The R2R3 MYB transcription factor MYB189 negatively regulates secondary cell wall biosynthesis in Populus

2019 ◽  
Vol 39 (7) ◽  
pp. 1187-1200 ◽  
Author(s):  
Bo Jiao ◽  
Xin Zhao ◽  
Wanxiang Lu ◽  
Li Guo ◽  
Keming Luo
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Secondary Wall ◽  
Secondary Cell Wall ◽  
Populus Trichocarpa ◽  
Wood Formation ◽  
Myb Transcription Factor ◽  
Polymerase Chain ◽  
Xylem Fibers ◽  
R2r3 Myb

Abstract Secondary cell wall (SCW) biosynthesis during wood formation in trees is controlled by a multilevel regulatory network that coordinates the expression of substantial genes. However, few transcription factors involved in the negative regulation of secondary wall biosynthesis have been characterized in tree species. In this study, we isolated an R2R3 MYB transcription factor MYB189 from Populus trichocarpa, which is expressed predominantly in secondary vascular tissues, especially in the xylem. A novel repression motif was identified in the C-terminal region of MYB189, which indicates this factor was a transcriptional repressor. Overexpression (OE) of MYB189 in Arabidopsis and poplar resulted in a significant reduction in the contents of lignin, cellulose and hemicelluloses. Vascular development in stems of MYB189 OE lines was markedly inhibited, leading to a dramatic decrease in SCW thickness of xylem fibers. Gene expression analyses showed that most of the structural genes involved in the biosynthesis of lignin, cellulose and xylans were significantly downregulated in MYB189-overexpressing poplars compared with the wild-type control. Chromatin immunoprecipitation-quantitative real-time polymerase chain reaction and transient expression assays revealed that MYB189 could directly bind to the promoters of secondary wall biosynthetic genes to repress their expression. Together, these data suggest that MYB189 acts as a repressor to regulate SCW biosynthesis in poplar.

scholarly journals Full-length transcriptomic identification of R2R3-MYB family genes related to secondary cell wall development in Cunninghamia lanceolata (Chinese fir)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hebi Zhuang ◽  
Sun-Li Chong ◽  
Borah Priyanka ◽  
Xiao Han ◽  
Erpei Lin ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Cell Wall ◽  
Secondary Wall ◽  
Secondary Cell Wall ◽  
Evolutionary Relationship ◽  
Wood Formation ◽  
Chinese Fir ◽  
Full Length ◽  
Cell Wall Development ◽  
R2r3 Myb

Abstract Background R2R3-MYB is a class of transcription factor crucial in regulating secondary cell wall development during wood formation. The regulation of wood formation in gymnosperm has been understudied due to its large genome size. Using Single-Molecule Real-Time sequencing, we obtained full-length transcriptomic libraries from the developmental stem of Cunninghamia lanceolata, a perennial conifer known as Chinese fir. The R2R3-MYB of C. lanceolata (hereafter named as ClMYB) associated with secondary wall development were identified based on phylogenetic analysis, expression studies and functional study on transgenic line. Results The evolutionary relationship of 52 ClMYBs with those from Arabidopsis thaliana, Eucalyptus grandis, Populus trichocarpa, Oryza sativa, two gymnosperm species, Pinus taeda, and Picea glauca were established by neighbour-joining phylogenetic analysis. A large number of ClMYBs resided in the woody-expanded subgroups that predominated with the members from woody dicots. In contrast, the woody-preferential subgroup strictly carrying the members of woody dicots contained only one candidate. The results suggest that the woody-expanded subgroup emerges before the gymnosperm/angiosperm split, while most of the woody-preferential subgroups are likely lineage-specific to woody dicots. Nine candidates shared the same subgroups with the A. thaliana orthologs, with known function in regulating secondary wall development. Gene expression analysis inferred that ClMYB1/2/3/4/5/26/27/49/51 might participate in secondary wall development, among which ClMYB1/2/5/26/27/49 were significantly upregulated in the highly lignified compression wood region, reinforcing their regulatory role associated with secondary wall development. ClMYB1 was experimentally proven a transcriptional activator that localised in the nucleus. The overexpression of ClMYB1 in Nicotiana benthamiana resulted in an increased lignin deposition in the stems. The members of subgroup S4, ClMYB3/4/5 shared the ERF-associated amphiphilic repression motif with AtMYB4, which is known to repress the metabolism of phenylpropanoid derived compounds. They also carried a core motif specific to gymnosperm lineage, suggesting divergence of the regulatory process compared to the angiosperms. Conclusions This work will enrich the collection of full-length gymnosperm-specific R2R3-MYBs related to stem development and contribute to understanding their evolutionary relationship with angiosperm species.

