scholarly journals Patatin-Related Phospholipase AtpPLAIIIα Affects Lignification of Xylem in Arabidopsis and Hybrid Poplars

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 451 ◽  
Author(s):  
Jin Hoon Jang ◽  
Ok Ran Lee
Keyword(s):  
Cell Walls ◽  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Biofuel Production ◽  
Amide Bonds ◽  
Hybrid Poplars ◽  
Plant Lipids ◽  
Lipid Acyl Hydrolase ◽  
Specific Regulation

Lipid acyl hydrolase are a diverse group of enzymes that hydrolyze the ester or amide bonds of fatty acid in plant lipids. Patatin-related phospholipase AIIIs (pPLAIIIs) are one of major lipid acyl hydrolases that are less closely related to potato tuber patatins and are plant-specific. Recently, overexpression of ginseng-derived PgpPLAIIIβ was reported to be involved in the reduced level of lignin content in Arabidopsis and the mature xylem layer of poplar. The presence of lignin-polysaccharides renders cell walls recalcitrant for pulping and biofuel production. The tissue-specific regulation of lignin biosynthesis, without altering all xylem in plants, can be utilized usefully by keeping mechanical strength and resistance to various environmental stimuli. To identify another pPLAIII homolog from Arabidopsis, constitutively overexpressed AtpPLAIIIα was characterized for xylem lignification in two well-studied model plants, Arabidopsis and poplar. The characterization of gene function in annual and perennial plants with respect to lignin biosynthesis revealed the functional redundancy of less lignification via downregulation of lignin biosynthesis-related genes.

scholarly journals CRISPR-Knockout of CSE Gene Improves Saccharification Efficiency by Reducing Lignin Content in Hybrid Poplar

2021 ◽  
Vol 22 (18) ◽  
pp. 9750
Author(s):  
Hyun-A Jang ◽  
Eun-Kyung Bae ◽  
Min-Ha Kim ◽  
Su-Jin Park ◽  
Na-Young Choi ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Lignin Content ◽  
Hybrid Poplar ◽  
Lignin Biosynthesis ◽  
Biofuel Production ◽  
Guide Rnas ◽  
Hybrid Poplars ◽  
Four Seasons ◽  
Promising Target ◽  
Saccharification Efficiency

Caffeoyl shikimate esterase (CSE) has been shown to play an important role in lignin biosynthesis in plants and is, therefore, a promising target for generating improved lignocellulosic biomass crops for sustainable biofuel production. Populus spp. has two CSE genes (CSE1 and CSE2) and, thus, the hybrid poplar (Populus alba × P. glandulosa) investigated in this study has four CSE genes. Here, we present transgenic hybrid poplars with knockouts of each CSE gene achieved by CRISPR/Cas9. To knockout the CSE genes of the hybrid poplar, we designed three single guide RNAs (sg1–sg3), and produced three different transgenic poplars with either CSE1 (CSE1-sg2), CSE2 (CSE2-sg3), or both genes (CSE1/2-sg1) mutated. CSE1-sg2 and CSE2-sg3 poplars showed up to 29.1% reduction in lignin deposition with irregularly shaped xylem vessels. However, CSE1-sg2 and CSE2-sg3 poplars were morphologically indistinguishable from WT and showed no significant differences in growth in a long-term living modified organism (LMO) field-test covering four seasons. Gene expression analysis revealed that many lignin biosynthetic genes were downregulated in CSE1-sg2 and CSE2-sg3 poplars. Indeed, the CSE1-sg2 and CSE2-sg3 poplars had up to 25% higher saccharification efficiency than the WT control. Our results demonstrate that precise editing of CSE by CRISPR/Cas9 technology can improve lignocellulosic biomass without a growth penalty.

scholarly journals The in vivo impact of MsLAC1, a Miscanthus laccase isoform, on lignification and lignin composition contrasts with its in vitro substrate preference

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Feng He ◽  
Katja Machemer-Noonan ◽  
Philippe Golfier ◽  
Faride Unda ◽  
Johanna Dechert ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factors ◽  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Lignin Composition ◽  
Xylem Fibers ◽  
Breeding Target

