Characterizing Effects of Ala-Ile Dipeptide on Arabidopsis Germination and Growth

Plant regulation of carbon metabolism is a central focus of plant biology as a whole, as it has far-reaching implications regarding how plants react to environmental stimuli; this in turn has applications to fields ranging from herbicides to crop resilience. Regulation is often achieved by small-molecule inhibition of key carbon metabolism enzymes, allowing products of catabolism to directly regulate plant cells’ carbon cycles. One recent example is proteogenic dipeptides, which co-elution studies have shown associate, possibly in an inhibitory capacity, with a number of essential carbon cycle proteins. My work focused on the in vivo interaction of PhosphoEnolPyruvate CarboxyKinase in Arabidopsis thaliana (AthPEPCK1) with the Alanine-Isoleucine(Ala-Ile) dipeptide. The interaction of these has already been reported by Moreno et al. (2021) in an assay that showed Ala-Ile inhibited AthPEPCK1 activity; this was directed by an initial study by Veyel et al. (2018) on co-elution of various metabolic proteins. AthPEPCK1 is an important enzyme in the process of gluconeogenesis, where glucose is generated from pyruvate. Because gluconeogenesis is a highly upregulated process in germinating Arabidopsis seedlings, we anticipated that Ala-Ile exposure during seed germination would disrupt the process and produce a non-standard phenotype. As such, we conducted five weeklong germination and root growth assays. We utilized a Smart Plate Imaging RObot (SPIRO) to autonomously track germination and root growth on media plates in collaboration with Dr. Magdalena Julkowska. The inhibitory effect of Ala-Ile on plant growth in wild-type Arabidopsis seedlings was observed, but no significant effect was observed on germination.

Overall, this experience was a very positive learning experience for me with regards to phenotyping and bench work. My undergraduate research thus far has mainly been in computational fields, with my bench experience coming solely from various class-associated labs. As such, this REU gave me the opportunity to put techniques that I had learned to practical use, while also gaining knowledge in the fields of plant biochemistry and biology. This has helped me in rounding out my laboratory skills while contributing meaningfully to my lab’s research. This experience also gave me the opportunity to work with amazing scientists, and understand what the day-to-day work of a graduate student entails. The conversations I was able to have with them have allowed me to better plan out my own post-undergraduate path. Through this REU at BTI, I have become a more well-rounded researcher, and more confident about my future path.