type

Thesis

Date of Completion

4-2024

Academic Year

2023-2024

Department

Biology

Academic Major

Molecular and Cellular Biology

Faculty Advisor

Rebekah Rampey, Ph.D.

Abstract

Several phytohormones regulate Arabidopsis germination, including abscisic acid (ABA), gibberellin (GA), indole-3-acetic acid (IAA) and melatonin (MT). These phytohormones contribute to efficient, timely germination, which allows for optimal crop yield. To examine the effect of MT on Arabidopsis germination, a germination assay was conducted with wild-type and auxin-deficient seeds. Percent germination was decreased in wild-type and increased in auxin-deficient seeds with MT treatment. To examine genetic interactions between IAA, GA, and MT during germination, RNA was isolated from wild-type and auxin-deficient seeds that were treated with IAA or MT. Transcriptional analysis was conducted with quantitative PCR to observe how treatment with different hormones affected MT, ABA, and GA biosynthesis and regulatory gene expression in both wild-type and auxin-deficient seeds. MT biosynthesis gene expression was higher in auxin-deficient seedlings compared to wild type, but was decreased in both groups when treated with IAA. GA biosynthesis and ABA regulatory gene expression was decreased in wild-type and auxin-deficient seeds treated with MT. This work demonstrates diverse roles for MT in Arabidopsis germination, including a possible compensatory role for MT in the auxin-deficient mutant. Future transcriptional analyses may provide further insight about the interactions between ABA, GA, IAA, and MT and how these hormones coordinately function during plant development. Knowledge of these interactions will be useful in general plant research as well as agricultural research.

Recommended Citation

Gaskins, Sadie, "Elucidating the Interactions between Melatonin, Indole-3-Acetic Acid, and Gibberellin in _Arabidopsis thaliana_ Development through Gene Expression Analysis" (2024). Honors Theses. 29.
https://scholarworks.harding.edu/honors-theses/29