Abstract Background Understanding lignin biosynthesis and composition is of central importance for sustainable bioenergy and biomaterials production. Species of the genus Miscanthus have emerged as promising bioenergy crop due to their rapid growth and modest nutrient requirements. However, lignin polymerization in Miscanthus is poorly understood. It was previously shown that plant laccases are phenol oxidases that have multiple functions in plant, one of which is the polymerization of monolignols. Herein, we link a newly discovered Miscanthus laccase, MsLAC1, to cell wall lignification. Characterization of recombinant MsLAC1 and Arabidopsis transgenic plants expressing MsLAC1 were carried out to understand the function of MsLAC1 both in vitro and in vivo. Results Using a comprehensive suite of molecular, biochemical and histochemical analyses, we show that MsLAC1 localizes to cell walls and identify Miscanthus transcription factors capable of regulating MsLAC1 expression. In addition, MsLAC1 complements the Arabidopsis lac4–2 lac17 mutant and recombinant MsLAC1 is able to oxidize monolignol in vitro. Transgenic Arabidopsis plants over-expressing MsLAC1 show higher G-lignin content, although recombinant MsLAC1 seemed to prefer sinapyl alcohol as substrate. Conclusions In summary, our results suggest that MsLAC1 is regulated by secondary cell wall MYB transcription factors and is involved in lignification of xylem fibers. This report identifies MsLAC1 as a promising breeding target in Miscanthus for biofuel and biomaterial applications.

scholarly journals Autolysis of isolated cell walls of Bacillus licheniformis N.C.T.C. 6346 and Bacillus subtilis Marburg strain 168. Separation of the products and characterization of the mucopeptide fragments

1970 ◽  
Vol 119 (5) ◽  
pp. 849-860 ◽  
Author(s):  
R. C. Hughes
Keyword(s):  
Bacillus Subtilis ◽  
Bacillus Licheniformis ◽  
Cell Walls ◽  
Deae Cellulose ◽  
Casein Hydrolysate ◽  
Diaminopimelic Acid ◽  
Average Chain Length ◽  
Amide Bonds ◽  
Chain Lengths

1. Cell walls were isolated from Bacillus licheniformis N.C.T.C. 6346 and Bacillus subtilis Marburg strain 168 trp grown on casein hydrolysate into exponential phase. Autolysis was carried out and the soluble products, separated by chromatography on DEAE-cellulose, from the two wall preparations are broadly similar in composition and are in agreement with autolysis proceeding with hydrolysis of amide bonds between l-alanine and N-acetylmuramic acid residues in the mucopeptide components. 2. Peptides originating from the mucopeptide components were isolated and shown to be a monomer peptide, l-alanyl-d-glutamyl-meso-diaminopimelic acid and a dimer peptide containing two monomer peptides linked through a residue of d-alanine. Approximately one amide group is present for each equivalent tripeptide unit and is probably substituted on diaminopimelic acid residues. 3. Oligosaccharides originating from the mucopeptide components were isolated and after hydrolysis contained almost equimolar amounts of glucosamine and muramic acid and only very small amounts of amino acids. The number-average chain length, estimated by the release of non-reducing end groups of N-acetylglucosamine with exo-β-N-acetylglucosaminidase, is approximately ten hexosamine residues for oligosaccharides isolated from either organism. The oligosaccharides are polydisperse. 4. N-Acetylglucosamine residues are the only reducing terminals detectable in the oligosaccharides isolated from B. subtilis or B. licheniformis cell-wall autolysates. The number-average chain lengths of the oligosaccharides were determined by estimation of the content of these residues and are higher than those found by enzymic assay. Possible reasons for the discrepancy are discussed.

