Metabolic Tracing and Quantification of β‐Alanine in Wheat

There are few plants that come close to having the same global importance as wheat. While mainly grown in the middle latitudes and northern hemisphere, the growth range of wheat nearly encompasses the entire globe. As a grain, wheat provides essential phytochemicals and dietary fiber for the human diet in addition to vitamins, minerals, and nutrients. Due to its widespread relevance, wheat was chosen as a system to study the synthesis of β‐alanine, a key precursor for the synthesis of vitamin B5 (pantothenate) and subsequently coenzyme A, which is an essential coenzyme in lipid and carbohydrate metabolism. While the synthesis of β‐alanine is well characterized in bacterials systems, it is less so in plants. Currently the proposed precursors include polyamines, uracil, and propionate and appear to be plant‐specific. Recent data from our lab suggests that β‐alanine can be synthesized from isoleucine via the propionyl‐CoA pathway in the model plant Arabidopsis thaliana . To determine whether this proposed pathway is plant‐specific, we investigated the metabolic profiles of wheat seedlings as a proxy for monocotyledon plants using gas chromatography‐mass spectrometry (GC‐MS). β‐Alanine was found in lower amounts than in Arabidopsis , however, subsequent metabolic tracing studies using 13 C‐labeled precursors showed that wheat synthesized β‐alanine from both isoleucine and propionate as seen in Arabidopsis . While other proposed synthetic routes seem to be plant specific, these findings not only support the hypothesis that isoleucine functions as a precursor in the synthesis of β‐alanine but also that it also occurs in both monocotyledon and dicotyledon plants. Support or Funding Information Kenyon Summer Science Scholars Program This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .