Lignin biosynthesis perturbations affect secondary cell wall composition and saccharification yield in Arabidopsis thaliana

The secondary wall is the main part of wood and is composed of cellulose, xylan, lignin, and small amounts of structural proteins and enzymes. Lignin molecules can interact directly or indirectly with cellulose, xylan and other polysaccharide molecules in the cell wall, increasing the mechanical strength and hydrophobicity of plant cells and tissues and facilitating the long-distance transportation of water in plants. MYBs (v-myb avian myeloblastosis viral oncogene homolog) belong to one of the largest superfamilies of transcription factors, the members of which regulate secondary cell-wall formation by promoting/inhibiting the biosynthesis of lignin, cellulose, and xylan. Among them, MYB46 and MYB83, which comprise the second layer of the main switch of secondary cell-wall biosynthesis, coordinate upstream and downstream secondary wall synthesis-related transcription factors. In addition, MYB transcription factors other than MYB46/83, as well as noncoding RNAs, hormones, and other factors, interact with one another to regulate the biosynthesis of the secondary wall. Here, we discuss the biosynthesis of secondary wall, classification and functions of MYB transcription factors and their regulation of lignin polymerization and secondary cell-wall formation during wood formation.

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Distinct and overlapping functions of Miscanthus sinensis MYB transcription factors SCM1 and MYB103 in lignin biosynthesis

10.1101/629709 ◽

2019 ◽

Author(s):

Philippe Golfier ◽

Faride Unda ◽

Emily K. Murphy ◽

Jianbo Xie ◽

Feng He ◽

...

Keyword(s):

Cell Wall ◽

Transcriptional Regulation ◽

Secondary Cell Wall ◽

Lignin Content ◽

Lignin Biosynthesis ◽

Miscanthus Sinensis ◽

Cell Wall Formation ◽

Transcriptional Responses ◽

Secondary Cell Wall Formation ◽

Wall Formation

AbstractCell wall recalcitrance is a major constraint for the exploitation of lignocellulosic biomass as renewable resource for energy and bio-based products. Transcriptional regulators of the lignin biosynthetic pathway represent promising targets for tailoring lignin content and composition in plant secondary cell walls. A wealth of research in model organisms has revealed that transcriptional regulation of secondary cell wall formation is orchestrated by a hierarchical transcription factor (TF) network with NAC TFs as master regulators and MYB factors in the lower tier regulators. However, knowledge about the transcriptional regulation of lignin biosynthesis in lignocellulosic feedstocks, such as Miscanthus, is limited. Here, we characterized two Miscanthus MYB TFs, MsSCM1 and MsMYB103, and compared their transcriptional impact with that of the master regulator MsSND1. In Miscanthus leaves MsSCM1 and MsMYB103 are expressed at growth stages associated with lignification. Ectopic expression of MsSCM1 and MsMYB103 in tobacco leaves was sufficient to trigger secondary cell wall deposition with distinct sugar and lignin composition. Moreover, RNA-seq analysis revealed that the transcriptional responses to MsSCM1 and MsMYB103 overexpression showed extensive overlap with the response to MsSND1, but were distinct from each other, underscoring the inherent complexity of secondary cell wall formation. Together, MsSCM1 and MsMYB103 represent interesting targets for manipulations of lignin content and composition in Miscanthus towards tailored biomass.

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Reduced photosynthesis in Arabidopsis thaliana atpme17.2 and atpae11.1 mutants is associated to altered cell wall composition

Physiologia Plantarum ◽

10.1111/ppl.13186 ◽

2020 ◽

Cited By ~ 1

Author(s):

Margalida Roig‐Oliver ◽

Catherine Rayon ◽

Romain Roulard ◽

François Fournet ◽

Josefina Bota ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Cell Wall ◽

Cell Wall Composition ◽

Altered Cell

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Secondary cell wall composition and candidate gene expression in developing willow (Salix purpurea) stems

Planta ◽

10.1007/s00425-014-2034-1 ◽

2014 ◽

Vol 239 (5) ◽

pp. 1041-1053 ◽

Cited By ~ 6

Author(s):

Yongfang Wan ◽

Cristina Gritsch ◽

Theodora Tryfona ◽

Mike J. Ray ◽

Ambrose Andongabo ◽

...

Keyword(s):

Gene Expression ◽

Cell Wall ◽

Candidate Gene ◽

Secondary Cell Wall ◽

Cell Wall Composition ◽

Salix Purpurea

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PdWND3A, a wood-associated NAC domain-containing protein, affects lignin biosynthesis and composition in Populus

BMC Plant Biology ◽

10.1186/s12870-019-2111-5 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 2

Author(s):

Yongil Yang ◽

Chang Geun Yoo ◽

William Rottmann ◽

Kimberly A. Winkeler ◽

Cassandra M. Collins ◽

...