scholarly journals EgMYB1, an R2R3 MYB transcription factor from eucalyptus negatively regulates secondary cell wall formation in Arabidopsis and poplar

2010 ◽  
Vol 188 (3) ◽  
pp. 774-786 ◽  
Author(s):  
Sylvain Legay ◽  
Pierre Sivadon ◽  
Anne-Sophie Blervacq ◽  
Nathalie Pavy ◽  
Ahmad Baghdady ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Secondary Cell Wall ◽  
Myb Transcription Factor ◽  
Cell Wall Formation ◽  
Secondary Cell Wall Formation ◽  
Wall Formation ◽  
R2r3 Myb

scholarly journals Full-Length Transcriptomic Identification of R2R3-MYB Family Genes Related to Secondary Cell Wall Development in Cunninghamia Lanceolata (Chinese Fir)

2021 ◽  
Author(s):  
Hebi Zhuang ◽  
Sun-Li Chong ◽  
Priyanka Borah ◽  
Xiao Han ◽  
Erpei Lin ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Cell Wall ◽  
Secondary Wall ◽  
Secondary Cell Wall ◽  
Evolutionary Relationship ◽  
Wood Formation ◽  
Chinese Fir ◽  
Full Length ◽  
Cell Wall Development ◽  
R2r3 Myb

Abstract Background: R2R3-MYB is a class of transcription factor crucial in regulating secondary cell wall development during wood formation. The regulation of wood formation in gymnosperm has been understudied due to its large genome size. Using Single-Molecule Real-Time sequencing, we obtained full-length transcriptomic libraries from the developmental stem of Cunninghamia lanceolata, a perennial conifer known as Chinese fir. The R2R3-MYB of C. lanceolata (hereafter named as ClMYB) associated with secondary wall development were identified based on phylogenetic analysis, expression studies and functional study on transgenic line. Results: The evolutionary relationship of 52 ClMYBs with those from Arabidopsis thaliana, Eucalyptus grandis, Populus trichocarpa, Oryza sativa, two gymnosperm species, Pinus taeda, and Picea glauca were established by neighbour-joining phylogenetic analysis. A large number of ClMYBs resided in the woody-expanded subgroups that predominated with the members from woody dicots. In contrast, the woody-preferential subgroup strictly carrying the members of woody dicots contained only one candidate. The results suggested that the woody-expanded subgroup emerges before the gymnosperm/angiosperm split, while most of the woody-preferential subgroups are likely lineage-specific to woody dicots. Nine candidates shared the same subgroups with the A. thaliana orthologs, with known function in regulating secondary wall development. Gene expression analysis inferred that ClMYB1/2/3/4/5/26/27/49/51 might participate in secondary wall development, among which ClMYB1/2/5/26/27/49 were significantly upregulated in the highly lignified compression wood region, reinforcing their regulatory role associated with secondary wall development. ClMYB1 was experimentally proven a transcriptional activator that localised in the nucleus. The overexpression of ClMYB1 in Nicotiana benthamiana resulted in an increased lignin deposition in the stems. The members of subgroup S4, ClMYB3/4/5 shared the ERF-associated amphiphilic repression motif with AtMYB4, which is known to repress the metabolism of phenylpropanoid derived compounds. They also carried a core motif specific to gymnospermm lineage, suggesting divergence of the regulatory process compared to the angiosperms.Conclusions: This work will enrich the collection of full-length gymnosperm-specific R2R3-MYBs related to stem development and contribute to understanding their evolutionary relationship with angiosperm species.

