PT  - JOURNAL ARTICLE
AU  - B. Markus Lange
AU  - Brenton C. Poirier
AU  - Iris Lange
AU  - Richard Schumaker
AU  - Rigoberto Rios-Estepa
TI  - Organ-specificity of sterol and triterpene accumulation in <em>Arabidopsis thaliana</em>
AID  - 10.1101/2020.03.23.004358
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.03.23.004358
4099  - http://biorxiv.org/content/early/2020/03/25/2020.03.23.004358.short
4100  - http://biorxiv.org/content/early/2020/03/25/2020.03.23.004358.full
AB  - Sterols serve essential functions as membrane constituents and hormones (brassinosteroids) in plants, while non-sterol triterpenoids have been implicated in defense responses. Surprisingly little is known about the sterol and triterpene profiles in different plant organs. To enhance our understanding of organ-specific sterol and triterpene accumulation, we quantified these metabolite classes in four different organs (root, stem, leaf, seed) of Arabidopsis thaliana (L.). Based on these data sets we developed kinetic mathematical models of sterol biosynthesis to capture flux distribution and pathway regulation in different organs. Simulations indicated that an increased flux through the sterol pathway would not only result in an increase of sterol end products but also a concomitant build-up of certain intermediates. These computational predictions turner out to be consistent with experimental data obtained with transgenic plants ectopically overexpressing 3-hydroxy-3-methylglutary-coenzyme A reductase (HMG1 gene). The opportunities and limitations of incorporating mathematical modeling into the design of approaches to engineer sterol biosynthesis are discussed.