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Introduction of chemically labile substructures into Arabidopsis lignin through the use of LigD, the Cα-dehydrogenase from Sphingobium sp. strain SYK-6
- Source :
- Plant biotechnology journal. 13(6)
- Publication Year :
- 2014
-
Abstract
- Bacteria-derived enzymes that can modify specific lignin substructures are potential targets to engineer plants for better biomass processability. The Gram-negative bacterium Sphingobium sp. SYK-6 possesses a Cα-dehydrogenase (LigD) enzyme that has been shown to oxidize the α-hydroxy functionalities in β-O-4-linked dimers into α-keto analogues that are more chemically labile. Here, we show that recombinant LigD can oxidize an even wider range of β-O-4-linked dimers and oligomers, including the genuine dilignols, guaiacylglycerol-β-coniferyl alcohol ether and syringylglycerol-β-sinapyl alcohol ether. We explored the possibility of using LigD for biosynthetically engineering lignin by expressing the codon-optimized ligD gene in Arabidopsis thaliana. The ligD cDNA, with or without a signal peptide for apoplast targeting, has been successfully expressed, and LigD activity could be detected in the extracts of the transgenic plants. UPLC-MS/MS-based metabolite profiling indicated that levels of oxidized guaiacyl (G) β-O-4-coupled dilignols and analogues were significantly elevated in the LigD transgenic plants regardless of the signal peptide attachment to LigD. In parallel, 2D NMR analysis revealed a 2.1- to 2.8-fold increased level of G-type α-keto-β-O-4 linkages in cellulolytic enzyme lignins isolated from the stem cell walls of the LigD transgenic plants, indicating that the transformation was capable of altering lignin structure in the desired manner.
- Subjects :
- Signal peptide
Cinnamyl-alcohol dehydrogenase
Arabidopsis
Dehydrogenase
Plant Science
Biology
Lignin
Cell wall
chemistry.chemical_compound
Phenols
Cell Wall
Arabidopsis thaliana
chemistry.chemical_classification
fungi
food and beverages
biology.organism_classification
Sphingomonadaceae
Enzyme
Biochemistry
chemistry
Oxidoreductases
Agronomy and Crop Science
Dimerization
Biotechnology
Subjects
Details
- ISSN :
- 14677652
- Volume :
- 13
- Issue :
- 6
- Database :
- OpenAIRE
- Journal :
- Plant biotechnology journal
- Accession number :
- edsair.doi.dedup.....3777527570845403843fe15c4b656bf7