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Biology subjects

Lange, B. M.

Publications and source records attributed to Lange, B. M..

2 recordsLinked to original sources

High contribution of canopy to oleoresin accumulation in loblolly pine trees

The shoot system of all loblolly pine (Pinus taeda L.) contains abundant resin ducts, and the oleoresins contained within them have demonstrated roles in constitutive defenses. This study is providing a quantitative assessment of oleoresin biosynthesis and accumulation in resin ducts. Morphometric analyses of representative tissue sections indicate that the fractional volume of resin ducts is particularly high in the cortex of young stems and their needles, representing a major portion of total pine resins from primary growth of the canopy. We demonstrate that it is possible to extrapolate oleoresin formation from the microscopic scale (tissues sections) to the macroscale (entire trees), which has implications for assessing resins as renewable feedstocks for bioproducts.

plant biology

Organ-specificity of sterol and triterpene accumulation in Arabidopsis thaliana

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.

plant biology