Sophie Mertha
Faculty Advisor: Jim Giovannoni
Year: 2021

“Metabolite Extractions from Tomato Fruit for Nutrient Composition and Gene Expression Analyses”

Project Summary:

Tomatoes are the world’s most important crop plant. According to the Food and Agriculture Organization, in 2019, 181 million tons of tomatoes were produced globally. Tomatoes have a relatively small genome and there is a great deal of information available about the genetic sequences of tomatoes. Tomatoes also have a relatively short generation time and are self-fertilizing with a homozygous genome, which makes it easy to study genetically identical plants and propagate them by seeds. All of these components make tomatoes an ideal model species. The major class of pigments underlying coloration in tomato fruit are carotenoids. Various fruit color phenotypes of tomatoes indicate different carotenoid profiles with contrasting levels of pigments, and this indicates different levels of carotenoid biosynthetic enzyme activity. The activity of these enzymes is what defines the accumulation of specific carotenoids, which results in the distinctive colors of tomatoes. Carotenoid biosynthesis genes are regulated at a transcriptional level. In order to determine the different accumulations of carotenoids, liquid chromatography is used to assess carotenoid profiles. These profiles can provide insight into the underlying genetic expression leading to differing accumulations of carotenoids in tomatoes. Once the carotenoid profiles are available, quantitative PCR can be performed to assess the expression levels of selected carotenoid biosynthesis genes. This will give us insight into which genes are responsible for the accumulation of certain carotenoids. With this information available, we have more knowledge about the genetic regulation of nutritious carotenoid profiles, which can be used to target the breeding of nutritious tomatoes.

My Experience:

Having this opportunity, to work in a lab and learn more about scientific research and plant biology, has been extremely helpful in giving me an idea of what I want to study and pursue in college. I really enjoyed working with a mentor and learning from her, whether it was basic yet complicated concepts that I’m not yet sure, I completely understand or small tricks to make lab work more precise and efficient, I really appreciated this experience. I was amazed by the vast amount of information that was available to me every day from the weekly lectures to seminars to overhearing conversations between people in the lab to the posters that are in every hallway. This internship has furthered my interest in scientific research and has given me much more insight into how scientific research is conducted and especially the importance of research in plant biology.