Collin DeMan
DeMan, Collin
Year: 2022
Faculty Advisor: Li Li
Mentor: Sombir Rao

“Investigating the role of isopentenyl-diphosphate isomerase in regulating vegetative growth and biomass in Arabidopsis thaliana

Project Summary:

Plant architecture is greatly influenced by the number, size, and shape of the organs. Organ size is of great essence for agronomic yield and vegetative biomass production in plants. Recent studies highlight the involvement of carotenoid pathway genes in influencing biomass partitioning and fitness in plant. Carotenoids are a class of secondary metabolites produced by all photosynthetic organisms and serve as photosynthetic pigments, photoprotective agents, and precursors of phytohormones and signaling molecules. Carotenoid biosynthesis pathway begins with the synthesis of C5 isopentenyl pyrophosphate (IPP) and its isomer dimethylallyl pyrophosphate (DMAPP) via the methylerythritol 4-phosphate (MEP) pathway. The condensation of IPP and DMAPP forms geranylgeranyl pyrophosphate (GGPP), which serves as the precursor for the synthesis of various terpenoids, such as carotenoids, chlorophyll, and plastoquinones. IPP isomerase (IPI) is a key enzyme and catalyzes the interconversion of IPP and DMAPP. The ongoing study in our laboratory shows a correlation between IPI1 expression and plant growth in Arabidopsis thaliana. In this study, we analyzed the effects of IPI1 overexpression and ipi1 knockout in regulating vegetative growth and biomass production. IPI1 overexpression results in significantly enhanced vegetative growth, while ipi1 mutation reduces the plant growth and biomass. Interestingly, we found that IPI1 overexpression greatly increases DXS1 enzyme protein level and total carotenoid content. Moreover, IPI2 overexpression lines were created in order to determine whether IPI2 also affects vegetative growth and biomass production.

My Experience:

I have learned a tremendous amount about not only plant science, but professional-level research throughout my time working as an intern in the Li lab. Due to the pandemic, I was not able to participate too much in lab research in prior years, however, this REU allowed me to hone my skills and made me proficient in many useful lab techniques (PCR, RNA extraction, cell transformation, etc.) This hands-on process also allowed me to get a deeper understanding of the molecular mechanisms of these vital techniques, a useful skill when needing to troubleshoot protocols. Aside from purely lab techniques, I also experienced the collaborative nature of research and gained a significant amount of knowledge from not only my outstanding mentor but my peers as well. This experience has solidified my desire to pursue research as I continue into higher education.