Article

A Laccase Associated with Lignification in Loblolly Pine Xylem

Science (Impact Factor: 33.61). 05/1993; 260(5108):672-4. DOI: 10.1126/science.260.5108.672
Source: PubMed

ABSTRACT

Peroxidase has been thought to be the only enzyme that oxidizes monolignol precursors to initiate lignin formation in plants. A laccase was purified from cell walls of differentiating xylem of loblolly pine and shown to coincide in time and place with lignin formation and to oxidize monolignols to dehydrogenation products in vitro. These results suggest that laccase participates in lignin biosynthesis and therefore could be an important target for genetic engineering to modify wood properties or to improve the digestibility of forage crops.

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Available from: Ronald Sederoff, Apr 01, 2014
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    • "Chronological Development of Laccase Applications to Fiberboard Fabrication Reference Novelty Application Yoshida (1883) Discovered laccase Discovered for the first time in latex from the Japanese lacquer tree (Rhus vernicifera) Yamaguchi et al. (1992) phenol dehydrogenative polymerization Achieved bonding among woody-fibers by polymerisation Bao et al. (1993) "
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    ABSTRACT: In the last two decades, laccases have received much attention from researchers because of their specific ability to oxidize lignin. This function of laccase is very useful for applications in several biotechnological processes, including delignification in the pulp and paper industry and the detoxification of industrial effluents from the textile and petrochemical industries. This review focuses on laccase-mediated fiberboard synthesis. Growing concerns regarding the emission of formaldehyde from wood composites has prompted industrialists to consider the fabrication of green composites. Laccase-mediated fiber treatments oxidize the lignin component without affecting the cellulose structure. As a result, free radicals are generated on the fiber surface, and these can act as potential reactive sites for further cross-linking reactions in board manufacturing. Binderless fiberboards prepared using such methods can be considered as green composites because the manufacturing process involves no additional resin.
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    • "It will be interesting to see whether the assembly of lignin polymerization complex by CASPs or CASP-like proteins observed in the formation of Casparian strip is a general feature that applies to other types of lignifying cells. Similar to peroxidase, laccase (p-diphenol:dioxygen oxidoreductase , EC 1.10.3.2) also oxidizes monolignols in vitro (Bao et al., 1993; Freudenberg, 1959; Richardson et al., 1997; Sterjiades et al., 1992; Takahama, 1995), and laccase-like activities have been detected in the lignifying cell walls of differentiating xylem (Bao et al., 1993; Driouich et al., 1992; Liu et al., 1994; Richardson et al., 2000). Laccases are coppercontaining extracellular glycoproteins that require O 2 as secondary substrate to oxidize various phenolic, inorganic, and/or aromatic amine substrates (Reinhammar and Malmstroem, 1981). "
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    • "It was first suggested over 20 years ago that laccases are involved in oxidative lignin polymerization in plant species (Sterjiades et al., 1992; Bao et al., 1993). However, early studies mostly addressed oxidation of lignin precursors in vitro. "
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