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Badmi R, Payyavula RS, Bali G, Guo HB, Jawdy SS, Gunter LE, Yang X, Winkeler KA, Collins C, Rottmann WH, Yee K, Rodriguez M, Sykes RW, Decker SR, Davis MF, Ragauskas AJ, Tuskan GA, Kalluri UC. A New Calmodulin-Binding Protein Expresses in the Context of Secondary Cell Wall Biosynthesis and Impacts Biomass Properties in Populus. FRONTIERS IN PLANT SCIENCE 2018; 9:1669. [PMID: 30568662 PMCID: PMC6290091 DOI: 10.3389/fpls.2018.01669] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/26/2018] [Indexed: 05/21/2023]
Abstract
A greater understanding of biosynthesis, signaling and regulatory pathways involved in determining stem growth and secondary cell wall chemistry is important for enabling pathway engineering and genetic optimization of biomass properties. The present study describes a new functional role of PdIQD10, a Populus gene belonging to the IQ67-Domain1 family of IQD genes, in impacting biomass formation and chemistry. Expression studies showed that PdIQD10 has enhanced expression in developing xylem and tension-stressed tissues in Populus deltoides. Molecular dynamics simulation and yeast two-hybrid interaction experiments suggest interactions with two calmodulin proteins, CaM247 and CaM014, supporting the sequence-predicted functional role of the PdIQD10 as a calmodulin-binding protein. PdIQD10 was found to interact with specific Populus isoforms of the Kinesin Light Chain protein family, shown previously to function as microtubule-guided, cargo binding and delivery proteins in Arabidopsis. Subcellular localization studies showed that PdIQD10 localizes in the nucleus and plasma membrane regions. Promoter-binding assays suggest that a known master transcriptional regulator of secondary cell wall biosynthesis (PdWND1B) may be upstream of an HD-ZIP III gene that is in turn upstream of PdIQD10 gene in the transcriptional network. RNAi-mediated downregulation of PdIQD10 expression resulted in plants with altered biomass properties including higher cellulose, wall glucose content and greater biomass quantity. These results present evidence in support of a new functional role for an IQD gene family member, PdIQD10, in secondary cell wall biosynthesis and biomass formation in Populus.
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Affiliation(s)
- Raghuram Badmi
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Center for Bioenergy Innovation and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Raja S. Payyavula
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Center for Bioenergy Innovation and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Garima Bali
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Georgia Institute of Technology, Atlanta, GA, United States
| | - Hao-Bo Guo
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Sara S. Jawdy
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Center for Bioenergy Innovation and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Lee E. Gunter
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Center for Bioenergy Innovation and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Xiaohan Yang
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Center for Bioenergy Innovation and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | | | | | | | - Kelsey Yee
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Center for Bioenergy Innovation and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Miguel Rodriguez
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Center for Bioenergy Innovation and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Robert W. Sykes
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- National Renewable Energy Laboratory, Golden, CO, United States
| | - Stephen R. Decker
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- National Renewable Energy Laboratory, Golden, CO, United States
| | - Mark F. Davis
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- National Renewable Energy Laboratory, Golden, CO, United States
| | - Arthur J. Ragauskas
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Department of Chemical and Biomolecular Engineering, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Gerald A. Tuskan
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Center for Bioenergy Innovation and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Udaya C. Kalluri
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- The Center for Bioenergy Innovation and Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
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Nagle M, Déjardin A, Pilate G, Strauss SH. Opportunities for Innovation in Genetic Transformation of Forest Trees. FRONTIERS IN PLANT SCIENCE 2018; 9:1443. [PMID: 30333845 PMCID: PMC6176273 DOI: 10.3389/fpls.2018.01443] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 09/11/2018] [Indexed: 05/20/2023]
Abstract
The incorporation of DNA into plant genomes followed by regeneration of non-chimeric stable plants (transformation) remains a major challenge for most plant species. Forest trees are particularly difficult as a result of their biochemistry, aging, desire for clonal fidelity, delayed reproduction, and high diversity. We review two complementary approaches to transformation that appear to hold promise for forest trees.
