Marge Poma Alarcon
Poma Alarcon, Marge
Year: 2022
School: Smith College
Faculty Advisor: Olena Vatamaniuk
Mentor: Ju-Chen Chia

“Transcriptional regulation of the crosstalk between iron (Fe) and copper (Cu) homeostasis”

 Project Summary:

Copper (Cu) and iron (Fe) are essential micronutrients for plant growth and reproduction. Plants balance the beneficial and toxic effects of these minerals and tightly control Fe and Cu uptake from the roots. Crosstalk between Cu and Fe homeostasis in Arabidopsis thaliana has been documented and includes Cu accumulation under Fe deficiency and vice versa. However, the molecular components of the crosstalk in Fe accumulation under Cu deficiency and how it is regulated are not well understood. It is known that at least 10 bHLH transcription factors regulate Fe deficiency response, while CITF1 (Cu-deficiency-induced transcription factor 1, bHLH160) is highly activated in Cu deficiency response to regulate Cu-deficiency responsive genes. Recently, CITF1 and a bHLH family members that responds to Fe deficiency, named CITP (CITF1-interacting protein), were identified and interact with each other in vivo, which suggest a novel pathway of the crosstalk between Cu and Fe homeostasis. This protein complex is found to be stabilized by Cu deficiency, and the CITF1 knock-out mutant, citf1, accumulates significantly less Fe under Cu deficiency. However, CITF1 does not regulate the genes encoding the major Fe uptake system in the roots. These data suggest that CITF1 and/or CITF1-CITP protein complex regulate an alternative Fe uptake pathway under Cu deficiency. In order to facilitate the study of the transcriptional crosstalk of Fe and Cu deficiency responses, the citf1 cipt double knock-out mutant will be generated and ChIP-sequencing will be performed to identify the direct gene targets of CITF1-CITP protein complex.

My Experience:

I came into this internship with little to no experience in molecular biology research, as I’ve only had experience in plant ecology and field work back in my home institution. Because of this, I felt there was a huge learning curve in picking up new laboratory skills and independently working on my project, but I quickly realized it’s okay to make and correct mistakes made early on. Not only did I learn new plant-specific protocols like hydroponic set-up, RNA extraction, qPCR analysis, and chromatin immunoprecipitation, I also gained a deeper appreciation of plant biology research not just for conservation but also for agriculture. My colleagues had open conversations about graduate school and the PGRP provided lots of networking opportunities.

I’m happy to say I’ve gained confidence in the ability to conduct research outside my field and feel more prepared in pursuing a graduate degree in the near future!