scholarly journals Populus PtERF85 Balances Xylem Cell Expansion and Secondary Cell Wall Formation in Hybrid Aspen

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1971
Author(s):  
Carolin Seyfferth ◽  
Bernard A. Wessels ◽  
Jorma Vahala ◽  
Jaakko Kangasjärvi ◽  
Nicolas Delhomme ◽  
...  

Secondary growth relies on precise and specialized transcriptional networks that determine cell division, differentiation, and maturation of xylem cells. We identified a novel role for the ethylene-induced Populus ethylene response factor PtERF85 (Potri.015G023200) in balancing xylem cell expansion and secondary cell wall (SCW) formation in hybrid aspen (Populus tremula x tremuloides). Expression of PtERF85 is high in phloem and cambium cells and during the expansion of xylem cells, while it is low in maturing xylem tissue. Extending PtERF85 expression into SCW forming zones of woody tissues through ectopic expression reduced wood density and SCW thickness of xylem fibers but increased fiber diameter. Xylem transcriptomes from the transgenic trees revealed transcriptional induction of genes involved in cell expansion, translation, and growth. The expression of genes associated with plant vascular development and the biosynthesis of SCW chemical components such as xylan and lignin, was down-regulated in the transgenic trees. Our results suggest that PtERF85 activates genes related to xylem cell expansion, while preventing transcriptional activation of genes related to SCW formation. The importance of precise spatial expression of PtERF85 during wood development together with the observed phenotypes in response to ectopic PtERF85 expression suggests that PtERF85 contributes to the transition of fiber cells from elongation to secondary cell wall deposition.

2021 ◽  
Author(s):  
Carolin Seyfferth ◽  
Bernard A Wessels ◽  
Jorma Vahala ◽  
Jaakko Kangasjarvi ◽  
Nicolas Delhomme ◽  
...  

Secondary growth relies on precise and specialized transcriptional networks that determine cell division, differentiation, and maturation of xylem cells. We identify a novel role for the ethylene induced Populus ETHYLENE RESPONSE FACTOR ERF85 (Potri.015G023200) in balancing xylem cell expansion and secondary cell wall (SCW) formation in hybrid aspen (Populus tremula x tremuloides). Expression of ERF85 is high in phloem and cambium cells and during expansion of xylem cells, while it is low in maturing xylem tissue. Extending ERF85 expression into SCW forming zones of woody tissues through ectopic expression reduced wood density and SCW thickness of xylem fibers but increased fiber diameter. Xylem transcriptomes from the transgenic trees revealed transcriptional induction of genes involved in cell expansion, translation and growth. Expression of genes associated with plant vascular development and biosynthesis of SCW chemical components such as xylan and lignin, was downregulated in the transgenic trees. Our results suggest that ERF85 activates genes related with xylem cell expansion, while preventing transcriptional activation of genes related to SCW formation. The importance of precise spatial expression of ERF85 during wood development together with the observed phenotypes in response to ectopic ERF85 expression suggests that ERF85 functions as a switch between different phases of xylem differentiation during wood formation.


2019 ◽  
Vol 224 (4) ◽  
pp. 1585-1599 ◽  
Author(s):  
Bernard Wessels ◽  
Carolin Seyfferth ◽  
Sacha Escamez ◽  
Thomas Vain ◽  
Kamil Antos ◽  
...  

2019 ◽  
Vol 46 (2) ◽  
pp. 1985-2002 ◽  
Author(s):  
Amrina Shafi ◽  
Tejpal Gill ◽  
Insha Zahoor ◽  
Paramvir Singh Ahuja ◽  
Yelam Sreenivasulu ◽  
...  

2005 ◽  
Vol 137 (3) ◽  
pp. 983-997 ◽  
Author(s):  
Henrik Aspeborg ◽  
Jarmo Schrader ◽  
Pedro M. Coutinho ◽  
Mark Stam ◽  
Åsa Kallas ◽  
...  

