Folates/Vitamin B9 are indispensable for life. Deficiency of folates in humans causes diseases, like neural tube defects and megaloblastic anemia. Folates are biosynthesized only in plants and microorganisms, and thus humans majorly rely on plants for their folate needs. As staple crops like cereals are folate deficient, folate biofortification is a solution to meet the need of poor regions worldwide, where other strategies fail to function. Global efforts led to enhancement of folates in several species, including rice (by our lab), but two major issues that impede desired results are projected. (1) Tissue-specific resistance exerted by plants to maintain folate balance, and (2) repercussions associated with its enhancement. This highlights the dire need to fully understand folate metabolism and how it modulates plant development. Folates comprise different tetrahydrofolate (THF) derivatives, functioning in C1 metabolism. 5-formyl(F)-THF is an enigmatic form, as it does not seem to function in C1 metabolism, and studies focusing on its function are missing. We identified 5-F-THF binding proteins in Arabidopsis, revealing its interactions with different important metabolic pathways, including nitrogen (N) metabolism. This project aims at studying the regulatory role of 5-F-THF in plants and elucidating its link to N metabolism. This will help in fine-tuning biofortification strategies and may offer ways to improve N assimilation efficiency in plants.