Keyword(s):

Cell Wall ◽

Transcription Factor ◽

Transgenic Plants ◽

Secondary Cell Wall ◽

Lignin Biosynthesis ◽

Cell Wall Biosynthesis ◽

Wild Type ◽

Nac Domain ◽

Sugar Release ◽

Secondary Cell Wall Biosynthesis

Abstract Background Plant secondary cell wall is a renewable feedstock for biofuels and biomaterials production. Arabidopsis VASCULAR-RELATED NAC DOMAIN (VND) has been demonstrated to be a key transcription factor regulating secondary cell wall biosynthesis. However, less is known about its role in the woody species. Results Here we report the functional characterization of Populus deltoides WOOD-ASSOCIATED NAC DOMAIN protein 3 (PdWND3A), a sequence homolog of Arabidopsis VND4 and VND5 that are members of transcription factor networks regulating secondary cell wall biosynthesis. PdWND3A was expressed at higher level in the xylem than in other tissues. The stem tissues of transgenic P. deltoides overexpressing PdWND3A (OXPdWND3A) contained more vessel cells than that of wild-type plants. Furthermore, lignin content and lignin monomer syringyl and guaiacyl (S/G) ratio were higher in OXPdWND3A transgenic plants than in wild-type plants. Consistent with these observations, the expression of FERULATE 5-HYDROXYLASE1 (F5H1), encoding an enzyme involved in the biosynthesis of sinapyl alcohol (S unit monolignol), was elevated in OXPdWND3A transgenic plants. Saccharification analysis indicated that the rate of sugar release was reduced in the transgenic plants. In addition, OXPdWND3A transgenic plants produced lower amounts of biomass than wild-type plants. Conclusions PdWND3A affects lignin biosynthesis and composition and negatively impacts sugar release and biomass production.

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Overexpression ofSbMyb60impacts phenylpropanoid biosynthesis and alters secondary cell wall composition inSorghum bicolor

The Plant Journal ◽

10.1111/tpj.13112 ◽

2016 ◽

Vol 85 (3) ◽

pp. 378-395 ◽

Cited By ~ 42

Author(s):

Erin D. Scully ◽

Tammy Gries ◽

Gautam Sarath ◽

Nathan A. Palmer ◽

Lisa Baird ◽

...

Keyword(s):

Cell Wall ◽

Secondary Cell Wall ◽

Cell Wall Composition ◽

Phenylpropanoid Biosynthesis

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PmMYB4, a Transcriptional Activator from Pinus massoniana, Regulates Secondary Cell Wall Formation and Lignin Biosynthesis

Forests ◽

10.3390/f12121618 ◽

2021 ◽

Vol 12 (12) ◽

pp. 1618

Author(s):

Sheng Yao ◽

Peizhen Chen ◽

Ye Yu ◽

Mengyang Zhang ◽

Dengbao Wang ◽

...

Keyword(s):

Cell Wall ◽

Secondary Cell Wall ◽

Paper Industry ◽

Lignin Biosynthesis ◽

Pinus Massoniana ◽

Wood Formation ◽

Genetically Engineered ◽

Cellulose Synthesis ◽

Masson Pine ◽

Reading Frame

Wood formation originates in the biosynthesis of lignin and further leads to secondary cell wall (SCW) biosynthesis in woody plants. Masson pine (Pinus massoniana Lamb) is an economically important industrial timber tree, and its wood yield affects the stable development of the paper industry. However, the regulatory mechanisms of SCW formation in Masson pine are still unclear. In this study, we characterized PmMYB4, which is a Pinus massoniana MYB gene involved in SCW biosynthesis. The open reading frame (ORF) of PmMYB4 was 1473 bp, which encoded a 490 aa protein and contained two distinctive R2 and R3 MYB domains. It was shown to be a transcription factor, with the highest expression in semi-lignified stems. We overexpressed PmMYB4 in tobacco. The results indicated that PmMYB4 overexpression increased lignin deposition, SCW thickness, and the expression of genes involved in SCW formation. Further analysis indicated that PmMYB4 bound to AC-box motifs and might directly activate the promoters of genes (PmPAL and PmCCoAOMT) involved in SCW biosynthesis. In addition, PmMYB4-OE(over expression) transgenic lines had higher lignin and cellulose contents and gene expression than control plants, indicating that PmMYB4 regulates SCW mainly by targeting lignin biosynthetic genes. In summary, this study illustrated the MYB-induced SCW mechanism in Masson pine and will facilitate enhanced lignin and cellulose synthesis in genetically engineered trees.

