"Exploiting Evolutionary Diversification of Primary Metabolic Enzymes"

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Thursday 21 February 2019, 11:00 - 12:30

 
ABSTRACT

Plants synthesize numerous specialized metabolites that are critical for plant adaptation and human health. In contrast to well-documented diversification of specialized metabolic enzymes, relatively little is known about the evolution of primary metabolic enzymes that provide precursors to downstream specialized metabolic pathways. Combining evolutionary biochemistry, structure-function, and molecular genetic analyses, we recently uncovered lineage-specific diversification of the biosynthetic pathway of L-tyrosine (Tyr)—an aromatic amino acid required for synthesis of proteins and numerous plant natural products (e.g. vitamin E, dopamine, morphine). Unlike Arabidopsis thaliana having a tightly regulated plastidic Tyr pathway, legumes have an additional cytosolic pathway to synthesize Tyr. Independently, de-regulated Tyr biosynthetic enzymes evolved at the base of the core Caryophyllales (e.g. beet, cactus), which subsequently facilitated the evolution of diverse specialized metabolic pathways derived from Tyr, such as biosynthesis of betalain pigments and catecholamines. Introduction of these natural enzyme variants or underlying mutations in heterologous plant hosts led to elevated accumulation of Tyr and Tyr-derived compounds. I will discuss how primary and specialized metabolic pathways evolved coordinately in a macroevolutionary scale and how primary metabolic diversity can be exploited to build plant chemical production platforms, on which various natural product pathways can be reconstructed.

Location Jozef Schell Seminar Room
Contact Dr Hiroshi Maeda
Department of Botany
University of Wisconsin
Madison
USA