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A Customizable Approach for the Enzymatic Production and Purification of Diterpenoid Natural Products
Published on: October 4, 2019
Benzoxazinoid biosynthesis in dicot plants
Katrin Schullehner1, Regina Dick, Florian Vitzthum
1Lehrstuhl für Genetik, Technische Universität München, Am Hochanger 8, 85350 Freising, Germany.
Phytochemistry
|October 22, 2008
Summary
Benzoxazinoids, like DIBOA, are defense compounds found in grasses and some dicots. Their biosynthesis in dicots shares initial steps with grasses, involving indole and cytochrome P450 enzymes.
Area of Science:
- Plant biochemistry
- Chemical ecology
- Evolutionary biology
Background:
- Benzoxazinoids are crucial defense compounds in grasses, with sporadic occurrences in dicots.
- DIBOA (2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one) is the primary benzoxazinoid aglucon in studied dicots: Aphelandra squarrosa, Consolida orientalis, and Lamium galeobdolon.
- Benzoxazinoid distribution varies, being root-specific in A. squarrosa but present in above-ground organs of C. orientalis and L. galeobdolon.
Purpose of the Study:
- To investigate the presence and distribution of benzoxazinoids in specific dicot species.
- To elucidate the initial biosynthetic pathways of benzoxazinoids in dicots, comparing them to monocots (grasses).
- To explore the evolutionary aspects of key enzymes involved in benzoxazinoid biosynthesis, particularly indole-3-glycerolphosphate lyase.
Main Methods:
- Comparative analysis of benzoxazinoid content across different plant organs and species.
- Biochemical assays to identify key intermediates and enzyme activities.
- Phylogenetic and comparative genomics approaches to study enzyme evolution.
Main Results:
- DIBOA is confirmed as the main benzoxazinoid aglucon in A. squarrosa, C. orientalis, and L. galeobdolon.
- Benzoxazinoid presence differs significantly, with root-specific localization in A. squarrosa versus widespread above-ground distribution in C. orientalis and L. galeobdolon.
- The initial steps of benzoxazinoid biosynthesis, including indole formation via indole-3-glycerolphosphate lyase and subsequent oxygenation by cytochrome P450, appear conserved between dicots and monocots.
- Consolida orientalis possesses an indole-3-glycerolphosphate lyase that evolved independently from its maize ortholog.
Conclusions:
- Benzoxazinoid biosynthesis pathways show conserved initial steps across diverse plant lineages (monocots and dicots).
- The independent evolution of indole-3-glycerolphosphate lyase in C. orientalis highlights convergent evolution in plant defense compound pathways.
- Understanding these pathways provides insights into plant chemical defense strategies and evolutionary adaptations.
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