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Zhou H, Song X, Lu MZ. Growth-regulating factor 15-mediated vascular cambium differentiation positively regulates wood formation in hybrid poplar (Populus alba × P. glandulosa). Front Plant Sci 2024; 15:1343312. [PMID: 38425797 PMCID: PMC10902170 DOI: 10.3389/fpls.2024.1343312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/01/2024] [Indexed: 03/02/2024]
Abstract
Introduction Hybrid poplars are industrial trees in China. An understanding of the molecular mechanism underlying wood formation in hybrid poplars is necessary for molecular breeding. Although the division and differentiation of vascular cambial cells is important for secondary growth and wood formation, the regulation of this process is largely unclear. Methods In this study, mPagGRF15 OE and PagGRF15-SRDX transgenic poplars were generated to investigate the function of PagGRF15. RNA-seq and qRT-PCR were conducted to analyze genome-wide gene expression, while ChIP‒seq and ChIP-PCR were used to identified the downstream genes regulated by PagGRF15. Results and discussion We report that PagGRF15 from hybrid poplar (Populus alba × P. glandulosa), a growth-regulating factor, plays a critical role in the regulation of vascular cambium activity. PagGRF15 was expressed predominantly in the cambial zone of vascular tissue. Overexpression of mPagGRF15 (the mutated version of GRF15 in the miR396 target sequence) in Populus led to decreased plant height and internode number. Further stem cross sections showed that the mPagGRF15 OE plants exhibited significant changes in vascular pattern with an increase in xylem and a reduction in phloem. In addition, cambium cell files were decreased in the mPagGRF15 OE plants. However, dominant suppression of the downstream genes of PagGRF15 using PagGRF15-SRDX showed an opposite phenotype. Based on the RNA-seq and ChIP-seq results, combining qRT-PCR and ChIP-PCR analysis, candidate genes, such as WOX4b, PXY and GID1.3, were obtained and found to be mainly involved in cambial activity and xylem differentiation. Accordingly, we speculated that PagGRF15 functions as a positive regulator mediating xylem differentiation by repressing the expression of the WOX4a and PXY genes to set the pace of cambial activity. In contrast, PagGRF15 mediated the GA signaling pathway by upregulating GID1.3 expression to stimulate xylem differentiation. This study provides valuable information for further studies on vascular cambium differentiation mechanisms and genetic improvement of the specific gravity of wood in hybrid poplars.
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Affiliation(s)
- Houjun Zhou
- The Engineering Research Institute of Agriculture and Forestry, Ludong University, Yantai, China
| | - Xueqin Song
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Meng-Zhu Lu
- State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
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2
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Cunha Neto IL, Onyenedum JG. Ectopic cambia: Connections between natural and experimental vascular mutants. Am J Bot 2023; 110:e16246. [PMID: 37750551 DOI: 10.1002/ajb2.16246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/18/2023] [Accepted: 09/19/2023] [Indexed: 09/27/2023]
Affiliation(s)
- Israel L Cunha Neto
- Department of Environmental Studies, New York University, New York, 10012, NY, USA
| | - Joyce G Onyenedum
- Department of Environmental Studies, New York University, New York, 10012, NY, USA
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3
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Kulkarni CC, Cholin SS, Bajpai AK, Ondrasek G, Mesta RK, Rathod S, Patil HB. Comparative Root Transcriptome Profiling and Gene Regulatory Network Analysis between Eastern and Western Carrot ( Daucus carota L.) Cultivars Reveals Candidate Genes for Vascular Tissue Patterning. Plants (Basel) 2023; 12:3449. [PMID: 37836190 PMCID: PMC10575051 DOI: 10.3390/plants12193449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 09/26/2023] [Accepted: 09/28/2023] [Indexed: 10/15/2023]
Abstract
Carrot (Daucus carota L.) is a highly consumed vegetable rich in carotenoids, known for their potent antioxidant, anti-inflammatory, and immune-protecting properties. While genetic and molecular studies have largely focused on wild and Western carrot cultivars (cvs), little is known about the evolutionary interactions between closely related Eastern and Western cvs. In this study, we conducted comparative transcriptome profiling of root tissues from Eastern (UHSBC-23-1) and Western (UHSBC-100) carrot cv. to better understand differentially expressed genes (DEGs) associated with storage root development and vascular cambium (VC) tissue patterning. Through reference-guided TopHat mapping, we achieved an average mapping rate of 73.87% and identified a total of 3544 DEGs (p < 0.05). Functional annotation and gene ontology classification revealed 97 functional categories, including 33 biological processes, 19 cellular components, 45 metabolic processes, and 26 KEGG pathways. Notably, Eastern cv. exhibited enrichment in cell wall, plant-pathogen interaction, and signal transduction terms, while Western cv. showed dominance in photosynthesis, metabolic process, and carbon metabolism terms. Moreover, constructed gene regulatory network (GRN) for both cvs. obtained orthologs with 1222 VC-responsive genes of Arabidopsis thaliana. In Western cv, GRN revealed VC-responsive gene clusters primarily associated with photosynthetic processes and carbon metabolism. In contrast, Eastern cv. exhibited a higher number of stress-responsive genes, and transcription factors (e.g., MYB15, WRKY46, AP2/ERF TF connected via signaling pathways with NAC036) were identified as master regulators of xylem vessel differentiation and secondary cell wall thickening. By elucidating the comparative transcriptome profiles of Eastern and Western cvs. for the first time, our study provides valuable insights into the differentially expressed genes involved in root development and VC tissue patterning. The identification of key regulatory genes and their roles in these processes represents a significant advancement in our understanding of the evolutionary relations and molecular mechanisms underlying secondary growth of carrot and regulation by vascular cambium.