Ultrastructural characterization of wood from Tertiary fossil forests in the Canadian Arctic

1991 ◽  
Vol 69 (3) ◽  
pp. 560-568 ◽  
Author(s):  
Robert A. Blanchette ◽  
Kory R. Cease ◽  
André R. Abad ◽  
Todd A. Burnes ◽  
John R. Obst
Keyword(s):  
Cell Walls ◽  
Lignin Content ◽  
Cellulose Degradation ◽  
Amorphous Material ◽  
High Arctic ◽  
Fossil Wood ◽  
The Arctic ◽  
Ultrastructural Characterization ◽  
Hemicellulose Degradation

Micromorphological and ultrastructural characterization of fossil gymnosperm wood from Comwallis Island, Axel Heiberg Island, and Ellesmere Island in the Canadian High Arctic showed the changes that have occurred in cell walls of wood during 20–60 million years of burial. No evidence of permineralization was observed. Wood with rounded cells, thick secondary walls, and intercellular spaces was common in all samples. Secondary walls were eroded and swollen. A transition from an organized secondary wall, with altered but visible microfibrillar structure, to an electron-dense, amorphous material was evident in cell walls. The amorphous material appeared to form primarily in the secondary walls near cell lumina and along cracks that extended into the walls. The middle lamellae were often expanded in size and had convoluted shapes. Hemicellulose degradation appeared to precede cellulose degradation. Samples exhibiting cell walls with increased amorphous material had the greatest lignin and lowest cellulose concentrations. Hemicellulose concentration was extremely low in all Eocene and Paleocene samples. The lignin content of Miocene wood was 47.9%, whereas the Eocene and Paleocene samples ranged from 66 to 84%. Tracheids from extensively degraded samples were distorted and collapsed, and in some cases the cells appeared compressed together. Although the residual amorphous middle lamellae and secondary walls were fused together, the outlines of original cells were visible. Chemical analyses and ultrastructural data indicated that a nonbiological degradation was responsible for the deterioration of the arctic fossil wood samples. Key words: wood deterioration, lignin, hemicelluloses, cellulose, wood ultrastructure, coal formation, fossil wood.

scholarly journals Low Lignin Mutants and Reduction of Lignin Content in Grasses for Increased Utilisation of Lignocellulose

Agronomy ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 256 ◽  
Author(s):  
Cecilie S. L. Christensen ◽  
Søren K. Rasmussen
Keyword(s):  
Animal Feed ◽  
Lignin Content ◽  
Lignin Biosynthesis ◽  
Biofuel Production ◽  
Phenotypic Traits ◽  
Monolignol Biosynthesis ◽  
Genes Encoding ◽  
Regulated Gene Expression ◽  
Mutant Lines ◽  
The Impact

Biomass rich in lignocellulose from grasses is a major source for biofuel production and animal feed. However, the presence of lignin in cell walls limits its efficient utilisation such as in its bioconversion to biofuel. Reduction of the lignin content or alteration of its structure in crop plants have been pursued, either by regulating genes encoding enzymes in the lignin biosynthetic pathway using biotechnological techniques or by breeding naturally-occurring low lignin mutant lines. The aim of this review is to provide a summary of these studies, focusing on lignin (monolignol) biosynthesis and composition in grasses and, where possible, the impact on recalcitrance to bioconversion. An overview of transgenic crops of the grass family with regulated gene expression in lignin biosynthesis is presented, including the effect on lignin content and changes in the ratio of p-hydroxyphenyl (H), guaiacyl (G) and syringyl (S) units. Furthermore, a survey is provided of low-lignin mutants in grasses, including cereals in particular, summarising their origin and phenotypic traits together with genetics and the molecular function of the various genes identified.

scholarly journals Compositional analysis and characterization of lignocellulosic biomass from selected agricultural wastes

2020 ◽  
Vol 8 (1) ◽  
pp. 48-56
Author(s):  
Adewale Elijah Fadeyi ◽  
Saheed Olatunbosun Akiode ◽  
Stella A Emmanuel ◽  
Olajide Ebenezer Falayi
Keyword(s):  
Lignocellulosic Biomass ◽  
Lignin Content ◽  
Broad Band ◽  
Gravimetric Method ◽  
Compositional Analysis ◽  
Agricultural Wastes ◽  
Biofuel Production ◽  
Biomass Composition ◽  
Oh Groups

