Inactivation of LACCASE8 and LACCASE5 genes in Brachypodium distachyon leads to severe decrease in lignin content and high increase in saccharification yield without impacting plant integrity

Abstract Background Hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase (HCT) is a central enzyme of the so-called “esters” pathway to monolignols. As originally envisioned, HCT functions twice in this pathway, to form coumaroyl shikimate and then, in the “reverse” direction, to convert caffeoyl shikimate to caffeoyl CoA. The discovery of a caffeoyl shikimate esterase (CSE) that forms caffeic acid directly from caffeoyl shikimate calls into question the need for the reverse HCT reaction in lignin biosynthesis. Loss of function of HCT gives severe growth phenotypes in several dicot plants, but less so in some monocots, questioning whether this enzyme, and therefore the shikimate shunt, plays the same role in both monocots and dicots. The model grass Brachypodium distachyon has two HCT genes, but lacks a classical CSE gene. This study was therefore conducted to evaluate the utility of HCT as a target for lignin modification in a species with an “incomplete” shikimate shunt. Results The kinetic properties of recombinant B. distachyon HCTs were compared with those from Arabidopsis thaliana, Medicago truncatula, and Panicum virgatum (switchgrass) for both the forward and reverse reactions. Along with two M. truncatula HCTs, B. distachyon HCT2 had the least kinetically unfavorable reverse HCT reaction, and this enzyme is induced when HCT1 is down-regulated. Down regulation of B. distachyon HCT1, or co-down-regulation of HCT1 and HCT2, by RNA interference led to reduced lignin levels, with only modest changes in lignin composition and molecular weight. Conclusions Down-regulation of HCT1, or co-down-regulation of both HCT genes, in B. distachyon results in less extensive changes in lignin content/composition and cell wall structure than observed following HCT down-regulation in dicots, with little negative impact on biomass yield. Nevertheless, HCT down-regulation leads to significant improvements in biomass saccharification efficiency, making this gene a preferred target for biotechnological improvement of grasses for bioprocessing.

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The PMT-driven p-coumaroylation of poplar lignins impacts lignin structure and improves wood saccharification

10.1101/2021.02.16.431462 ◽

2021 ◽

Author(s):

Catherine Lapierre ◽

Richard Sibout ◽

Françoise Laurans ◽

Marie-Claude Lesage-Descauses ◽

Annabelle Déjardin ◽

...

Keyword(s):

Lignin Content ◽

Brachypodium Distachyon ◽

Industrial Processing ◽

Promising Strategy ◽

Transgenic Lines ◽

Naoh Solution ◽

In The Wild ◽

C3 Grasses ◽

Poplar Growth ◽

Stem Lignin

ABSTRACTTransgenic poplars (Populus tremula x Populus alba, clone INRA 717-1B4) were produced by introducing the Brachypodium distachyon Bradi2g36910 (BdPMT1) gene driven by the Arabidopsis (Arabidopsis thaliana) Cinnamate 4-Hydroxylase (AtC4H) promoter in the wild-type (WT) line and in a line overexpressing the Arabidopsis Ferulate 5-Hydroxylase (AtF5H). BdPMT1 encodes a transferase which catalyzes the acylation of monolignols by p-coumaric acid (CA). Several BdPMT1- OE/WT and BdPMT1-OE/AtF5H-OE transgenic lines were grown in the greenhouse and BdPMT1 expression in xylem was confirmed by RT-PCR. The analysis of the cell walls (CW) of poplar stems and of corresponding purified dioxan lignins (DL) revealed that the BdPMT1-OE lignins were as p-coumaroylated as the lignins of C3 grass straws. For some transformants, CA levels even reached about 11 mg/g CW and 66 mg/g DL, which by far exceeds those of Brachypodium or wheat samples. This unprecedentedly high p-coumaroylation of poplar lignins affected neither the poplar growth, nor the stem lignin content. By contrast, the transgenic lignins were structurally modified, with an increase of terminal units with free phenolic groups. Relative to controls, this increase argues for a reduced polymerization degree of BdPMT1-OE lignins and makes them more soluble in cold NaOH solution. The p-coumaroylation of poplar samples, up to the levels of C3 grasses, improved the saccharification yield of alkali-pretreated poplar CW. These results establish that the genetically-driven p-coumaroylation of lignins is a promising strategy to make wood lignins more susceptible to the alkaline treatments that can be used during the industrial processing of lignocellulosics.One-sentence summaryThe expression of a grass p-coumaroyl-CoA:monolignol transferase induces a high p-coumaroylation of poplar lignins and a better saccharification of alkali-pretreated poplar wood without growth penalty

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Effect of gamma radiation on growth and lignin content in Brachypodium distachyon

Journal of Crop Science and Biotechnology ◽

10.1007/s12892-013-0022-9 ◽

2013 ◽

Vol 16 (2) ◽

pp. 105-110 ◽

Cited By ~ 7

Author(s):

Man Bo Lee ◽

Dae Yeon Kim ◽

Woong Bae Jeon ◽

Min Jeong Hong ◽

Yong Jin Lee ◽

...