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Affiliation(s)
- Chaitra C. Kulkarni
- Plant Molecular Biology Lab (DBT-BIOCARe), Department of Biotechnology & Crop Improvement, College of Horticulture, University of Horticultural Sciences, Bagalkot 587103, Karnataka, India;
- Kittur Rani Chennamma College of Horticulture, Arabhavi, Gokak 591218, Belgaum Dt., Karnataka, India
- University of Horticultural Sciences, Bagalkot 587103, Karnataka, India
| | - Sarvamangala S. Cholin
- Plant Molecular Biology Lab (DBT-BIOCARe), Department of Biotechnology & Crop Improvement, College of Horticulture, University of Horticultural Sciences, Bagalkot 587103, Karnataka, India;
- University of Horticultural Sciences, Bagalkot 587103, Karnataka, India
| | - Akhilesh K. Bajpai
- Shodhaka Life Sciences Pvt. Ltd., Electronic City, Phase-I, Bengaluru 560100, Karnataka, India
| | - Gabrijel Ondrasek
- Department of Soil Amelioration, Faculty of Agriculture, University of Zagreb, 10000 Zagreb, Croatia
| | - R. K. Mesta
- University of Horticultural Sciences, Bagalkot 587103, Karnataka, India
| | - Santosha Rathod
- Indian Institute of Rice Research, Hyderabad 500030, Telangana, India
| | - H. B. Patil
- University of Horticultural Sciences, Bagalkot 587103, Karnataka, India
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4
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Xie Z, Gui J, Zhong Y, Li B, Sun J, Shen J, Li L. Screening genome-editing knockouts reveals the receptor-like kinase ASX role in regulations of secondary xylem development in Populus. New Phytol 2023; 238:1972-1985. [PMID: 36922397 DOI: 10.1111/nph.18881] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 03/07/2023] [Indexed: 05/04/2023]
Abstract
In trees, secondary xylem development is essential for the growth of perennial stem increments. Many signals regulate the process of development, but our knowledge of the molecular components involved in signal transduction is still limited. In this study, we identified Attenuation of Secondary Xylem (ASX) knockouts by screening genome-editing knockouts of xylem-expressed receptor-like kinases (RLKs) in Populus. The ASX role in secondary xylem development in Populus was discovered using biochemical, cellular, and genomic analyses. The ASX knockout plants had abnormal secondary stem growth but had little effect on shoot apical primary growth. ASX and SOMATIC EMBRYOGENESIS RECEPTOR KINASE (SERK)2/4 were co-precipitated in developing xylem. Through their interaction, ASX is phosphorylated by SERK. Transcriptome analysis of developing xylem revealed that ASX deficiency inhibited the transcriptional activity of genes involved in xylem differentiation and secondary cell wall formation. By forming a complex, ASX and SERK may function as a signaling module for signal transduction required in the regulation of secondary xylem development in trees. This study shows that ASX, which encodes a RLKs, is required for secondary xylem development and sheds light on regulatory signals found in tree stem secondary growth.
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Affiliation(s)
- Zhi Xie
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Jinshan Gui
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, China
| | - Yu Zhong
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Bo Li
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiayan Sun
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Junhui Shen
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Laigeng Li
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
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Dong J, Wang Y, Xu L, Li B, Wang K, Ying J, He Q, Liu L. RsCLE22a regulates taproot growth through an auxin signaling-related pathway in radish (Raphanus sativus L.). J Exp Bot 2023; 74:233-250. [PMID: 36239471 DOI: 10.1093/jxb/erac406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 10/12/2022] [Indexed: 06/16/2023]
Abstract
CLAVATA3/EMBRYO SURROUNDING REGION-related (CLE) peptides are a class of small molecules involved in plant growth and development. Although radish (Raphanus sativus) is an important root vegetable crop worldwide, the functions of CLE peptides in its taproot formation remain elusive. Here, a total of 48 RsCLE genes were identified from the radish genome. RNA in situ hybridization showed that RsCLE22a gene was highly expressed in the vascular cambium. Overexpression of RsCLE22a inhibited root growth by impairing stem cell proliferation in Arabidopsis, and radish plants with exogenous supplementation of RsCLE22 peptide (CLE22p) showed a similar phenotype. The vascular cambial activity was increased in RsCLE22a-silenced plants. Transcriptome analysis revealed that CLE22p altered the expression of several genes involved in meristem development and hormone signal transduction in radish. Immunolocalization results showed that CLE22p increased auxin accumulation in vascular cambium. Yeast one-hybrid and dual-luciferase assays showed that the WUSCHEL-RELATED HOMEOBOX 4 (RsWOX4) binds to RsCLE22a promoter and activates its transcription. The expression level of RsWOX4 was related to vascular cambial activity and was regulated by auxin. Furthermore, a RsCLE22a-RsWOX4 module is proposed to regulate taproot vascular cambium activity through an auxin signaling-related pathway in radish. These findings provide novel insights into the regulation of root growth in a horticultural crop.
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Affiliation(s)
- Junhui Dong
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Yan Wang
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Liang Xu
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Bingshuang Li
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Kai Wang
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Jiali Ying
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Qing He
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Liwang Liu
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Horticultural Crop Biology and Genetic Improvement (East China) of MOAR, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
- College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou 225009, China
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Wang Y, Hao Y, Guo Y, Shou H, Du J. PagDET2 promotes cambium cell division and xylem differentiation in poplar stem. Front Plant Sci 2022; 13:923530. [PMID: 36092441 PMCID: PMC9459238 DOI: 10.3389/fpls.2022.923530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
Secondary growth of the woody tree stem is governed by meristematic cell division and differentiation in the vascular cambium. Multiple hormonal signals and endogenous developmental programs regulate vascular cambium activity. Brassinosteroids (BRs) significantly promote secondary stem growth and wood formation in poplar trees. However, the underlying regulatory mechanisms of BRs within the vascular tissue remain unclear. Genetic and anatomical approaches were used here to elucidate the role of PagDET2, the rate-limiting enzyme for BRs biosynthesis, in regulating secondary vascular cambium activity in Populus. This study showed that the elevated endogenous castasterone (CS) levels in tree stems through overexpressing PagDET2 could enhance cambium meristem cell activity and xylem (XY) differentiation to promote secondary stem growth. RNA-seq analysis revealed that genes involved in BRs response, vascular cambium cell division, XY differentiation, and secondary cell wall synthesis were up-regulated.
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Affiliation(s)
- Yao Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yi Hao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yakun Guo
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, Hangzhou, China
| | - Huixia Shou
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Juan Du
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
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7
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Bruzinga WSDJS, Ribeiro LM, Nunes YRF, Pimenta LPS, Almeida MATD, Mendes MGA, Mercadante-Simões MO. Ontogenesis of Resin Ducts and Secretory Process in Protium spruceanum (Burseraceae) Stems. Microsc Microanal 2022; 28:1-12. [PMID: 35314015 DOI: 10.1017/s1431927622000459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The objective of this work was to characterize the ontogenesis of Protium spruceanum secretory ducts, to evaluate the effects of seasonality on that process, and to characterize the chemical nature of the resin. Morphometric, anatomical, micromorphometric, histochemical, and ultrastructural evaluations of shoot apexes and chemical analyses of the resin were performed. The ducts of schizolysigenous origin are distributed in the primary and secondary phloem. The subsecretory tissue is meristematic and can restore the secretory epithelium. Secretory epithelial cells have wall thickening resembling that of the Casparian strip that regulates secretion reflux. The main resin compounds are pentacyclic triterpenoids, α- and β-amyrins, and α- and β-amyrenones, which are reported here for the first time for this species. The presence of electron-dense and electron-opaque structures, in the secretory epithelial cells, are compatible with the triterpenes and mucilage identified in the resin. Rising temperatures, rainfall, and increasing day length induce the formation of ducts in the vascular cambium throughout Spring/Summer. The abundant production of resin rich in pentacyclic triterpenes indicates the potential use of the species for medicinal and cosmetic purposes. The understanding that secretory processes are concentrated during the Spring/Summer seasons will contribute to the definition of resin extraction management strategies.
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Affiliation(s)
| | - Leonardo Monteiro Ribeiro
- Departamento de Biologia Geral, Universidade Estadual de Montes Claros, Montes Claros, MG39401-089, Brazil
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Rahimi A, Karami O, Lestari AD, de Werk T, Amakorová P, Shi D, Novák O, Greb T, Offringa R. Control of cambium initiation and activity in Arabidopsis by the transcriptional regulator AHL15. Curr Biol 2022; 32:1764-1775.e3. [PMID: 35294866 DOI: 10.1016/j.cub.2022.02.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 12/10/2021] [Accepted: 02/22/2022] [Indexed: 01/10/2023]
Abstract
Plant secondary growth, which is the basis of wood formation, includes the production of secondary xylem, which is derived from meristematic cambium cells embedded in vascular tissue. Here, we identified an important role for the Arabidopsis thaliana (Arabidopsis) AT-HOOK MOTIF CONTAINING NUCLEAR LOCALIZED 15 (AHL15) transcriptional regulator in controlling vascular cambium activity. The limited secondary xylem development in inflorescence stems of herbaceous Arabidopsis plants was significantly reduced in ahl15 loss-of-function mutants, whereas constitutive or vascular meristem-specific AHL15 overexpression produced woody inflorescence stems. AHL15 was required for enhanced secondary xylem formation in the woody suppressor of overexpression of constans 1 (soc1) fruitfull (ful) double loss-of-function mutant. Moreover, we found that AHL15 induces vascular cambium activity downstream of the repressing SOC1 and FUL transcription factors, most likely similar to how it enhances lateral branching by promoting biosynthesis of the hormone cytokinin. Our results uncover a novel pathway driving cambium development, in which AHL15 expression levels act in parallel to and are dependent on the well-established TDIF-PXY-WOX pathway to differentiate between herbaceous and woody stem growth.
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Affiliation(s)
- Arezoo Rahimi
- Plant Developmental Genetics, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands
| | - Omid Karami
- Plant Developmental Genetics, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands.
| | - Angga Dwituti Lestari
- Plant Developmental Genetics, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands
| | - Tobias de Werk
- Plant Developmental Genetics, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands; Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Petra Amakorová
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany, The Czech Academy of Sciences, 78371 Olomouc, Czech Republic
| | - Dongbo Shi
- Department of Developmental Physiology, Centre for Organismal Studies (COS), Heidelberg University, 69120 Heidelberg, Germany
| | - Ondřej Novák
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany, The Czech Academy of Sciences, 78371 Olomouc, Czech Republic
| | - Thomas Greb
- Department of Developmental Physiology, Centre for Organismal Studies (COS), Heidelberg University, 69120 Heidelberg, Germany
| | - Remko Offringa
- Plant Developmental Genetics, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands.
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Inácio V, Santos R, Prazeres R, Graça J, Miguel CM, Morais-Cecílio L. Epigenetics at the crossroads of secondary growth regulation. Front Plant Sci 2022; 13:970342. [PMID: 35991449 PMCID: PMC9389228 DOI: 10.3389/fpls.2022.970342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/18/2022] [Indexed: 05/20/2023]
Abstract
The development of plant tissues and organs during post-embryonic growth occurs through the activity of both primary and secondary meristems. While primary meristems (root and shoot apical meristems) promote axial plant growth, secondary meristems (vascular and cork cambium or phellogen) promote radial thickening and plant axes strengthening. The vascular cambium forms the secondary xylem and phloem, whereas the cork cambium gives rise to the periderm that envelops stems and roots. Periderm takes on an increasingly important role in plant survival under climate change scenarios, but it is also a forest product with unique features, constituting the basis of a sustainable and profitable cork industry. There is established evidence that epigenetic mechanisms involving histone post-translational modifications, DNA methylation, and small RNAs play important roles in the activity of primary meristem cells, their maintenance, and differentiation of progeny cells. Here, we review the current knowledge on the epigenetic regulation of secondary meristems, particularly focusing on the phellogen activity. We also discuss the possible involvement of DNA methylation in the regulation of periderm contrasting phenotypes, given the potential impact of translating this knowledge into innovative breeding programs.
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Affiliation(s)
- Vera Inácio
- BioISI – Instituto de Biosistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
- *Correspondence: Vera Inácio,
| | - Raquel Santos
- BioISI – Instituto de Biosistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Rafael Prazeres
- BioISI – Instituto de Biosistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - José Graça
- Forest Research Centre (CEF), Institute of Agronomy, Universidade de Lisboa, Lisbon, Portugal
| | - Célia M. Miguel
- BioISI – Instituto de Biosistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Leonor Morais-Cecílio
- Linking Landscape, Environment, Agriculture and Food (LEAF), Institute of Agronomy, Associated Laboratory TERRA, Universidade de Lisboa, Lisbon, Portugal
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10
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Chiatante D, Montagnoli A, Trupiano D, Sferra G, Bryant J, Rost TL, Scippa GS. Meristematic Connectome: A Cellular Coordinator of Plant Responses to Environmental Signals? Cells 2021; 10:2544. [PMID: 34685524 DOI: 10.3390/cells10102544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 09/18/2021] [Accepted: 09/22/2021] [Indexed: 11/30/2022] Open
Abstract
Mechanical stress in tree roots induces the production of reaction wood (RW) and the formation of new branch roots, both functioning to avoid anchorage failure and limb damage. The vascular cambium (VC) is the factor responsible for the onset of these responses as shown by their occurrence when all primary tissues and the root tips are removed. The data presented confirm that the VC is able to evaluate both the direction and magnitude of the mechanical forces experienced before coordinating the most fitting responses along the root axis whenever and wherever these are necessary. The coordination of these responses requires intense crosstalk between meristematic cells of the VC which may be very distant from the place where the mechanical stress is first detected. Signaling could be facilitated through plasmodesmata between meristematic cells. The mechanism of RW production also seems to be well conserved in the stem and this fact suggests that the VC could behave as a single structure spread along the plant body axis as a means to control the relationship between the plant and its environment. The observation that there are numerous morphological and functional similarities between different meristems and that some important regulatory mechanisms of meristem activity, such as homeostasis, are common to several meristems, supports the hypothesis that not only the VC but all apical, primary and secondary meristems present in the plant body behave as a single interconnected structure. We propose to name this structure “meristematic connectome” given the possibility that the sequence of meristems from root apex to shoot apex could represent a pluricellular network that facilitates long-distance signaling in the plant body. The possibility that the “meristematic connectome” could act as a single structure active in adjusting the plant body to its surrounding environment throughout the life of a plant is now proposed.
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11
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Zheng S, He J, Lin Z, Zhu Y, Sun J, Li L. Two MADS-box genes regulate vascular cambium activity and secondary growth by modulating auxin homeostasis in Populus. Plant Commun 2021; 2:100134. [PMID: 34746756 PMCID: PMC8553971 DOI: 10.1016/j.xplc.2020.100134] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 11/02/2020] [Accepted: 11/19/2020] [Indexed: 05/20/2023]
Abstract
In trees, stem secondary growth depends on vascular cambium proliferation activity and subsequent cell differentiation, in which an auxin concentration gradient across the cambium area plays a crucial role in regulating the process. However, the underlying molecular mechanism for the establishment of auxin concentration is not fully understood. In this study, we identified two function-unknown MADS-box genes, VCM1 and VCM2, which are expressed specifically in the vascular cambium and modulate the subcellular homeostasis of auxin. Simultaneous knockdown of both VCM1 and VCM2 enhanced vascular cambium proliferation activity and subsequent xylem differentiation. Overexpression of VCM1 suppressed vascular cambium activity and wood formation by regulating PIN5 expression, which tuned the soluble auxin concentration in the vascular cambium area. This study reveals the role of VCM1 and VCM2 in regulating the proliferation activity of the vascular cambium and secondary growth by modulating the subcellular auxin homeostasis in Populus.
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Affiliation(s)
- Shuai Zheng
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Jiajia He
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zengshun Lin
- Hunan Agricultural University, Hunan 4101287, China
| | | | - Jiayan Sun
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Laigeng Li
- National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
- Corresponding author
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12
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Wang D, Chen Y, Li W, Li Q, Lu M, Zhou G, Chai G. Vascular Cambium: The Source of Wood Formation. Front Plant Sci 2021; 12:700928. [PMID: 34484265 PMCID: PMC8416278 DOI: 10.3389/fpls.2021.700928] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/27/2021] [Indexed: 05/29/2023]
Abstract
Wood is the most abundant biomass produced by land plants and is mainly used for timber, pulping, and paper making. Wood (secondary xylem) is derived from vascular cambium, and its formation encompasses a series of developmental processes. Extensive studies in Arabidopsis and trees demonstrate that the initiation of vascular stem cells and the proliferation and differentiation of the cambial derivative cells require a coordination of multiple signals, including hormones and peptides. In this mini review, we described the recent discoveries on the regulation of the three developmental processes by several signals, such as auxin, cytokinins, brassinosteroids, gibberellins, ethylene, TDIF peptide, and their cross talk in Arabidopsis and Populus. There exists a similar but more complex regulatory network orchestrating vascular cambium development in Populus than that in Arabidopsis. We end up with a look at the future research prospects of vascular cambium in perennial woody plants, including interfascicular cambium development and vascular stem cell regulation.
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Affiliation(s)
- Dian Wang
- College of Agronomy, Qingdao Agricultural University, Qingdao, China
| | - Yan Chen
- College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao, China
| | - Wei Li
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China
| | - Quanzi Li
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
| | - Mengzhu Lu
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Gongke Zhou
- College of Resources and Environment, Qingdao Agricultural University, Qingdao, China
| | - Guohua Chai
- College of Resources and Environment, Qingdao Agricultural University, Qingdao, China
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13
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Miodek A, Gizińska A, Włoch W, Kojs P. What do we know about growth of vessel elements of secondary xylem in woody plants? Biol Rev Camb Philos Soc 2021; 96:2911-2924. [PMID: 34374202 PMCID: PMC9291787 DOI: 10.1111/brv.12785] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/19/2021] [Accepted: 07/29/2021] [Indexed: 12/23/2022]
Abstract
Despite extensive knowledge about vessel element growth and the determination of the axial course of vessels, these processes are still not fully understood. They are usually explained as resulting primarily from hormonal regulation in stems. This review focuses on an increasingly discussed aspect - mechanical conditions in the vascular cambium. Mechanical conditions in cambial tissue are important for the growth of vessel elements, as well as other cambial derivatives. In relation to the type of stress acting on cambial cells (compressive versus tensile stress) we: (i) discuss the shape of the enlarging vessel elements observed in anatomical sections; (ii) present hypotheses regarding the location of intrusive growth of vessel elements and cambial initials; (iii) explain the relationship between the growth of vessel elements and fibres; and (iv) consider the effect of mechanical stress in determining the course of a vessel. We also highlight the relationship between mechanical stress and transport of the most extensively studied plant hormone - auxin. We conclude that the integration of a biomechanical factor with the commonly acknowledged hormonal regulation could significantly enhance the analysis of the formation of vessel elements as well as entire vessels, which transport water and minerals in numerous plant species.
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Affiliation(s)
- Adam Miodek
- Polish Academy of Sciences Botanical Garden - Centre for Biological Diversity Conservation in Powsin, Prawdziwka 2, 02-973, Warsaw, Poland.,Institute of Biology, University of Opole, Oleska 22, 45-052, Opole, Poland
| | - Aldona Gizińska
- Polish Academy of Sciences Botanical Garden - Centre for Biological Diversity Conservation in Powsin, Prawdziwka 2, 02-973, Warsaw, Poland.,Institute of Biology, University of Opole, Oleska 22, 45-052, Opole, Poland
| | - Wiesław Włoch
- Polish Academy of Sciences Botanical Garden - Centre for Biological Diversity Conservation in Powsin, Prawdziwka 2, 02-973, Warsaw, Poland
| | - Paweł Kojs
- Polish Academy of Sciences Botanical Garden - Centre for Biological Diversity Conservation in Powsin, Prawdziwka 2, 02-973, Warsaw, Poland
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14
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Shen D, Holmer R, Kulikova O, Mannapperuma C, Street NR, Yan Z, van der Maden T, Bu F, Zhang Y, Geurts R, Magne K. The BOP-type co-transcriptional regulator NODULE ROOT1 promotes stem secondary growth of the tropical Cannabaceae tree Parasponia andersonii. Plant J 2021; 106:1366-1386. [PMID: 33735477 PMCID: PMC9543857 DOI: 10.1111/tpj.15242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 03/16/2021] [Indexed: 05/13/2023]
Abstract
Tree stems undergo a massive secondary growth in which secondary xylem and phloem tissues arise from the vascular cambium. Vascular cambium activity is driven by endogenous developmental signalling cues and environmental stimuli. Current knowledge regarding the genetic regulation of cambium activity and secondary growth is still far from complete. The tropical Cannabaceae tree Parasponia andersonii is a non-legume research model of nitrogen-fixing root nodulation. Parasponia andersonii can be transformed efficiently, making it amenable for CRISPR-Cas9-mediated reverse genetics. We considered whether P. andersonii also could be used as a complementary research system to investigate tree-related traits, including secondary growth. We established a developmental map of stem secondary growth in P. andersonii plantlets. Subsequently, we showed that the expression of the co-transcriptional regulator PanNODULE ROOT1 (PanNOOT1) is essential for controlling this process. PanNOOT1 is orthologous to Arabidopsis thaliana BLADE-ON-PETIOLE1 (AtBOP1) and AtBOP2, which are involved in the meristem-to-organ-boundary maintenance. Moreover, in species forming nitrogen-fixing root nodules, NOOT1 is known to function as a key nodule identity gene. Parasponia andersonii CRISPR-Cas9 loss-of-function Pannoot1 mutants are altered in the development of the xylem and phloem tissues without apparent disturbance of the cambium organization and size. Transcriptomic analysis showed that the expression of key secondary growth-related genes is significantly down-regulated in Pannoot1 mutants. This allows us to conclude that PanNOOT1 positively contributes to the regulation of stem secondary growth. Our work also demonstrates that P. andersonii can serve as a tree research system.
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Affiliation(s)
- Defeng Shen
- Laboratory of Molecular BiologyDepartment of Plant SciencesWageningen University & ResearchWageningen6708PBThe Netherlands
- Present address:
Department of Plant Microbe InteractionsMax Planck Institute for Plant Breeding ResearchCologne50829Germany
| | - Rens Holmer
- Laboratory of Molecular BiologyDepartment of Plant SciencesWageningen University & ResearchWageningen6708PBThe Netherlands
| | - Olga Kulikova
- Laboratory of Molecular BiologyDepartment of Plant SciencesWageningen University & ResearchWageningen6708PBThe Netherlands
| | - Chanaka Mannapperuma
- Department of Plant PhysiologyUmeå Plant Science CentreUmeå UniversityUmeå907 36Sweden
| | - Nathaniel R. Street
- Department of Plant PhysiologyUmeå Plant Science CentreUmeå UniversityUmeå907 36Sweden
| | - Zhichun Yan
- Laboratory of Molecular BiologyDepartment of Plant SciencesWageningen University & ResearchWageningen6708PBThe Netherlands
| | - Thomas van der Maden
- Laboratory of Molecular BiologyDepartment of Plant SciencesWageningen University & ResearchWageningen6708PBThe Netherlands
| | - Fengjiao Bu
- Laboratory of Molecular BiologyDepartment of Plant SciencesWageningen University & ResearchWageningen6708PBThe Netherlands
| | - Yuanyuan Zhang
- Laboratory of Plant PhysiologyDepartment of Plant SciencesWageningen University & ResearchWageningen6708 PBThe Netherlands
- Present address:
State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresources, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant GermplasmCollege of Forestry and Landscape ArchitectureSouth China Agricultural UniversityGuangzhou510642China
| | - Rene Geurts
- Laboratory of Molecular BiologyDepartment of Plant SciencesWageningen University & ResearchWageningen6708PBThe Netherlands
| | - Kévin Magne
- Laboratory of Molecular BiologyDepartment of Plant SciencesWageningen University & ResearchWageningen6708PBThe Netherlands
- Present address:
Institute of Plant Sciences Paris‐Saclay (IPS2)Université Paris‐SaclayCNRSINRAEUniv EvryOrsay91405France
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15
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Lee J, Kim H, Park SG, Hwang H, Yoo SI, Bae W, Kim E, Kim J, Lee HY, Heo TY, Kang KK, Lee Y, Hong CP, Cho H, Ryu H. Brassinosteroid-BZR1/2-WAT1 module determines the high level of auxin signalling in vascular cambium during wood formation. New Phytol 2021; 230:1503-1516. [PMID: 33570747 DOI: 10.1111/nph.17265] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 02/03/2021] [Indexed: 06/12/2023]
Abstract
The tight regulation of local auxin homeostasis and signalling maxima in xylem precursor cells specifies the organising activity of the vascular cambium and consequently promotes xylem differentiation and wood formation. However, the molecular mechanisms underlying the local auxin signalling maxima in the vascular cambium are largely unknown. Here, we reveal that brassinosteroid (BR)-activated WALLS ARE THIN1 (WAT1) facilitates wood formation by enhancing local auxin signalling in the vascular cambium in Solanum lycopersicum. Growth defects and low auxin signalling readouts in the BR-deficient tomato cultivar, Micro-Tom, were associated with a novel recessive allele, Slwat1-copi, created by the insertion of a retrotransposon in the last exon of the SlWAT1 locus. Molecular and genetic studies by generating the gain-of-function and loss-of-function tomato mutants revealed that SlWAT1 is a critical regulator for fine tuning local auxin homeostasis and signalling outputs in vascular cambium to facilitate secondary growth. Finally, we discovered that BR-regulated SlBZR1/2 directly activated downstream auxin responses by SlWAT1 upregulation in xylem precursor cells to facilitate xylem differentiation and subsequent wood formation. Our data suggest that the BR-SlBZR1/2-WAT1 signalling network contributes to the high level of auxin signalling in the vascular cambium for secondary growth.
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Affiliation(s)
- Jinsu Lee
- Department of Biology, Chungbuk National University, Cheongju, 28644, Korea
- School of Biological Sciences, Seoul National University, Seoul, 08826, Korea
| | - Hyemin Kim
- Department of Biology, Chungbuk National University, Cheongju, 28644, Korea
| | | | - Hyeona Hwang
- Department of Biology, Chungbuk National University, Cheongju, 28644, Korea
| | | | - Wonsil Bae
- Department of Biology, Chungbuk National University, Cheongju, 28644, Korea
| | - Eunhui Kim
- Department of Biology, Chungbuk National University, Cheongju, 28644, Korea
| | - Jaehoon Kim
- Department of Information and Statistics, Chungbuk National University, Cheongju, 28644, Korea
| | - Hwa-Yong Lee
- Department of Forest Science, Chungbuk National University, Cheongju, 28644, Korea
| | - Tae-Young Heo
- Department of Information and Statistics, Chungbuk National University, Cheongju, 28644, Korea
| | - Kwon Kyoo Kang
- Department of Horticulture, Hankyong National University, Ansung, 17579, Korea
| | - Yuree Lee
- School of Biological Sciences, Seoul National University, Seoul, 08826, Korea
| | | | - Hyunwoo Cho
- Department of Industrial Plant Science and Technology, Chungbuk National University, Cheongju, 28644, Korea
| | - Hojin Ryu
- Department of Biology, Chungbuk National University, Cheongju, 28644, Korea
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16
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Hu H, Guo Z, Yang J, Cui J, Zhang Y, Xu J. Transcriptome and microRNA Sequencing Identified miRNAs and Target Genes in Different Developmental Stages of the Vascular Cambium in Cryptomeria fortunei Hooibrenk. Front Plant Sci 2021; 12:751771. [PMID: 34868137 PMCID: PMC8638621 DOI: 10.3389/fpls.2021.751771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/28/2021] [Indexed: 05/15/2023]
Abstract
Cryptomeria fortunei Hooibrenk is an important fast-growing coniferous timber species that is widely used in landscaping. Recently, research on timber quality has gained substantial attention in the field of tree breeding. Wood is the secondary xylem formed by the continuous inward division and differentiation of the vascular cambium; therefore, the development of the vascular cambium is particularly important for wood quality. In this study, we analyzed the transcriptomes of the cambial zone in C. fortunei during different developmental stages using Illumina HiSeq sequencing, focusing on general transcriptome and microRNA (miRNA) data. We performed functional annotation of the differentially expressed genes (DEGs) in the different stages identified by transcriptome sequencing and generated 15 miRNA libraries yielding 4.73 Gb of clean reads. The most common length of the filtered miRNAs was 21nt, accounting for 33.1% of the total filtered reads. We annotated a total of 32 known miRNA families. Some miRNAs played roles in hormone signal transduction (miR159, miR160, and miR166), growth and development (miR166 and miR396), and the coercion response (miR394 and miR395), and degradome sequencing showed potential cleavage sites between miRNAs and target genes. Differential expression of miRNAs and target genes and functional validation of the obtained transcriptome and miRNA data provide a theoretical basis for further elucidating the molecular mechanisms of cellular growth and differentiation, as well as wood formation in the vascular cambium, which will help improve the wood quality of C. fortunei.
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Affiliation(s)
- Hailiang Hu
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Zhenhao Guo
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
- Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Horticulture, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Junjie Yang
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Jiebing Cui
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Yingting Zhang
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Jin Xu
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- College of Forestry, Nanjing Forestry University, Nanjing, China
- *Correspondence: Jin Xu,
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17
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Xiao W, Molina D, Wunderling A, Ripper D, Vermeer JEM, Ragni L. Pluripotent Pericycle Cells Trigger Different Growth Outputs by Integrating Developmental Cues into Distinct Regulatory Modules. Curr Biol 2020; 30:4384-4398.e5. [PMID: 32916110 DOI: 10.1016/j.cub.2020.08.053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/22/2020] [Accepted: 08/14/2020] [Indexed: 01/24/2023]
Abstract
During post-embryonic development, the pericycle specifies the stem cells that give rise to both lateral roots (LRs) and the periderm, a suberized barrier that protects the plant against biotic and abiotic stresses. Comparable auxin-mediated signaling hubs regulate meristem establishment in many developmental contexts; however, it is unknown how specific outputs are achieved. Using the Arabidopsis root as a model, we show that while LR formation is the main auxin-induced program after de-etiolation, plants with age become competent to form a periderm in response to auxin. The establishment of the vascular cambium acts as the developmental switch required to trigger auxin-mediated periderm initiation. Moreover, distinct auxin signaling components and targets control LR versus periderm formation. Among the periderm-specific-promoting transcription factors, WUSCHEL-RELATED HOMEOBOX 4 (WOX4) and KNAT1/BREVIPEDICELLUS (BP) stand out as their specific overexpression in the periderm results in an increased number of periderm layers, a trait of agronomical importance in breeding programs targeting stress tolerance. These findings reveal that specificity in pericycle stem cell fate is achieved by the integration of developmental cues into distinct regulatory modules.
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Affiliation(s)
- Wei Xiao
- ZMBP-Center for Plant Molecular Biology, University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany
| | - David Molina
- ZMBP-Center for Plant Molecular Biology, University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany
| | - Anna Wunderling
- ZMBP-Center for Plant Molecular Biology, University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany
| | - Dagmar Ripper
- ZMBP-Center for Plant Molecular Biology, University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany
| | - Joop E M Vermeer
- Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Laura Ragni
- ZMBP-Center for Plant Molecular Biology, University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
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18
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Affiliation(s)
- Melis Kucukoglu
- Institute of Biotechnology, Helsinki Institute of Life Science (HILIFE), University of Helsinki, Helsinki, 00014, Finland
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19
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Povilus RA, DaCosta JM, Grassa C, Satyaki PRV, Moeglein M, Jaenisch J, Xi Z, Mathews S, Gehring M, Davis CC, Friedman WE. Water lily ( Nymphaea thermarum) genome reveals variable genomic signatures of ancient vascular cambium losses. Proc Natl Acad Sci U S A 2020; 117:8649-56. [PMID: 32234787 DOI: 10.1073/pnas.1922873117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
For more than 225 million y, all seed plants were woody trees, shrubs, or vines. Shortly after the origin of angiosperms ∼140 million y ago (MYA), the Nymphaeales (water lilies) became one of the first lineages to deviate from their ancestral, woody habit by losing the vascular cambium, the meristematic population of cells that produces secondary xylem (wood) and phloem. Many of the genes and gene families that regulate differentiation of secondary tissues also regulate the differentiation of primary xylem and phloem, which are produced by apical meristems and retained in nearly all seed plants. Here, we sequenced and assembled a draft genome of the water lily Nymphaea thermarum, an emerging system for the study of early flowering plant evolution, and compared it to genomes from other cambium-bearing and cambium-less lineages (e.g., monocots and Nelumbo). This revealed lineage-specific patterns of gene loss and divergence. Nymphaea is characterized by a significant contraction of the HD-ZIP III transcription factors, specifically loss of REVOLUTA, which influences cambial activity in other angiosperms. We also found the Nymphaea and monocot copies of cambium-associated CLE signaling peptides display unique substitutions at otherwise highly conserved amino acids. Nelumbo displays no obvious divergence in cambium-associated genes. The divergent genomic signatures of convergent loss of vascular cambium reveals that even pleiotropic genes can exhibit unique divergence patterns in association with independent events of trait loss. Our results shed light on the evolution of herbaceousness-one of the key biological innovations associated with the earliest phases of angiosperm evolution.
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20
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Ding G, Lei GJ, Yamaji N, Yokosho K, Mitani-Ueno N, Huang S, Ma JF. Vascular Cambium-Localized AtSPDT Mediates Xylem-to-Phloem Transfer of Phosphorus for Its Preferential Distribution in Arabidopsis. Mol Plant 2020; 13:99-111. [PMID: 31610248 DOI: 10.1016/j.molp.2019.10.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 09/18/2019] [Accepted: 09/25/2019] [Indexed: 06/10/2023]
Abstract
During plant growth and development mineral elements are preferentially delivered to different organs and tissues to meet the differential demand. It has been shown that the preferential distribution of mineral nutrients in gramineous plants is mediated by node-based transporters, but the mechanisms of preferential distribution in dicots are poorly understood. Here, we report a distinct mechanism for the preferential distribution of phosphorus (P) in Arabidopsis plants, revealed by detailed functional analysis of AtSPDT/AtSULTR3;4 (SULTR-like P Distribution Transporter), a homolog of rice OsSPDT. Like OsSPDT, AtSPDT is localized at the plasma membrane and showed proton-dependent transport activity for P. Interestingly, we found that AtSPDT is mainly expressed in the rosette basal region and leaf petiole, and its expression is up-regulated by P deficiency. Tissue-specific analysis showed that AtSPDT is mainly located in the vascular cambium of different organs, as well as in the parenchyma tissues of both xylem and phloem regions. Knockout of AtSPDT inhibited the growth of new leaves under low P due to decreased P distribution to those organs. The seed yields of the wild-type and atspdt mutant plants are similar, but the seeds of mutant plants contain - less P. These results indicate that AtSPDT localized in the vascular cambium is involved in preferential distribution of P to the developing tissues, through xylem-to-phloem transfer mainly at the rosette basal region and leaf petiole.
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Affiliation(s)
- Guangda Ding
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Japan; College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Gui Jie Lei
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Japan
| | - Naoki Yamaji
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Japan
| | - Kengo Yokosho
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Japan
| | - Namiki Mitani-Ueno
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Japan
| | - Sheng Huang
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Japan
| | - Jian Feng Ma
- Institute of Plant Science and Resources, Okayama University, Chuo 2-20-1, Kurashiki, Japan.