Agricultural wastes have been identified as a potential lignocellulosic biomass for bioethanol production. An accurate biomass characterization is needed to evaluate the new potential lignocelluloses biosource for biofuel production. This study evaluates the compositional analysis and characterization of three agricultural wastes (melon husk, moringa pod and mango endocarp). The samples were collected locally in Sheda Village, FCT, Abuja, Nigeria. The lignocellulose biomass composition of the samples was determined by using a proven economically viable gravimetric method and the samples were further characterized using the FTIR. The results showed that a significant amount of hemicelluloses content was found, from 19.38% to 27.74% and the highest amount was present in melon musk. The amount of cellulose ranging from 22.49% to 45.84% was found where the highest amount was found in mango endocarp. Lignin content was in the range of 22.62% to 29.87% and melon husk was shown to have the highest amount. The FTIR spectroscopic analysis showed a broad band at 3422.99 cm-1, 3422.66 cm-1, 3422.85 cm-1 (for mango endocarp, melon husk and moringa pod respectively) representing bonded –OH groups. The peak around 1637 cm-1 corresponds to C=C stretching of conjugated carboxylic acids. The aliphatic chains, -CH2- and –CH3, which form the basic structure of cellulose material, were seen at 1205.72, 1204.50 and 1206.24 cm-1. The signals at 1056.15, 1035.80 and 1055.86 cm-1 correspond to C-O-R (alcohols or esters) vibration. The results show that the samples contain significant quantity of lignocellulosic biomass. Thus, the agricultural wastes could be of valuable use in biofuel production.

Forages for feedstocks of biorefineries in temperate environments: review of lignin research in bioenergy crops and some insight into Miscanthus studies

2014 ◽  
Vol 65 (11) ◽  
pp. 1199 ◽  
Author(s):  
Maria S. Dwiyanti ◽  
J. Ryan Stewart ◽  
Toshihiko Yamada
Keyword(s):  
Panicum Virgatum ◽  
Target Genes ◽  
Lignin Content ◽  
Genetic Regulation ◽  
Warm Season ◽  
Lignin Biosynthesis ◽  
Biofuel Production ◽  
Bioenergy Crops ◽  
Cost Efficient ◽  
Insight Into

Rhizomatous and perennial warm-season C4 grasses such as Miscanthus spp. and switchgrass (Panicum virgatum) are potential bioenergy crops for temperate regions. However, lignin in Miscanthus and switchgrass inhibits the cellulose digestion process during bioethanol production. One of the targets for improvement of forages from feedstocks to bioenergy crops is to develop a cost-efficient biorefinery process through lignin content manipulation. Numerous reports have shown that RNAi suppression of lignin-biosynthesis pathway genes can increase biomass fermentable sugar yields for biofuel production. These studies have also reported that RNAi suppression of cell-wall lignin biosynthesis can decrease biomass yield and resistance to biotic stress in the transgenic plants. Transcriptome and metabolome approaches can be used to clarify the networks and pathways of lignin biosynthesis to facilitate the identification of appropriate target genes for transformation. However, whole-genome sequencing of the forage species, which provides much-needed genomic information, is limited. Germplasm of natural, low-lignin mutants also plays a role in identification of genetic regulation of lignin content and this would be useful breeding material. Molecular markers have been developed and utilised to accelerate identification of quantitative trait loci/genes for traits relating to the biorefinery process. All of these studies will serve as basic information for supporting genetic improvement through classical breeding or genetic transformation, and offer the opportunity to develop cultivars which have enhanced biomass and are cost-efficient for biorefinery process.

scholarly journals Characterization of a sweet basil acyltransferase involved in eugenol biosynthesis

2020 ◽  
Vol 71 (12) ◽  
pp. 3638-3652 ◽  
Author(s):  
Niha Dhar ◽  
Sreelatha Sarangapani ◽  
Vaishnavi Amarr Reddy ◽  
Nadimuthu Kumar ◽  
Deepa Panicker ◽  
...  
Keyword(s):  
Lignin Content ◽  
Glandular Trichomes ◽  
Lignin Biosynthesis ◽  
Coniferyl Alcohol ◽  
Sweet Basil ◽  
Transgenic Lines ◽  
Common Substrate ◽  
Total Lignin

