Anisabel Guzman
Faculty Advisor: Jim Giovannoni
Year: 2021

“Identifying the Genetic Loci Contributing to Folate Accumulation in Tomato”

Project Summary:

Folates are one of the most important vitamins found in food. They serve as co-factors in the synthesis of DNA, methionine, and amino acids. While plants and microorganisms can synthesize folates, humans cannot. A deficiency in folate can lead to adverse health problems such as cardiovascular disease, anemia, dementia, and neural tube birth defects. Leafy greens are main contributors of folate, while most fruits are poor sources. Many countries fortify foods with synthetic folic acid. However, too much synthetic folic acid can be detrimental and cause health risks. Folate biofortification is an alternative way to increase natural folate in crops and diversify dietary sources of folate. This project focused on understanding the basis of folate accumulation in tomatoes, an economically and nutritionally important fruit. The Solanum pennellii introgression lines, which contain a genetically mapped, single introgression from S. pennellii in the genetic background of the domesticated tomato cv. M82. were previously accessed for genetic variation of folate content, and the expression of folate biosynthetic genes. Lines were chosen based on this information for pyramiding, to find crosses that resulted in higher folate and elucidate the causal gene(s) for the increased folate. Fruit folate levels were measured in two F3 populations using a microbiological assay. The results showed variation in folate content and were correlated with prior genotyping data. This also showed folate accumulation as a complex trait.  F2 lines, derived from a backcross between M82 and lines showing significant amounts of folate, were genotyped with genetic markers, and grown in the field. This will be a great resource for fine mapping the gene for folate accumulation and will be useful in the folate biofortification effort.

My Experience:

This program allowed me to understand and gain experience in a lab setting. Getting to meet and work with my mentor helped me really grapple with the idea of potentially going into research for graduate programs or possible future careers. Over the course of this summer, I have been able to be more confident and comfortable with conducting my own research. Getting to work with the many people at Boyce Thompson and the Giovannoni lab was an amazing experience because they were able to help me go in a direction that could benefit me in the long run. This program helps you understand the importance of plant biology and the many available career choices. It is one of the biggest research fields to work in and this program does a great job at describing it. After this program I plan on working in the plant biology field to gain more experience and find my way into areas that I would enjoy working long term.