Stephen Yang
Year: 2022
Faculty Advisor: Jim Giovannoni

“Exploring the Role of Ethylene in Transcriptional Regulation of the Melon Carotenoid Pathway”

Project Summary:

Ethylene is a phytohormone emitted by certain fleshy fruits and a key regulator of ripening in crops such as tomato, melon, banana, and pear. Ethylene’s role has been particularly well defined in the ripening process of tomato. In addition to the release of ethylene, an important parameter of ripening is the evolution of fruit color. In particular, carotenoid pigments are compounds integral to plant development and fruit quality, mediating both flavor and aroma and fulfilling roles as dietary antioxidants that lower blood pressure and help prevent heart disease (Lewinsohn et al 2005). In tomato, ethylene upregulates the expression of ripening-related transcription factors which collectively regulate the biosynthesis of carotenoids (Li et al 2019). While tomato offers a model organism tractable to genetic analysis, many fruit crops display variation across ethylene-dependent ripening systems. An example of this variation is evident in melon, where different varieties exhibit a range of climacteric and non-climacteric phenotypes. Accordingly, the role of ethylene in regulating the ripening process of melon is an area under active investigation, as the operation of the melon carotenoid pathway during ripening has only been broadly characterized compared to tomato, where the regulation of this pathway has been described in greater mechanistic detail. In particular, it remains uncertain as to why ethylene emissions and fruit carotenoids appear to operate independently during melon ripening (Guis 1997), whereas both processes are coupled in tomato. Our research hopes to clarify the applicability of ripening discoveries in tomato and further explore carotenoid biosynthesis in melon.

My Experience:

This internship gave me an opportunity that is hard to come by as a high schooler. I was able to work in a lab environment, learn about experimental design, and work with experienced scientists every day. I especially valued the nature of the mentor-mentee experience where I could ask questions about the smallest details of a procedure and expect support and guidance. I would also like to recognize the collaborative educational atmosphere at BTI. From weekly seminars to casual conversations with other interns and members of faculty outside of my lab, there was always an opportunity for learning. This experience has greatly expanded my knowledge of plant biology and shown me, in part, how scientific research is conducted.