2020 ◽  
Author(s):  
Dong Ju Lee ◽  
Il-Chul Kim ◽  
Seungwoo Jeong ◽  
Seung Gon Wi ◽  
Suk Weon Kim ◽  
...  

Abstract BackgroundThe Capsicum annuum receptor-like kinase 1 (CaRLK1) gene encodes a transmembrane protein with a cytoplasmic kinase domain and an extracellular domain. It functions as a negative regulator of plant cell death. Ectopic expression of CaRLK1 showed the hypoxia-resistance and enhanced cell division and proliferation. In this study, it was investigated which genes were controlled by ectopic expression of CaRLK1 because it decreased its average cell size of transgenic RLK1ox cells compared with that of wild-type cells (BY-2). ResultsThe average diameter (AD) of the protoplast of RLK1ox cells was about 10 µm shorter than the AD of BY-2 cells. The diameter distribution of the circular protoplasts is mainly from 20 to 40 μm (71.7%) in RLK1ox cells, whereas from 30 to 50 μm (73.0%) in BY-2 cells. Furthermore, cell volume of RLK1ox cells is also 2.5-times smaller than that of BY-2 cells. Smaller cell size of the RLK1ox cells may be related with the inhibited cell expansion because expressions of 12 expansin A genes, 6 expansin-like B genes, 2 ACC synthase genes, and 5 ACC oxidase genes were suppressed, but expressions of 7 gibberellin 2-oxidase genes were induced. The cell walls between two RLK1ox cells are approximately 138.83±4.12 nm thick on average, while those between two BY-2 cells are approximately 156.58±4.54 nm thick. Furthermore, the total content of neutral sugars in the cell wall of RLK1ox cells is less than that of BY-2 cells (about 25%). The RLK1ox cells contained 30% less glucose content than did the BY-2 cells. Thinner cell wall of the RLK1ox cells is related with the decreased cellulose biosynthesis and hemicellulose biosynthesis. Expressions of 7 CESA genes, 5 sucrose synthase 1 genes, 3 mannose-1-phosphate guanyltransferase genes, and 6 glucomannan-4-beta-mannosyltransferase genes were suppressed. The suppressed expressions of 14 polygalacturonase genes may also contribute to make the cell wall of RLK1ox cell thinner than that of BY-2 cell. ConclusionOf special emphasis is its impact of CaRLK1 gene on cell size control and cell wall thickness. Smaller cell size of the RLK1ox cells correlates with the inhibited cell expansion.


2019 ◽  
Author(s):  
Sunita Kushwah ◽  
Alicja Banasiak ◽  
Nobuyuki Nishikubo ◽  
Marta Derba-Maceluch ◽  
Mateusz Majda ◽  
...  

ABSTRACTIn dicotyledons, xyloglucan is the major hemicellulose of primary walls affecting the load-bearing framework with participation of XTH enzymes. We used loss- and gain-of function approaches to study functions of abundant cambial region expressed XTH4 and XTH9 in secondary growth. In secondarily thickened hypocotyls, these enzymes had positive effects on vessel element expansion and fiber intrusive growth. In addition, they stimulated secondary wall thickening, but reduced secondary xylem production. Cell wall analyses of inflorescence stems revealed changes in lignin, cellulose, and matrix sugar composition, indicating overall increase in secondary versus primary walls in the mutants, indicative of higher xylem production compared to wild type (since secondary walls were thinner). Intriguingly, the number of secondary cell wall layers was increased in xth9 and reduced in xth4, whereas the double mutant xth4x9 displayed intermediate number of layers. These changes correlated with certain Raman signals from the walls, indicating changes in lignin and cellulose. Secondary walls were affected also in the interfascicular fibers where neither XTH4 nor XTH9 were expressed, indicating that these effects were indirect. Transcripts involved in secondary wall biosynthesis and in cell wall integrity sensing, including THE1 and WAK2, were highly induced in the mutants, indicating that deficiency in XTH4 and XTH9 triggers cell wall integrity signaling, which, we propose, stimulates the xylem cell production and modulates secondary wall thickening. Prominent effects of XTH4 and XTH9 on secondary xylem support the hypothesis that altered xyloglucan can affect wood properties both directly and via cell wall integrity sensing.SIGNIFICANCE STATEMENTXyloglucan is a ubiquitous component of primary cell walls in all land plants but has not been so far reported in secondary walls. It is metabolized in muro by cell wall-residing enzymes - xyloglucan endotransglycosylases/hydrolases (XTHs), which are reportedly abundant in vascular tissues, but their role in these tissues is unclear. Here we report that two vascular expressed enzymes in Arabidopsis, XTH4 and XTH9 contribute to the secondary xylem cell radial expansion and intrusive elongation in secondary vascular tissues.Unexpectedly, deficiency in their activities highly affect chemistry and ultrastructure of secondary cell walls by non-cell autonomous mechanisms, including transcriptional induction of secondary wall-related biosynthetic genes and cell wall integrity sensors. These results link xyloglucan metabolism with cell wall integrity pathways, shedding new light on previous reports about prominent effects of xyloglucan metabolism on secondary walls.One sentence summaryXTH4 and XTH9 positively regulate xylem cell expansion and fiber intrusive tip growth, and their deficiency alters secondary wall formation via cell wall integrity sensing mechanisms.


2020 ◽  
Vol 110 (4) ◽  
pp. 726-733 ◽  
Author(s):  
Shakuntala E. Pillai ◽  
Chandan Kumar ◽  
Madhumita Dasgupta ◽  
Bipin K. Kumar ◽  
Sridivya Vungarala ◽  
...  

Pathogen secreted cell-wall-degrading enzymes (CWDEs) induce plant innate immune responses. The expression of rice transcription factor APETALA2/ethylene response factor-152 (OsAP2/ERF152) is enhanced in leaves upon treatment with different CWDEs and upon wounding. Ectopic expression of OsAP2/ERF152 in Arabidopsis leads to induction of immune responses such as callose deposition and upregulation of both salicylic acid- and jasmonic acid/ethylene-responsive defense genes. Arabidopsis transgenics expressing OsAP2/ERF152 exhibited resistance to infections caused by both bacterial and fungal pathogens (Pseudomonas syringae pv. tomato DC3000 and Rhizoctonia solani AG1-IA, respectively). Ectopic expression of OsAP2/ERF152 results in transient activation of mitogen-activated protein kinases 3/6 (MPK3/6), which could be leading to the induction of a broad range immunity in Arabidopsis.


2021 ◽  
Vol 22 (22) ◽  
pp. 12395
Author(s):  
Philippe Golfier ◽  
Olga Ermakova ◽  
Faride Unda ◽  
Emily K. Murphy ◽  
Jianbo Xie ◽  
...  

Cell wall recalcitrance is a major constraint for the exploitation of lignocellulosic biomass as a 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. However, knowledge about the transcriptional regulation of lignin biosynthesis in lignocellulosic feedstocks, such as Miscanthus, is limited. In Miscanthus leaves, MsSCM1 and MsMYB103 are expressed at growth stages associated with lignification. The ectopic expression of MsSCM1 and MsMYB103 in N. benthamiana leaves was sufficient to trigger secondary cell wall deposition with distinct sugar and lignin compositions. Moreover, RNA-seq analysis revealed that the transcriptional responses to MsSCM1 and MsMYB103 overexpression showed an extensive overlap with the response to the NAC master transcription factor MsSND1, but were distinct from each other, underscoring the inherent complexity of secondary cell wall formation. Furthermore, conserved and previously described promoter elements as well as novel and specific motifs could be identified from the target genes of the three transcription factors. Together, MsSCM1 and MsMYB103 represent interesting targets for manipulations of lignin content and composition in Miscanthus towards a tailored biomass.


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