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Abscisic acid regulates secondary cell-wall formation and lignin deposition in Arabidopsis thaliana through phosphorylation of NST1

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2010911118 ◽

2021 ◽

Vol 118 (5) ◽

pp. e2010911118

Author(s):

Chang Liu ◽

Hasi Yu ◽

Xiaolan Rao ◽

Laigeng Li ◽

Richard A. Dixon

Keyword(s):

Arabidopsis Thaliana ◽

Cell Wall ◽

Abscisic Acid ◽

Transcriptional Activation ◽

Secondary Cell Wall ◽

Wall Thickening ◽

Gene Promoters ◽

Loss Of Function ◽

Tolerance Strategy ◽

Pathway Gene

Plant secondary cell-wall (SCW) deposition and lignification are affected by both seasonal factors and abiotic stress, and these responses may involve the hormone abscisic acid (ABA). However, the mechanisms involved are not clear. Here we show that mutations that limit ABA synthesis or signaling reduce the extent of SCW thickness and lignification in Arabidopsis thaliana through the core ABA-signaling pathway involving SnRK2 kinases. SnRK2.2. 3 and 6 physically interact with the SCW regulator NAC SECONDARY WALL THICKENING PROMOTING FACTOR 1 (NST1), a NAC family transcription factor that orchestrates the transcriptional activation of a suite of downstream SCW biosynthesis genes, some of which are involved in the biosynthesis of cellulose and lignin. This interaction leads to phosphorylation of NST1 at Ser316, a residue that is highly conserved among NST1 proteins from dicots, but not monocots, and is required for transcriptional activation of downstream SCW-related gene promoters. Loss of function of NST1 in the snd1 mutant background results in lack of SCWs in the interfascicular fiber region of the stem, and the Ser316Ala mutant of NST1 fails to complement this phenotype and ABA-induced lignin pathway gene expression. The discovery of NST1 as a key substrate for phosphorylation by SnRK2 suggests that the ABA-mediated core-signaling cascade provided land plants with a hormone-modulated, competitive desiccation-tolerance strategy allowing them to differentiate water-conducting and supporting tissues built of cells with thicker cell walls.

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The BpMYB4 Transcription Factor From Betula platyphylla Contributes Toward Abiotic Stress Resistance and Secondary Cell Wall Biosynthesis

Frontiers in Plant Science ◽

10.3389/fpls.2020.606062 ◽

2021 ◽

Vol 11 ◽

Author(s):

Ying Yu ◽

Huizi Liu ◽

Nan Zhang ◽

Caiqiu Gao ◽

Liwang Qi ◽

...

Keyword(s):

Cell Wall ◽

Transcription Factor ◽

Abiotic Stress ◽

Transgenic Plants ◽

Stress Resistance ◽

Secondary Cell Wall ◽

Lignin Content ◽

Lignin Biosynthesis ◽

Betula Platyphylla ◽

Wild Type

The MYB (v-myb avian myeloblastosis viral oncogene homolog) family is one of the largest transcription factor families in plants, and is widely involved in the regulation of plant metabolism. In this study, we show that a MYB4 transcription factor, BpMYB4, identified from birch (Betula platyphylla Suk.) and homologous to EgMYB1 from Eucalyptus robusta Smith and ZmMYB31 from Zea mays L. is involved in secondary cell wall synthesis. The expression level of BpMYB4 was higher in flowers relative to other tissues, and was induced by artificial bending and gravitational stimuli in developing xylem tissues. The expression of this gene was not enriched in the developing xylem during the active season, and showed higher transcript levels in xylem tissues around sprouting and near the dormant period. BpMYB4 also was induced express by abiotic stress. Functional analysis indicated that expression of BpMYB4 in transgenic Arabidopsis (Arabidopsis thaliana) plants could promote the growth of stems, and result in increased number of inflorescence stems and shoots. Anatomical observation of stem sections showed lower lignin deposition, and a chemical contents test also demonstrated increased cellulose and decreased lignin content in the transgenic plants. In addition, treatment with 100 mM NaCl and 200 mM mannitol resulted in the germination rate of the over-expressed lines being higher than that of the wild-type seeds. The proline content in transgenic plants was higher than that in WT, but MDA content was lower than that in WT. Further investigation in birch using transient transformation techniques indicated that overexpression of BpMYB4 could scavenge hydrogen peroxide and O2.– and reduce cell damage, compared with the wild-type plants. Therefore, we believe that BpMYB4 promotes stem development and cellulose biosynthesis as an inhibitor of lignin biosynthesis, and has a function in abiotic stress resistance.

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