scholarly journals Functional Characterisation of the Poplar Atypical Aspartic Protease Gene PtAP66 in Wood Secondary Cell Wall Deposition

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1002
Author(s):  
Shenquan Cao ◽  
Cong Wang ◽  
Huanhuan Ji ◽  
Mengjie Guo ◽  
Jiyao Cheng ◽  
...  
Keyword(s):  
Cell Wall ◽  
Secondary Cell Wall ◽  
Fluorescent Protein ◽  
Secondary Xylem ◽  
Populus Trichocarpa ◽  
Wood Formation ◽  
Protease Gene ◽  
Cellulose Content ◽  
Transcription Analysis ◽  
Functional Characterisation

Secondary cell wall (SCW) deposition is an important process during wood formation. Although aspartic proteases (APs) have been reported to have regulatory roles in herbaceous plants, the involvement of atypical APs in SCW deposition in trees has not been reported. In this study, we characterised the Populus trichocarpa atypical AP gene PtAP66, which is involved in wood SCW deposition. Transcriptome data from the AspWood resource showed that in the secondary xylem of P. trichocarpa, PtAP66 transcripts increased from the vascular cambium to the xylem cell expansion region and maintained high levels in the SCW formation region. Fluorescent signals from transgenic Arabidopsis plant roots and transiently transformed P. trichocarpa leaf protoplasts strongly suggested that the PtAP66-fused fluorescent protein (PtAP66-GFP or PtAP66-YFP) localised in the plasma membrane. Compared with the wild-type plants, the Cas9/gRNA-induced PtAP66 mutants exhibited reduced SCW thickness of secondary xylem fibres, as suggested by the scanning electron microscopy (SEM) data. In addition, wood composition assays revealed that the cellulose content in the mutants decreased by 4.90–5.57%. Transcription analysis further showed that a loss of PtAP66 downregulated the expression of several SCW synthesis-related genes, including cellulose and hemicellulose synthesis enzyme-encoding genes. Altogether, these findings indicate that atypical PtAP66 plays an important role in SCW deposition during wood formation.

scholarly journals Analysis of NAC Domain Transcription Factor Genes of Tectona grandis L.f. Involved in Secondary Cell Wall Deposition

Genes ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 20
Author(s):  
Fernando Manuel Matias Hurtado ◽  
Maísa de Siqueira Pinto ◽  
Perla Novais de Oliveira ◽  
Diego Mauricio Riaño-Pachón ◽  
Laura Beatriz Inocente ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Secondary Cell Wall ◽  
Expression Patterns ◽  
Wood Quality ◽  
Tectona Grandis ◽  
Wood Formation ◽  
Xylem Differentiation ◽  
Transcription Factor Genes ◽  
Tectona Grandis L.F

NAC proteins are one of the largest families of plant-specific transcription factors (TFs). They regulate diverse complex biological processes, including secondary xylem differentiation and wood formation. Recent genomic and transcriptomic studies of Tectona grandis L.f. (teak), one of the most valuable hardwood trees in the world, have allowed identification and analysis of developmental genes. In the present work, T. grandis NAC genes were identified and analyzed regarding to their evolution and expression profile during wood formation. We analyzed the recently published T. grandis genome, and identified 130 NAC proteins that are coded by 107 gene loci. These proteins were classified into 23 clades of the NAC family, together with Populus, Eucalyptus, and Arabidopsis. Data on transcript expression revealed specific temporal and spatial expression patterns for the majority of teak NAC genes. RT-PCR indicated expression of VND genes (Tg11g04450-VND2 and Tg15g08390-VND4) related to secondary cell wall formation in xylem vessels of 16-year-old juvenile trees. Our findings open a way to further understanding of NAC transcription factor genes in T. grandis wood biosynthesis, while they are potentially useful for future studies aiming to improve biomass and wood quality using biotechnological approaches.

Sign in / Sign up

Export Citation Format

Share Document