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Affiliation(s)
- Michael Nagle
- Forest Ecosystems and Society, Molecular and Cellular Biology, Oregon State University, Corvallis, OR, United States
| | | | | | - Steven H. Strauss
- Forest Ecosystems and Society, Molecular and Cellular Biology, Oregon State University, Corvallis, OR, United States
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Shen Y, Li Y, Xu D, Yang C, Li C, Luo K. Molecular cloning and characterization of a brassinosteriod biosynthesis-related gene PtoDWF4 from Populus tomentosa. TREE PHYSIOLOGY 2018; 38:1424-1436. [PMID: 29579304 DOI: 10.1093/treephys/tpy027] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 02/22/2018] [Indexed: 05/19/2023]
Abstract
Brassinosteroids (BRs) as steroid hormones play an important role in plant growth and development. However, little is known about how BRs affect secondary wall biosynthesis in woody plants. In this study, we cloned and characterized PtoDWF4, a homologus gene of Arabidopsis DWF4 encoding a cytochrome P450 protein, from Populus tomentosa. qRT-PCR analysis showed that PtoDWF4 was highly expressed in stems, especially in xylem. Overexpression of PtoDWF4 (PtoDWF4-OE) in poplar promoted growth rate and biomass yield, increased area and cell layers of xylem. Transgenic plants showed a significant increase in plant height and stem diameter compared with the wild type. In contrast, the CRISPR/Cas9-generated mutation of PtoDWF4 (PtoDWF4-KO) resulted in significantly decreased biomass production in transgenic plants. Further studies revealed that constitutive expression of PtoDWF4 up-regulated the expression of secondary cell wall (SCW) biosynthesis-related genes, whereas knock-out of PtoDWF4 down-regulated their expression. Quantitative analysis of cell wall components showed a significant increase in PtoDWF4-OE lines but a reduction in PtoDWF4-KO lines compared with wild-type plants. Taken together, our results indicate that PtoDWF4 plays a positive role in improving growth rate and elevating biomass production in poplar.
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Affiliation(s)
- Yun Shen
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, China
| | - Yongli Li
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, China
| | - Dan Xu
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, China
| | - Chen Yang
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, China
| | - Chaofeng Li
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Keming Luo
- Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Chongqing Key Laboratory of Transgenic Plant and Safety Control, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, China
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
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LaMIR166a-mediated auxin biosynthesis and signalling affect somatic embryogenesis in Larix leptolepis. Mol Genet Genomics 2018; 293:1355-1363. [PMID: 29946790 DOI: 10.1007/s00438-018-1465-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 06/19/2018] [Indexed: 01/22/2023]
Abstract
Somatic embryogenesis (SE) involves complex molecular signalling pathways. Understanding molecular mechanism of SE in Larix leptolepis (L. leptolepis) can aid research on genetic improvement of gymnosperms. Previously, we obtained five LaMIR166a (miR166a precursor) -overexpression embryonic cell lines in the gymnosperm Larix leptolepis. The proliferation rates of pro-embryogenic masses in transgenic and wild-type lines were calculated. Overexpression of the miR166a precursor LaMIR166a led to slower proliferation. When pro-embryogenic masses were transferred to maturation medium, the relative expression of LaMIR166a and miR166a in the LaMIR166a-overexpression lines was higher than in the wild-type during SE, while LaHDZ31-34 expression levels also increased without negative control by miR166, suggesting that regulation of HD-ZIP III by miR166a exits stage-specific characteristics. The key indole-3-acetic acid (IAA) biosynthetic gene Nitrilase of L. leptolepis (LaNIT) was identified and the effects of miR166a on auxin biosynthesis and signalling genes were studied. During SE, LaNIT, Auxin response factor1 (LaARF1) and LaARF2 mRNA levels and IAA contents were markedly higher in LaMIR166a-overexpression lines, which revealed lower deformity rate of embryos, indicating endogenous IAA synthesis is required for somatic embryo maturation in L. leptolepis. Additionally, the IAA biosynthesis and signalling genes showed similar expression patterns to LaHDZ31-34, suggesting HD-ZIP III genes have a positive regulatory effect on LaNIT. Our results suggest miR166a and LaHDZ31-34 have important roles in auxin biosynthesis and signalling during SE, which might determine if the somatic embryo normally developed to mature in L. leptolepis.
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Edwards KD, Takata N, Johansson M, Jurca M, Novák O, Hényková E, Liverani S, Kozarewa I, Strnad M, Millar AJ, Ljung K, Eriksson ME. Circadian clock components control daily growth activities by modulating cytokinin levels and cell division-associated gene expression in Populus trees. PLANT, CELL & ENVIRONMENT 2018; 41:1468-1482. [PMID: 29520862 PMCID: PMC6001645 DOI: 10.1111/pce.13185] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 02/28/2018] [Accepted: 02/28/2018] [Indexed: 05/30/2023]
Abstract
Trees are carbon dioxide sinks and major producers of terrestrial biomass with distinct seasonal growth patterns. Circadian clocks enable the coordination of physiological and biochemical temporal activities, optimally regulating multiple traits including growth. To dissect the clock's role in growth, we analysed Populus tremula × P. tremuloides trees with impaired clock function due to down-regulation of central clock components. late elongated hypocotyl (lhy-10) trees, in which expression of LHY1 and LHY2 is reduced by RNAi, have a short free-running period and show disrupted temporal regulation of gene expression and reduced growth, producing 30-40% less biomass than wild-type trees. Genes important in growth regulation were expressed with an earlier phase in lhy-10, and CYCLIN D3 expression was misaligned and arrhythmic. Levels of cytokinins were lower in lhy-10 trees, which also showed a change in the time of peak expression of genes associated with cell division and growth. However, auxin levels were not altered in lhy-10 trees, and the size of the lignification zone in the stem showed a relative increase. The reduced growth rate and anatomical features of lhy-10 trees were mainly caused by misregulation of cell division, which may have resulted from impaired clock function.
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Affiliation(s)
- Kieron D. Edwards
- School of Biological Sciences, C.H. Waddington BuildingUniversity of EdinburghEdinburghEH9 3BFUK
| | - Naoki Takata
- Department of Plant Physiology, Umeå Plant Science CentreUmeå University901 87UmeåSweden
| | - Mikael Johansson
- Department of Plant Physiology, Umeå Plant Science CentreUmeå University901 87UmeåSweden
- RNA Biology and Molecular PhysiologyBielefeld University33615BielefeldGermany
| | - Manuela Jurca
- Department of Plant Physiology, Umeå Plant Science CentreUmeå University901 87UmeåSweden
| | - Ondřej Novák
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural ResearchInstitute of Experimental Botany ASCR and Palacký University783 71OlomoucCzech Republic
| | - Eva Hényková
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural ResearchInstitute of Experimental Botany ASCR and Palacký University783 71OlomoucCzech Republic
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science CentreSwedish University of Agricultural Sciences901 83UmeåSweden
| | - Silvia Liverani
- Department of StatisticsUniversity of WarwickCoventryCV4 7ALUK
| | - Iwanka Kozarewa
- Department of Plant Physiology, Umeå Plant Science CentreUmeå University901 87UmeåSweden
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural ResearchInstitute of Experimental Botany ASCR and Palacký University783 71OlomoucCzech Republic
| | - Andrew J. Millar
- School of Biological Sciences, C.H. Waddington BuildingUniversity of EdinburghEdinburghEH9 3BFUK
| | - Karin Ljung
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science CentreSwedish University of Agricultural Sciences901 83UmeåSweden
| | - Maria E. Eriksson
- Department of Plant Physiology, Umeå Plant Science CentreUmeå University901 87UmeåSweden
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Zhu Y, Song D, Xu P, Sun J, Li L. A HD-ZIP III gene, PtrHB4, is required for interfascicular cambium development in Populus. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:808-817. [PMID: 28905477 PMCID: PMC5814583 DOI: 10.1111/pbi.12830] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 08/26/2017] [Accepted: 08/31/2017] [Indexed: 05/07/2023]
Abstract
Wood production is dependent on the activity of the vascular cambium, which develops from the fascicular and interfascicular cambia. However, little is known about the mechanisms controlling how the vascular cambium is developed in woody species. Here, we show that PtrHB4, belonging to the Populus HD-ZIP III family, plays a critical role in the process of vascular cambium development. PtrHB4 was specifically expressed in shoot tip and stem vascular tissue at an early developmental stage. Repression of PtrHB4 caused defects in the development of the secondary vascular system due to failures in interfascicular cambium formation. By contrast, overexpression of PtrHB4 induced cambium activity and xylem differentiation during secondary vascular development. Transcriptional analysis of PtrHB4 repressed plants indicated that auxin response and cell proliferation were affected in the formation of the interfascicular cambium. Taken together, these results suggest that PtrHB4 is required for interfascicular cambium formation to develop the vascular cambium in woody species.
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Affiliation(s)
- Yingying Zhu
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologyShanghai Institutes for Biological SciencesChinese Academy of SciencesShanghaiChina
| | - Dongliang Song
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologyShanghai Institutes for Biological SciencesChinese Academy of SciencesShanghaiChina
| | - Peng Xu
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologyShanghai Institutes for Biological SciencesChinese Academy of SciencesShanghaiChina
- Present address:
Warnell School of Forestry and Natural Resources and Department of GeneticsUniversity of GeorgiaAthensGA30602USA
| | - Jiayan Sun
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologyShanghai Institutes for Biological SciencesChinese Academy of SciencesShanghaiChina
| | - Laigeng Li
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologyShanghai Institutes for Biological SciencesChinese Academy of SciencesShanghaiChina
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Genome-Wide Identification and Expression Analysis of the HD-Zip Gene Family in Wheat (Triticum aestivum L.). Genes (Basel) 2018; 9:genes9020070. [PMID: 29389910 PMCID: PMC5852566 DOI: 10.3390/genes9020070] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 01/23/2018] [Accepted: 01/26/2018] [Indexed: 11/16/2022] Open
Abstract
The homeodomain-leucine zipper (HD-Zip) gene family, as plant-specific transcription factors, plays an important role in plant development and growth as well as in the response to diverse stresses. Although HD-Zip genes have been extensively studied in many plants, they had not yet been studied in wheat, especially those involved in response to abiotic stresses. In this study, 46 wheat HD-Zip genes were identified using a genome-wide search method. Phylogenetic analysis classified these genes into four groups, numbered 4, 5, 17 and 20 respectively. In total, only three genes with A, B and D homoeologous copies were identified. Furthermore, the gene interaction networks found that the TaHDZ genes played a critical role in the regulatory pathway of organ development and osmotic stress. Finally, the expression profiles of the wheat HD-Zips in different tissues and under various abiotic stresses were investigated using the available RNA sequencing (RNA-Seq) data and then validated by quantitative real-time polymerase chain reaction (qRT-PCR) to obtain the tissue-specific and stress-responsive candidates. This study systematically identifies the HD-Zip gene family in wheat at the genome-wide level, providing important candidates for further functional analysis and contributing to the better understanding of the molecular basis of development and stress tolerance in wheat.
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Affiliation(s)
- Raili Ruonala
- Institute of Biotechnology and Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland
- The Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, United Kingdom;, ,
| | - Donghwi Ko
- The Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, United Kingdom;, ,
| | - Ykä Helariutta
- Institute of Biotechnology and Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland
- The Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, United Kingdom;, ,
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Ragni L, Greb T. Secondary growth as a determinant of plant shape and form. Semin Cell Dev Biol 2017; 79:58-67. [PMID: 28864343 DOI: 10.1016/j.semcdb.2017.08.050] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 07/26/2017] [Accepted: 08/28/2017] [Indexed: 02/06/2023]
Abstract
Plants are the primary producers of biomass on earth. As an almost stereotypic feature, higher plants generate continuously growing bodies mediated by the activity of different groups of stem cells, the meristems. Shoot and root thickening is one of the fundamental growth processes determining form and function of these bodies. Mediated by a group of cylindrical meristems located below organ surfaces, vascular and protective tissues are continuously generated in a highly plastic manner, a competence essential for the survival in an ever changing environment. Acknowledging the fundamental role of this process, which is overall designated as secondary growth, we discuss in this review our current knowledge about the evolution and molecular regulation of the vascular cambium. The cambium is the meristem responsible for the formation of wood and bast, the two types of vascular tissues important for long-distance transport of water and assimilates, respectively. Although regulatory patterns are only beginning to emerge, we show that cambium activity represents a highly rewarding model for studying cell fate decisions, tissue patterning and differentiation, which has experienced an outstanding phylogenetic diversification.
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Affiliation(s)
- Laura Ragni
- ZMBP, University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
| | - Thomas Greb
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany.
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Ramachandran P, Carlsbecker A, Etchells JP. Class III HD-ZIPs govern vascular cell fate: an HD view on patterning and differentiation. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:55-69. [PMID: 27794018 DOI: 10.1093/jxb/erw370] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Plant vasculature is required for the transport of water and solutes throughout the plant body. It is constituted of xylem, specialized for transport of water, and phloem, that transports photosynthates. These two differentiated tissues are specified early in development and arise from divisions in the procambium, which is the vascular meristem during primary growth. During secondary growth, the xylem and phloem are further expanded via differentiation of cells derived from divisions in the cambium. Almost all of the developmental fate decisions in this process, including vascular specification, patterning, and differentiation, are regulated by transcription factors belonging to the class III homeodomain-leucine zipper (HD-ZIP III) family. This review draws together the literature describing the roles that these genes play in vascular development, looking at how HD-ZIP IIIs are regulated, and how they in turn influence other regulators of vascular development. Themes covered vary, from interactions between HD-ZIP IIIs and auxin, cytokinin, and brassinosteroids, to the requirement for exquisite spatial and temporal regulation of HD-ZIP III expression through miRNA-mediated post-transcriptional regulation, and interactions with other transcription factors. The literature described places the HD-ZIP III family at the centre of a complex network required for initiating and maintaining plant vascular tissues.
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Affiliation(s)
- Prashanth Ramachandran
- Physiological Botany, Department of Organismal Biology and Linnean Centre for Plant Biology in Uppsala, Uppsala University, Ulls väg 24E, SE-756 51 Uppsala, Sweden
| | - Annelie Carlsbecker
- Physiological Botany, Department of Organismal Biology and Linnean Centre for Plant Biology in Uppsala, Uppsala University, Ulls väg 24E, SE-756 51 Uppsala, Sweden
| | - J Peter Etchells
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
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Soler M, Plasencia A, Lepikson-Neto J, Camargo ELO, Dupas A, Ladouce N, Pesquet E, Mounet F, Larbat R, Grima-Pettenati J. The Woody-Preferential Gene EgMYB88 Regulates the Biosynthesis of Phenylpropanoid-Derived Compounds in Wood. FRONTIERS IN PLANT SCIENCE 2016; 7:1422. [PMID: 27713753 PMCID: PMC5032791 DOI: 10.3389/fpls.2016.01422] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 09/06/2016] [Indexed: 05/19/2023]
Abstract
Comparative phylogenetic analyses of the R2R3-MYB transcription factor family revealed that five subgroups were preferentially found in woody species and were totally absent from Brassicaceae and monocots (Soler et al., 2015). Here, we analyzed one of these subgroups (WPS-I) for which no gene had been yet characterized. Most Eucalyptus members of WPS-I are preferentially expressed in the vascular cambium, the secondary meristem responsible for tree radial growth. We focused on EgMYB88, which is the most specifically and highly expressed in vascular tissues, and showed that it behaves as a transcriptional activator in yeast. Then, we functionally characterized EgMYB88 in both transgenic Arabidopsis and poplar plants overexpressing either the native or the dominant repression form (fused to the Ethylene-responsive element binding factor-associated Amphiphilic Repression motif, EAR). The transgenic Arabidopsis lines had no phenotype whereas the poplar lines overexpressing EgMYB88 exhibited a substantial increase in the levels of the flavonoid catechin and of some salicinoid phenolic glycosides (salicortin, salireposide, and tremulacin), in agreement with the increase of the transcript levels of landmark biosynthetic genes. A change in the lignin structure (increase in the syringyl vs. guaiacyl, S/G ratio) was also observed. Poplar lines overexpressing the EgMYB88 dominant repression form did not show a strict opposite phenotype. The level of catechin was reduced, but the levels of the salicinoid phenolic glycosides and the S/G ratio remained unchanged. In addition, they showed a reduction in soluble oligolignols containing sinapyl p-hydroxybenzoate accompanied by a mild reduction of the insoluble lignin content. Altogether, these results suggest that EgMYB88, and more largely members of the WPS-I group, could control in cambium and in the first layers of differentiating xylem the biosynthesis of some phenylpropanoid-derived secondary metabolites including lignin.
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Affiliation(s)
- Marçal Soler
- Laboratoire de Recherche en Sciences Végétales, Centre National de la Recherche Scientifique, Université de Toulouse III, Paul SabatierToulouse, France
| | - Anna Plasencia
- Laboratoire de Recherche en Sciences Végétales, Centre National de la Recherche Scientifique, Université de Toulouse III, Paul SabatierToulouse, France
| | - Jorge Lepikson-Neto
- Laboratoire de Recherche en Sciences Végétales, Centre National de la Recherche Scientifique, Université de Toulouse III, Paul SabatierToulouse, France
| | - Eduardo L. O. Camargo
- Laboratoire de Recherche en Sciences Végétales, Centre National de la Recherche Scientifique, Université de Toulouse III, Paul SabatierToulouse, France
| | - Annabelle Dupas
- Laboratoire de Recherche en Sciences Végétales, Centre National de la Recherche Scientifique, Université de Toulouse III, Paul SabatierToulouse, France
| | - Nathalie Ladouce
- Laboratoire de Recherche en Sciences Végétales, Centre National de la Recherche Scientifique, Université de Toulouse III, Paul SabatierToulouse, France
| | | | - Fabien Mounet
- Laboratoire de Recherche en Sciences Végétales, Centre National de la Recherche Scientifique, Université de Toulouse III, Paul SabatierToulouse, France
| | - Romain Larbat
- “Agronomie et Environnement” Nancy-Colmar, Institut National de la Recherche Agronomique, Université de Lorraine UMR1121Vandœuvre-lès-Nancy, France
| | - Jacqueline Grima-Pettenati
- Laboratoire de Recherche en Sciences Végétales, Centre National de la Recherche Scientifique, Université de Toulouse III, Paul SabatierToulouse, France
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Růžička K, Ursache R, Hejátko J, Helariutta Y. Xylem development - from the cradle to the grave. THE NEW PHYTOLOGIST 2015; 207:519-35. [PMID: 25809158 DOI: 10.1111/nph.13383] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 02/21/2015] [Indexed: 05/06/2023]
Abstract
The development and growth of plants, as well as their successful adaptation to a variety of environments, is highly dependent on the conduction of water, nutrients and other important molecules throughout the plant body. Xylem is a specialized vascular tissue that serves as a conduit of water and minerals and provides mechanical support for upright growth. Wood, also known as secondary xylem, constitutes the major part of mature woody stems and roots. In the past two decades, a number of key factors including hormones, signal transducers and (post)transcriptional regulators have been shown to control xylem formation. We outline the main mechanisms shown to be essential for xylem development in various plant species, with an emphasis on Arabidopsis thaliana, as well as several tree species where xylem has a long history of investigation. We also summarize the processes which have been shown to be instrumental during xylem maturation. This includes mechanisms of cell wall formation and cell death which collectively complete xylem cell fate.
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Affiliation(s)
- Kamil Růžička
- Department of Functional Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 25, Brno, CZ-62500, Czech Republic
| | - Robertas Ursache
- Sainsbury Laboratory, University of Cambridge, Bateman Street, Cambridge, CB2 1LR, UK
| | - Jan Hejátko
- Department of Functional Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 25, Brno, CZ-62500, Czech Republic
| | - Ykä Helariutta
- Sainsbury Laboratory, University of Cambridge, Bateman Street, Cambridge, CB2 1LR, UK
- Institute of Biotechnology, University of Helsinki, PO Box 65, Helsinki, FIN-00014, Finland
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Abstract
Wood (also termed secondary xylem) is the most abundant biomass produced by plants, and is one of the most important sinks for atmospheric carbon dioxide. The development of wood begins with the differentiation of the lateral meristem, vascular cambium, into secondary xylem mother cells followed by cell expansion, secondary wall deposition, programmed cell death, and finally heartwood formation. Significant progress has been made in the past decade in uncovering the molecular players involved in various developmental stages of wood formation in tree species. Hormonal signalling has been shown to play critical roles in vascular cambium cell proliferation and a peptide-receptor-transcription factor regulatory mechanism similar to that controlling the activity of apical meristems is proposed to be involved in the maintenance of vascular cambium activity. It has been demonstrated that the differentiation of vascular cambium into xylem mother cells is regulated by plant hormones and HD-ZIP III transcription factors, and the coordinated activation of secondary wall biosynthesis genes during wood formation is mediated by a transcription network encompassing secondary wall NAC and MYB master switches and their downstream transcription factors. Most genes encoding the biosynthesis enzymes for wood components (cellulose, xylan, glucomannan, and lignin) have been identified in poplar and a number of them have been functionally characterized. With the availability of genome sequences of tree species from both gymnosperms and angiosperms, and the identification of a suite of wood-associated genes, it is expected that our understanding of the molecular control of wood formation in trees will be greatly accelerated.
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Affiliation(s)
- Zheng-Hua Ye
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Ruiqin Zhong
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
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Liu L, Zinkgraf M, Petzold HE, Beers EP, Filkov V, Groover A. The Populus ARBORKNOX1 homeodomain transcription factor regulates woody growth through binding to evolutionarily conserved target genes of diverse function. THE NEW PHYTOLOGIST 2015; 205:682-94. [PMID: 25377848 DOI: 10.1111/nph.13151] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Accepted: 10/01/2014] [Indexed: 05/28/2023]
Abstract
The class I KNOX homeodomain transcription factor ARBORKNOX1 (ARK1) is a key regulator of vascular cambium maintenance and cell differentiation in Populus. Currently, basic information is lacking concerning the distribution, functional characteristics, and evolution of ARK1 binding in the Populus genome. Here, we used chromatin immunoprecipitation sequencing (ChIP-seq) technology to identify ARK1 binding loci genome-wide in Populus. Computational analyses evaluated the distribution of ARK1 binding loci, the function of genes associated with bound loci, the effect of ARK1 binding on transcript levels, and evolutionary conservation of ARK1 binding loci. ARK1 binds to thousands of loci which are highly enriched proximal to the transcriptional start sites of genes of diverse functions. ARK1 target genes are significantly enriched in paralogs derived from the whole-genome salicoid duplication event. Both ARK1 and a maize (Zea mays) homolog, KNOTTED1, preferentially target evolutionarily conserved genes. However, only a small portion of ARK1 target genes are significantly differentially expressed in an ARK1 over-expression mutant. This study describes the functional characteristics and evolution of DNA binding by a transcription factor in an undomesticated tree, revealing complexities similar to those shown for transcription factors in model animal species.
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Affiliation(s)
- Lijun Liu
- Pacific Southwest Research Station, USDA Forest Service, Davis, CA, 95618, USA
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Kajala K, Ramakrishna P, Fisher A, C. Bergmann D, De Smet I, Sozzani R, Weijers D, Brady SM. Omics and modelling approaches for understanding regulation of asymmetric cell divisions in arabidopsis and other angiosperm plants. ANNALS OF BOTANY 2014; 113:1083-1105. [PMID: 24825294 PMCID: PMC4030820 DOI: 10.1093/aob/mcu065] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 03/06/2014] [Indexed: 05/23/2023]
Abstract
BACKGROUND Asymmetric cell divisions are formative divisions that generate daughter cells of distinct identity. These divisions are coordinated by either extrinsic ('niche-controlled') or intrinsic regulatory mechanisms and are fundamentally important in plant development. SCOPE This review describes how asymmetric cell divisions are regulated during development and in different cell types in both the root and the shoot of plants. It further highlights ways in which omics and modelling approaches have been used to elucidate these regulatory mechanisms. For example, the regulation of embryonic asymmetric divisions is described, including the first divisions of the zygote, formative vascular divisions and divisions that give rise to the root stem cell niche. Asymmetric divisions of the root cortex endodermis initial, pericycle cells that give rise to the lateral root primordium, procambium, cambium and stomatal cells are also discussed. Finally, a perspective is provided regarding the role of other hormones or regulatory molecules in asymmetric divisions, the presence of segregated determinants and the usefulness of modelling approaches in understanding network dynamics within these very special cells. CONCLUSIONS Asymmetric cell divisions define plant development. High-throughput genomic and modelling approaches can elucidate their regulation, which in turn could enable the engineering of plant traits such as stomatal density, lateral root development and wood formation.
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Affiliation(s)
- Kaisa Kajala
- Department of Plant Biology and Genome Center, UC Davis, Davis, CA 95616, USA
| | - Priya Ramakrishna
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD, UK
| | - Adam Fisher
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Dominique C. Bergmann
- Howard Hughes Medical Institute and Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Ive De Smet
- Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD, UK
- Department of Plant Systems Biology, VIB, Technologiepark 927, B-9052 Ghent, Belgium
- Department of Plant Biotechnology and Genetics, Ghent University, Technologiepark 927, B-9052 Ghent, Belgium
| | - Rosangela Sozzani
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703HA Wageningen, The Netherlands
| | - Siobhan M. Brady
- Department of Plant Biology and Genome Center, UC Davis, Davis, CA 95616, USA
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Zhang L, Yang T, Li X, Hao H, Xu S, Cheng W, Sun Y, Wang C. Cloning and characterization of a novel Athspr promoter specifically active in vascular tissue. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 78:88-96. [PMID: 24675528 DOI: 10.1016/j.plaphy.2014.02.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 02/22/2014] [Indexed: 06/03/2023]
Abstract
The vascular system--xylem, phloem and the cambium--is essential for water supply, nutrient transport, and physical support in higher plants. Although it is known that vascular-specific gene expression is regulated by cis-acting regulatory sequences in promoters, it is largely unknown how many regulatory elements exist and what their roles are in promoters. To understand the regulatory elements of vascular-specific promoters and their roles in vascular development, a T-DNA insertion mutant showing delayed growth and diminished resistance to environmental stress was isolated using promoter trap strategy. The novel gene, Arabidopsis thaliana heat shock protein-related (Athspr), was cloned from Arabidopsis ecotype C24. Strong GUS (β-glucuronidase) staining in the original promoter trap line was found in the vascular tissues of all organs in the mutant. The Athspr promoter was cloned and fused with GUS and eGFP (enhanced green fluorescent protein) reporter genes to verify its vascular-specific expression in Arabidopsis. Further histochemical analysis in transgenic plants demonstrated a similar GUS expression pattern in the vascular tissues. In addition, ATHSPR-eGFP driven by Athspr promoter was observed in vascular bundles of the transgenic seedling roots. Finally, comparative analysis with promoter motifs from 37 genes involved in vascular development revealed that Athspr and all other promoters active in vascular tissues contained regulatory elements responding to phytohormones, light, biotic and abiotic stresses, as well as those regulating tissue-specific expression. These results demonstrated that the Athspr promoter has a vascular tissue-specific activity and Athspr may have multiple functions in vascular development and resistance against various stresses.
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Affiliation(s)
- Liang Zhang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Tao Yang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Xiaoying Li
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Hongyan Hao
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Shengtao Xu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Wei Cheng
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yingli Sun
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Chongying Wang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
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Knockdown of OsHox33, a member of the class III homeodomain-leucine zipper gene family, accelerates leaf senescence in rice. SCIENCE CHINA-LIFE SCIENCES 2013; 56:1113-23. [DOI: 10.1007/s11427-013-4565-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 09/26/2013] [Indexed: 01/24/2023]
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68
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Xu P, Kong Y, Li X, Li L. Identification of molecular processes needed for vascular formation through transcriptome analysis of different vascular systems. BMC Genomics 2013; 14:217. [PMID: 23548001 PMCID: PMC3620544 DOI: 10.1186/1471-2164-14-217] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 03/22/2013] [Indexed: 11/24/2022] Open
Abstract
Background Vascular system formation has been studied through molecular and genetic approaches in Arabidopsis, a herbaceous dicot that is used as a model system. Different vascular systems have developed in other plants such as crops and trees. Uncovering shared mechanisms underlying vascular development by transcriptome analysis of different vascular systems may help to transfer knowledge acquired from Arabidopsis to other economically important species. Results Conserved vascular genes and biological processes fundamental to vascular development were explored across various plants. Through comparative transcriptome analysis, 226 genes from Arabidopsis, 217 genes from poplar and 281 genes from rice were identified as constituting 107 conserved vascular gene groups. These gene groups are expressed mainly in vascular tissues and form a complex coexpression network with multiple functional connections. To date, only half of the groups have been experimentally investigated. The conserved vascular gene groups were classified into 9 essential processes for vascular development. 18 groups (17%) lack of annotations were classified as having unknown functions. Conclusion The study provides a map of fundamental biological processes conserved across different vascular systems. It identifies gaps in the experimental investigation of pathways active in vascular formation, which if explored, could lead to a more complete understanding of vascular development.
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Affiliation(s)
- Peng Xu
- National Key Laboratory of Plant Molecular Genetics and Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Rd, Shanghai 200032, China
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