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21
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Chery JG, Pace MR, Acevedo-Rodríguez P, Specht CD, Rothfels CJ. Modifications during Early Plant Development Promote the Evolution of Nature's Most Complex Woods. Curr Biol 2019; 30:237-244.e2. [PMID: 31839457 DOI: 10.1016/j.cub.2019.11.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 10/31/2019] [Accepted: 11/01/2019] [Indexed: 12/27/2022]
Abstract
Secondary growth is the developmental process by which woody plants grow radially. The most complex presentations of secondary growth are found in lianas (woody vines) as a result of the unique demand to maintain stems that can twist without breaking. The complex woody forms in lianas arise as non-circular stem outlines, aberrant tissue configurations, and/or shifts in the relative abundance of secondary tissues. Previous studies demonstrate that abnormal activity of the vascular cambium leads to variant secondary growth; however, the developmental and evolutionary basis for this shift is still largely unknown. Here, we adopt an integrative approach, leveraging techniques from historically distinct disciplines-developmental anatomy and phylogenetic comparative methods-to elucidate the evolution of development of the complex woody forms in a large lineage of tropical lianas, Paullinia L. (Sapindaceae). We find that all forms of variant secondary growth trace back to the same modification during early stem development, which results in young plants with lobed stem outlines and a discontinuous distribution of vascular bundles. By placing development in a phylogenetic context, we further show that the lobed primary plant bauplan is the evolutionary precursor to all complex woody forms. We find evidence for three evolutionary mechanisms that generate phenotypic novelty: exaptation and co-opting of the ancestral bauplan, the quasi-independence of the interfascicular and fascicular cambia, and the inclusion of additional developmental stages to the end of the ancestral ontogeny. Our study demonstrates the utility of integrating developmental data within a phylogenetic framework to investigate the evolution of complex traits.
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Affiliation(s)
- Joyce G Chery
- University Herbarium and Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
| | - Marcelo R Pace
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de Ciudad Universitaria, Mexico City 04510, Mexico
| | - Pedro Acevedo-Rodríguez
- Department of Botany, Smithsonian National Museum of Natural History, West Loading Dock, 10(th) and Constitution Avenue NW, Washington, DC 20560, USA
| | - Chelsea D Specht
- School of Integrative Plant Sciences and L.H. Bailey Hortorium, Cornell University, Ithaca, NY 14853, USA
| | - Carl J Rothfels
- University Herbarium and Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
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22
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Kim MH, Cho JS, Jeon HW, Sangsawang K, Shim D, Choi YI, Park EJ, Lee H, Ko JH. Wood Transcriptome Profiling Identifies Critical Pathway Genes of Secondary Wall Biosynthesis and Novel Regulators for Vascular Cambium Development in Populus. Genes (Basel) 2019; 10:E690. [PMID: 31500311 PMCID: PMC6770981 DOI: 10.3390/genes10090690] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 09/02/2019] [Accepted: 09/04/2019] [Indexed: 12/23/2022] Open
Abstract
Wood, the most abundant biomass on Earth, is composed of secondary xylem differentiated from vascular cambium. However, the underlying molecular mechanisms of wood formation remain largely unclear. To gain insight into wood formation, we performed a series of wood-forming tissue-specific transcriptome analyses from a hybrid poplar (Populus alba × P. glandulosa, clone BH) using RNA-seq. Together with shoot apex and leaf tissue, cambium and xylem tissues were isolated from vertical stem segments representing a gradient of secondary growth developmental stages (i.e., immature, intermediate, and mature stem). In a comparative transcriptome analysis of the 'developing xylem' and 'leaf' tissue, we could identify critical players catalyzing each biosynthetic step of secondary wall components (e.g., cellulose, xylan, and lignin). Several candidate genes involved in the initiation of vascular cambium formation were found via a co-expression network analysis using abundantly expressed genes in the 'intermediate stem-derived cambium' tissue. We found that transgenic Arabidopsis plants overexpressing the PtrHAM4-1, a GRAS family transcription factor, resulted in a significant increase of vascular cambium development. This phenotype was successfully reproduced in the transgenic poplars overexpressing the PtrHAM4-1. Taken together, our results may serve as a springboard for further research to unravel the molecular mechanism of wood formation, one of the most important biological processes on this planet.
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Affiliation(s)
- Min-Ha Kim
- Department of Plant & Environmental New Resources, Kyung Hee University, Yongin 446-701, Korea.
| | - Jin-Seong Cho
- Department of Plant & Environmental New Resources, Kyung Hee University, Yongin 446-701, Korea.
| | - Hyung-Woo Jeon
- Department of Plant & Environmental New Resources, Kyung Hee University, Yongin 446-701, Korea.
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, NSW 2006, Australia.
| | - Kanidta Sangsawang
- Department of Plant & Environmental New Resources, Kyung Hee University, Yongin 446-701, Korea.
| | - Donghwan Shim
- Korea Forest Research Institute, Suwon 16631, Korea.
| | - Young-Im Choi
- Korea Forest Research Institute, Suwon 16631, Korea.
| | - Eung-Jun Park
- Korea Forest Research Institute, Suwon 16631, Korea.
| | - Hyoshin Lee
- Korea Forest Research Institute, Suwon 16631, Korea.
| | - Jae-Heung Ko
- Department of Plant & Environmental New Resources, Kyung Hee University, Yongin 446-701, Korea.
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Ma Q, Bu D, Zhang J, Wu Y, Pei D. The Transcriptome Landscape of Walnut Interspecies Hybrid ( Juglans hindsii × Juglans regia) and Regulation of Cambial Activity in Relation to Grafting. Front Genet 2019; 10:577. [PMID: 31293615 PMCID: PMC6598599 DOI: 10.3389/fgene.2019.00577] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/03/2019] [Indexed: 12/18/2022] Open
Abstract
Walnuts (Juglans, Juglandaceae) are known throughout the world as economically important trees that provide fat, protein, vitamins, and minerals as a food source, and produce high-quality timber. We have amended the purpose section to say "However," the omics resources are limited, which hampered the elucidation of molecular mechanisms resulting in their economically important traits (such as yield, fertility alternation, oil synthesis, and wood formation). To enrich the omics database of walnut, there is great need for analyses of its genomic and transcriptomic characteristics. In this study, we reported for the first time of the transcriptome landscape of six important organs or tissues in walnut interspecies hybrid using next-generation sequencing technology. Over 338 million clean reads were obtained. This yielded 74,072 unigenes with an average length of 782.71 bp. To develop an understanding of gene functions and regulatory pathways, 66,355 of the unigenes were identified as homologs of annotated genes and classified into three general categories with 61 functional subcategories. 2,288 out of 2,549 unmapped unigenes had at least one BLAST hit against the public databases. A total of 1,237 transcription factor-encoding genes (TFs) and 2,297 tissue-specific unigenes were identified. Interestingly, in the new shoot between an adult seedling and a grafted tree, the expression of 9,494 unigenes were significantly different, among which 4,388 were up-regulated and 5,106 were down-regulated. Of these, 195, 177, 232, 75, 114, and 68 unigenes were related to transcription factors, cell wall, defense response, transport, plant hormone biosynthesis, and other cambial activity-related functions, respectively. The obtained sequences and putative functional data constitute a resource for future functional analyses in walnut and other woody plants. These findings will be useful in further studies addressing the molecular mechanisms underlying grafting-related cambial activity.
