Enhancing Plant Vitamin B6 Production by Increasing Levels of a Natural Arabidopsis Enzyme
Rebecca Wong
Department of Biology
Faculty Supervisor: Zheng-Hui He
Vitamin B6 (B6) is an essential cofactor required for the growth and metabolism of all living organisms, yet it can only be synthesized by plants, bacteria, archaea, and fungi. Previous efforts to enhance B6 content in crops have focused on increasing expression of Arabidopsis thaliana PDX1, a key enzyme in the de novo biosynthesis of the active vitamer pyridoxal‑5‑phosphate (PLP). However, these strategies yielded only modest increases in B6 levels, suggesting that homeostatic mechanisms tightly regulate PLP accumulation. Our lab has identified aminotransferase proteins as potential PLP sequesters, functioning as PLP‑binding reservoirs within the cell. Building on this model, I hypothesize that overexpressing the aspartate aminotransferase ASPARTATE AMINOTRANSFERASE 2 (ASP2) will increase PLP storage capacity and thereby elevate overall B6 accumulation in Arabidopsis. To test this, I generated transgenic plants overexpressing ASP2 cDNA using Agrobacterium‑mediated transformation. Screening confirmed 24 successful transformants, all of which displayed normal growth, root development, and seed production. This work provides a platform for studying mechanisms of PLP homeostasis and serves as a foundation for engineering B6‑enriched crops with improved nutritional value.