Introduction of chemically labile substructures into Arabidopsis lignin through the use of LigD, the Cα‐dehydrogenase from Sphingobium sp. strain SYK‐6. Issue 6 (8th January 2015)

• Record Type: Journal Article
• Authors: Tsuji, Yukiko; Vanholme, Ruben; Tobimatsu, Yuki; Ishikawa, Yasuyuki; Foster, Clifton E.; Kamimura, Naofumi; Hishiyama, Shojiro; Hashimoto, Saki; Shino, Amiu; Hara, Hirofumi; Sato‐Izawa, Kanna; Oyarce, Paula; Goeminne, Geert; Morreel, Kris; Kikuchi, Jun; Takano, Toshiyuki; Fukuda, Masao; Katayama, Yoshihiro; Boerjan, Wout; Ralph, John; Masai, Eiji; Kajita, Shinya
• Is Part Of: Plant biotechnology journal. Volume 13:Issue 6(2015:Aug.)
• Page Start: 821
• Page End: 832
• Publication Date: 2015-01-08
• Subjects: Plant biotechnology -- Periodicals; Plant genetic engineering -- Periodicals; 630.272
• DOI: 10.1111/pbi.12316
• Languages: English
• ISSNs: 1467-7644

Abstract

<abstract abstract-type="main" id="pbi12316-abs-0001"> <title>Summary</title> <p>Bacteria‐derived enzymes that can modify specific lignin substructures are potential targets to engineer plants for better biomass processability. The Gram‐negative bacterium <italic>Sphingobium</italic> 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 <italic>ligD</italic> gene in <italic>Arabidopsis thaliana</italic>. The <italic>ligD </italic>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.</p> </abstract>