Abstract Sweet basil (Ocimum basilicum) plants produce its characteristic phenylpropene-rich essential oil in specialized structures known as peltate glandular trichomes (PGTs). Eugenol and chavicol are the major phenylpropenes produced by sweet basil varieties whose synthetic pathways are not fully elucidated. Eugenol is derived from coniferyl acetate by a reaction catalysed by eugenol synthase. An acyltransferase is proposed to convert coniferyl alcohol to coniferyl acetate which is the first committed step towards eugenol synthesis. Here, we perform a comparative next-generation transcriptome sequencing of different tissues of sweet basil, namely PGT, leaf, leaf stripped of PGTs (leaf–PGT), and roots, to identify differentially expressed transcripts specific to PGT. From these data, we identified a PGT-enriched BAHD acyltransferase gene ObCAAT1 and functionally characterized it. In vitro coupled reaction of ObCAAT1 with eugenol synthase in the presence of coniferyl alcohol resulted in eugenol production. Analysis of ObCAAT1-RNAi transgenic lines showed decreased levels of eugenol and accumulation of coniferyl alcohol and its derivatives. Coniferyl alcohol acts as a common substrate for phenylpropene and lignin biosynthesis. No differences were found in total lignin content of PGTs and leaves of transgenic lines, indicating that phenylpropene biosynthesis is not coupled to lignification in sweet basil.

scholarly journals Identification and Characterization of the CCoAOMT Gene Family in Apple, Chinese White Pear, and Peach

2021 ◽  
pp. 1-12
Author(s):  
Leli Li ◽  
Shutian Tao ◽  
Huangwei Zhang ◽  
Weijian Huang ◽  
Jim M. Dunwell ◽  
...  
Keyword(s):  
Gene Family ◽  
Prunus Persica ◽  
Lignin Content ◽  
Expression Patterns ◽  
Lignin Biosynthesis ◽  
Pathogenic Fungi ◽  
Development Stage ◽  
Chinese White ◽  
Main Components

Lignin is one of the main components of plant cell walls, which provides mechanical support for plants and also contributes to resisting against plant pathogenic fungi. In the fruit industry, the lignin content can affect the quality of fruit. The biosynthesis of lignin involves a variety of enzymes, of which caffeoyl-CoA 3-O-methyltransferase (CCoAOMT) is a class of methyltransferases that plays an essential role in lignin biosynthesis. Studies have been conducted on the CCoAOMT gene family in several species, including arabidopsis (Arabidopsis thaliana), black poplar (Populus nigra), and cotton (Gossypium hirsutum). Still, there is relatively little research on this gene family in the Rosaceae. In this study, we used bioinformatics to identify and characterize the CCoAOMT gene family in apple (Malus domestica), chinese white pear (Pyrus bretschneideri), and peach (Prunus persica). In total, 35 CCoAOMT genes were identified in the three Rosaceae species: 8 from chinese white pear, 12 from apple, and 15 from peach. By using structure analysis and collinearity analysis, we found 12 conserved motifs and 12 pairs of CCoAOMT genes with collinearity. In the phylogenetic tree, the gene family was mainly divided into two groups. The genes had different expression patterns during the growth and development stage of fruit, a finding that is consistent with the pattern of lignin accumulation. This study will be beneficial for further study of CCoAOMT genes.

Characterization of machined polystyrene foam

1989 ◽  
Vol 47 ◽  
pp. 372-373
Author(s):  
C. W. Price ◽  
E. F. Lindsey ◽  
R. M. Franks ◽  
M. A. Lane
Keyword(s):  
Surface Finish ◽  
Cell Walls ◽  
Surface Structures ◽  
Efficient Technique ◽  
Low Density ◽  
Polystyrene Foam ◽  
Planar Surfaces ◽  
Machining Characteristics

Diamond-point turning is an efficient technique for machining low-density polystyrene foam, and the surface finish can be substantially improved by grinding. However, both diamond-point turning and grinding tend to tear and fracture cell walls and leave asperities formed by agglomerations of fragmented cell walls. Vibratoming is proving to be an excellent technique to form planar surfaces in polystyrene, and the machining characteristics of vibratoming and diamond-point turning are compared.Our work has demonstrated that proper evaluation of surface structures in low density polystyrene foam requires stereoscopic examinations; tilts of + and − 3 1/2 degrees were used for the stereo pairs. Coating does not seriously distort low-density polystyrene foam. Therefore, the specimens were gold-palladium coated and examined in a Hitachi S-800 FESEM at 5 kV.

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