Joseph Dyson
Faculty Advisor: Jocelyn Rose
Year: 2018
School: Wells College

“The Initiation and Development of Trichomes on Developing Tomato Fruits”

Project Summary:

Tomato (Solanum lycopersicum) is a major food crop and each plant has tiny hairs called trichomes present on the stem, leaves, flower bud, and fruit. Not much is known about the genetics of tomato trichome initiation and development. To better understand trichome development in tomato fruit, numerous introgression lines (ILs) were observed throughout their development. These ILs are composed of a tomato variety (M82) which includes single introgressed genomic regions from the wild tomato relative, green-fruited species, Solanum pennellii. S. pennellii has a higher density of trichomes than the domesticated species M82 on all aerial parts. ILs that had higher densities of trichomes when compared to M82 were selected for further analysis. Genes, especially those transcription factors, in these introgressions were screened for high expression in epidermal tissue as these highly expressed genes are strong candidates for controlling trichome initiation and development. To analyze these candidate genes, Virus-Induced Gene Silencing (VIGS) was used to determine if silencing any of the individual genes would yield a phenotype with decreased trichome size or density. Light microscopy was also used to observe the trichomes on leaves and young ovaries in more detail. Stains of the ovaries were produced to more easily view the microscopic trichomes. Understanding more about trichome initiation and development in tomato fruits can prove to be beneficial for the agricultural success of tomato or improve the fruit’s marketability.

My Experience:

This 10-week experience was a wonderful opportunity for me to learn more about how research is conducted in the lab. I’ve learned techniques such as DNA/RNA extraction, primer design, bacterial chemical transformation, PCR, qPCR, gel electrophoresis, virus-induced gene silencing, and more. While I’ve learned about some of these techniques before, being able to utilize these techniques independently was an excellent learning experience. The most important skill I have learned is how to troubleshoot when an experiment fails. This was a skill I had trouble with at first but with help of my mentor Qian Shen and others in the Rose Lab, I am more confident in my abilities. I’ve learned so much this summer and being able to learn more about research in plant science was an amazing experience.