Keyword(s):

Gamma Radiation ◽

Lignin Content ◽

Brachypodium Distachyon

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Silicification of wood-cell walls

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100169870 ◽

1994 ◽

Vol 52 ◽

pp. 428-429

Author(s):

S. E. Keckler ◽

D. M. Dabbs ◽

N. Yao ◽

I. A. Aksay

Keyword(s):

Electron Microscopy ◽

Cell Wall ◽

Cell Walls ◽

Lignin Content ◽

Resin Composite ◽

Middle Lamella ◽

Cellulose Fibers ◽

Complex Structures ◽

Rich Region ◽

Inorganic Precursors

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).

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Phytochrome-mediated effects on extracellular peroxidase activity, lignin content and bending resistance in etiolated Vicia faba epicotyls

Physiologia Plantarum ◽

10.1034/j.1399-3054.1994.920403.x ◽

1994 ◽

Vol 92 (4) ◽

pp. 555-562 ◽

Cited By ~ 1

Author(s):

Jorge J. Casal ◽

R. Alejandra Mella ◽

Carlos L. Ballare ◽

Sara Maldonado

Keyword(s):

Vicia Faba ◽

Peroxidase Activity ◽

Lignin Content ◽

Extracellular Peroxidase ◽

Mediated Effects ◽

Bending Resistance

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Does the kappa number method accurately reflect lignin content in nonwood pulps?

TAPPI Journal ◽

10.32964/tj17.11.611 ◽

2018 ◽

Vol 17 (11) ◽

pp. 611-617

Author(s):

Sabrina Burkhardt

Keyword(s):

Lignin Content ◽

Paper Industry ◽

Pulp And Paper Industry ◽

Original Data ◽

Kappa Number ◽

Klason Lignin ◽

Organic Functional Groups ◽

Pulp Properties ◽

Wood Pulps ◽

Hexenuronic Acid

The traditional kappa number method was developed in 1960 as a way to more quickly determine the level of lignin remaining in a completed or in-progress pulp. A significantly faster approach than the Klason lignin procedure, the kappa number method is based on the reaction of a strong oxidizing agent (KMnO4) with lignin and small amounts of other organic functional groups present in the pulp, such as hexenuronic acid. While the usefulness of the kappa number for providing information about bleaching requirements and pulp properties has arguably transformed the pulp and paper industry, it has been mostly developed for kraft, sulfite, and soda wood pulps. Nonwood species have a different chemical makeup than hardwood or softwood sources. These chemical differ-ences can influence kappa and Klason measurements on the pulp and lead to wide ranges of error. Both original data from Sustainable Fiber Technologies’ sulfur and chlorine-free pulping process and kappa and Klason data from various nonwood pulp literature sources will be presented to challenge the assumption that the kappa number accurately represents lignin content in nonwood pulps.

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Faculty Opinions recommendation of Brachypodium distachyon. A new model system for functional genomics in grasses.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1002718.29955 ◽

2001 ◽

Author(s):

Vivian Irish

Keyword(s):

Functional Genomics ◽

Brachypodium Distachyon ◽

Model System ◽

New Model

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Faculty Opinions recommendation of Molecular and physiological analysis of growth-limiting drought stress in Brachypodium distachyon leaves.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717958108.793462412 ◽

2012 ◽

Author(s):

Alisdair Fernie ◽

Wagner Araujo

Keyword(s):

Drought Stress ◽

Brachypodium Distachyon ◽

Physiological Analysis

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Analysis of Sound Reduction and Strong Drag Composite Concrete Fibers Gedebok Banana Results Delignification with Sodium Hydroxide Solvent (Naoh)

Inovasi Pembangunan : Jurnal Kelitbangan ◽

10.35450/jip.v6i02.90 ◽

2018 ◽

Vol 6 (02) ◽

pp. 105-120

Author(s):

Muhammad Rouf Suprayogi ◽

Annisa Mufida ◽

Edwin Azwar

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Lignin Content ◽

Sound Intensity ◽

Cellulose Fiber ◽

Cellulose Content ◽

Cellulose Powder ◽

Drying Method ◽

Normal Concrete ◽

Sound Reduction

In composite science, desirable materials that are lighter but have the power and quality that can match or even exceed the material that has been there before. The purpose of this study was to investigate the effect of cellulose fiber addition from banana gedebok to tensile strength, compressive strength and damping of concrete composite sound. To achieve this objective, mixing of cellulose fibers with K-275 quality concrete mix with variation of 0% and 5% substitution in which the cellulose is varied in powder and wicker form. Delignification of lignin content from banana gedebok was done by soaking and drying method without any variation and yielding powder having cellulose content of 13,0388%, hemicellulose 18,2796% and lignin 0,6684%. This study produces concrete composites that have a tensile strength and a compressive strength lower than that of normal concrete. Normally reinforced concrete tensile strength value 94.5 kg / cm2, 71.4 kg / cm2 cellulose powder concrete and 90.3 kg / cm2 cellulose woven concrete. Normal concrete compressive strength value 334,22 kg / cm2, cellulose powder concrete 215,7 kg / cm2, and cellulose webbing concrete 157,98 kg / cm2. As for the power damping sound of cellulose webbing concrete has the highest damping power compared to other concrete with the absorbed sound intensity that is 52-68 dB

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