Disruption of<i>p</i>-coumaroyl-CoA:monolignol transferases in rice drastically alters lignin composition
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- Lydia Pui Ying Lam
- Research Institute for Sustainable Humanosphere, Kyoto University , Uji, Kyoto 611-0011 , Japan
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- Yuki Tobimatsu
- Research Institute for Sustainable Humanosphere, Kyoto University , Uji, Kyoto 611-0011 , Japan
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- Shiro Suzuki
- Research Institute for Sustainable Humanosphere, Kyoto University , Uji, Kyoto 611-0011 , Japan
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- Takuto Tanaka
- Research Institute for Sustainable Humanosphere, Kyoto University , Uji, Kyoto 611-0011 , Japan
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- Senri Yamamoto
- Research Institute for Sustainable Humanosphere, Kyoto University , Uji, Kyoto 611-0011 , Japan
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- Yuri Takeda-Kimura
- Research Institute for Sustainable Humanosphere, Kyoto University , Uji, Kyoto 611-0011 , Japan
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- Yuriko Osakabe
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama , Kanagawa 226-8502 Japan
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- Keishi Osakabe
- Faculty of Bioscience and Bioindustry, Tokushima University , Tokushima, Tokushima 770-8503 Japan
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- John Ralph
- Department of Biochemistry, and the U.S. Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin , Madison, WI 53726 , USA
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- Laura E Bartley
- Research Institute for Sustainable Humanosphere, Kyoto University , Uji, Kyoto 611-0011 , Japan
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- Toshiaki Umezawa
- Research Institute for Sustainable Humanosphere, Kyoto University , Uji, Kyoto 611-0011 , Japan
説明
<jats:title>Abstract</jats:title><jats:p>Grasses are abundant feedstocks that can supply lignocellulosic biomass for production of cell-wall-derived chemicals. In grass cell walls, lignin is acylated with p-coumarate. These p-coumarate decorations arise from the incorporation of monolignol p-coumarate conjugates during lignification. A previous biochemical study identified a rice (Oryza sativa) BAHD acyltransferase (AT) with p-coumaroyl-CoA:monolignol transferase (PMT) activity in vitro. In this study, we determined that that enzyme, which we name OsPMT1 (also known as OsAT4), and the closely related OsPMT2 (OsAT3) harbor similar catalytic activity toward monolignols. We generated rice mutants deficient in either or both OsPMT1 and OsPMT2 by CRISPR/Cas9-mediated mutagenesis and subjected the mutants’ cell walls to analysis using chemical and nuclear magnetic resonance methods. Our results demonstrated that OsPMT1 and OsPMT2 both function in lignin p-coumaroylation in the major vegetative tissues of rice. Notably, lignin-bound p-coumarate units were undetectable in the ospmt1 ospmt2-2 double-knockout mutant. Further, in-depth structural analysis of purified lignins from the ospmt1 ospmt2-2 mutant compared with control lignins from wild-type rice revealed stark changes in polymer structures, including alterations in syringyl/guaiacyl aromatic unit ratios and inter-monomeric linkage patterns, and increased molecular weights. Our results provide insights into lignin polymerization in grasses that will be useful for the optimization of bioengineering approaches for the effective use of biomass in biorefineries.</jats:p>
収録刊行物
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- Plant Physiology
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Plant Physiology 194 (2), 832-848, 2023-10-13
Oxford University Press (OUP)
