Effect of Melanin and Melatonin on Fe Acquisition, Chlorophyll, and Anthocyanin Concentration in Arabidopsis thaliana Col-0

Abstract

Iron (Fe) affects several physiological functions such as vital enzymes such as cytochromes in the electron transport chain which is necessary for overall plant growth. Most humans get their Fe from plant-based food, but it can be challenging to increase the amount of Fe in plants because of its toxicity and limited solubility. Fe deficiency can harm plant development, reduce production, and lower nutritional quality, adversely impacting human health. The effects of the oxidized L-DOPA (melanin) and melatonin on Fe uptake would be assessed using Arabidopsis thaliana Col-0 as a model organism using the two metabolites as post-germination treatment for the plants for seven days. According to previous studies, L-DOPA and melatonin have properties that could increase Fe uptake in plants by activating Fe deficiency-inducible genes. However, L-DOPA is unstable at high pH due to oxidation; the oxidized derivative effect towards Fe uptake would be analyzed in this study. Treated and untreated plants would be compared in terms of gene expression, plant mass, chlorophyll, and anthocyanin content. The experiment conducted showed that melatonin enhanced Fe acquisition slightly but also might make plants more sensitive to pathogens and inhibit plant growth. Meanwhile, melanin does not improve Fe uptake, and its high concentrations hinders RNA extraction, preventing gene expression analysis. For future studies, improvements could include using lower metabolite concentrations, increasing the number of replicates, and investigating the underlying mechanisms of melatonin and melanin effects on Fe uptake in A. thaliana Col-0.