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Affiliation(s)
- Qingguo Ma
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Dechao Bu
- Key Laboratory of Intelligent Information Processing, Advanced Computing Research Laboratory, Institute of Computing Technology, Chinese Academy of Sciences, Beijing, China
| | - Junpei Zhang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
| | - Yang Wu
- Key Laboratory of Intelligent Information Processing, Advanced Computing Research Laboratory, Institute of Computing Technology, Chinese Academy of Sciences, Beijing, China
| | - Dong Pei
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
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24
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Abstract
Woodiness (secondary xylem derived from vascular cambium) has been gained and lost multiple times in the angiosperms, but has been lost ancestrally in all monocots. Here, we investigate the conservation of genes involved in xylogenesis in fully sequenced angiosperm genomes, hypothesizing that monocots have lost some essential orthologs involved in this process. We analyzed the conservation of genes preferentially expressed in the developing secondary xylem of two eudicot trees in the sequenced genomes of 26 eudicot and seven monocot species, and the early diverging angiosperm Amborella trichopoda. We also reconstructed a regulatory model of early vascular cambial cell identity and differentiation and investigated the conservation of orthologs across the angiosperms. Additionally, we analyzed the genome of the aquatic seagrass Zostera marina for additional losses of genes otherwise essential to, especially, secondary cell wall formation. Despite almost complete conservation of orthology within the early cambial differentiation gene network, we show a clear pattern of loss of genes preferentially expressed in secondary xylem in the monocots that are highly conserved across eudicot species. Our study provides candidate genes that may have led to the loss of vascular cambium in the monocots, and, by comparing terrestrial angiosperms to an aquatic monocot, highlights genes essential to vasculature on land.
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Affiliation(s)
- Danielle Roodt
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, South Africa
- Genomics Research Institute, University of Pretoria, South Africa
| | - Zhen Li
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Belgium
- VIB Center for Plant Systems Biology, VIB, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Belgium
| | - Yves Van de Peer
- Genomics Research Institute, University of Pretoria, South Africa
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Belgium
- VIB Center for Plant Systems Biology, VIB, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Belgium
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, South Africa
| | - Eshchar Mizrachi
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, South Africa
- Genomics Research Institute, University of Pretoria, South Africa
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25
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Tomescu AMF, Groover AT. Mosaic modularity: an updated perspective and research agenda for the evolution of vascular cambial growth. New Phytol 2019; 222:1719-1735. [PMID: 30552764 DOI: 10.1111/nph.15640] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 11/28/2018] [Indexed: 06/09/2023]
Abstract
Secondary growth from a vascular cambium, present today only in seed plants and isoetalean lycophytes, has a 400-million-yr evolutionary history that involves considerably broader taxonomic diversity, most of it hidden in the fossil record. Approaching vascular cambial growth as a complex developmental process, we review data from living plants and fossils that reveal diverse modes of secondary growth. These are consistent with a modular nature of secondary growth, when considered as a tracheophyte-wide structural feature. This modular perspective identifies putative constituent developmental modules of cambial growth, for which we review developmental anatomy and regulation. Based on these data, we propose a hypothesis that explains the sources of diversity of secondary growth, considered across the entire tracheophyte clade, and opens up new avenues for exploring the origin of secondary growth. In this hypothesis, various modes of secondary growth reflect a mosaic pattern of expression of different developmental-regulatory modules among different lineages. We outline an approach that queries three information systems (living seed plants, living seed-free plants, and fossils) and integrates data on developmental regulation, anatomy, gene evolution and phylogeny to test the mosaic modularity hypothesis and its implications, and to inform efforts aimed at understanding the evolution of secondary growth.
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Affiliation(s)
- Alexandru M F Tomescu
- Department of Biological Sciences, Humboldt State University, Arcata, CA, 95521, USA
| | - Andrew T Groover
- Pacific Southwest Research Station, USDA Forest Service, Davis, CA, 95618, USA
- Department of Plant Biology, University of California, Davis, CA, 95616, USA
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26
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Rodriguez-Zaccaro FD, Valdovinos-Ayala J, Percolla MI, Venturas MD, Pratt RB, Jacobsen AL. Wood structure and function change with maturity: Age of the vascular cambium is associated with xylem changes in current-year growth. Plant Cell Environ 2019; 42:1816-1831. [PMID: 30707440 DOI: 10.1111/pce.13528] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/27/2019] [Accepted: 01/28/2019] [Indexed: 06/09/2023]
Abstract
Xylem vessel structure changes as trees grow and mature. Age- and development-related changes in xylem structure are likely related to changes in hydraulic function. We examined whether hydraulic function, including hydraulic conductivity and vulnerability to water-stress-induced xylem embolism, changed over the course of cambial development in the stems of 17 tree species. We compared current-year growth of young (1-4 years), intermediate (2-7 years), and older (3-10 years) stems occurring in series along branches. Diffuse and ring porous species were examined, but nearly all species produced only diffuse porous xylem in the distal branches that were examined irrespective of their mature xylem porosity type. Vessel diameter and length increased with cambial age. Xylem became both more conductive and more cavitation resistant with cambial age. Ring porous species had longer and wider vessels and xylem that had higher conductivity and was more vulnerable to cavitation; however, these differences between porosity types were not present in young stem samples. Understanding plant hydraulic function and architecture requires the sampling of multiple-aged tissues because plants may vary considerably in their xylem structural and functional traits throughout the plant body, even over relatively short distances and closely aged tissues.
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Affiliation(s)
| | | | - Marta I Percolla
- Department of Biology, California State University, Bakersfield, Bakersfield, California
| | - Martin D Venturas
- Department of Biology, California State University, Bakersfield, Bakersfield, California
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid (UPM), Madrid, Spain
| | - R Brandon Pratt
- Department of Biology, California State University, Bakersfield, Bakersfield, California
| | - Anna L Jacobsen
- Department of Biology, California State University, Bakersfield, Bakersfield, California
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27
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Abstract
Stem cell populations in meristematic tissues at distinct locations in the plant body provide the potency of continuous plant growth. Primary meristems, at the apices of the plant body, contribute mainly to the elongation of the main plant axes, whereas secondary meristems in lateral positions are responsible for the thickening of these axes. The stem cells of the vascular cambium-a secondary lateral meristem-produce the secondary phloem (bast) and secondary xylem (wood). The sites of primary and secondary growth are spatially separated, and mobile signals are expected to coordinate growth rates between apical and lateral stem cell populations. Although the underlying mechanisms have not yet been uncovered, it seems likely that hormones, peptides, and mechanical cues orchestrate primary and secondary growth. In this review, we highlight the current knowledge and recent discoveries of how cambial stem cell activity is regulated, with a focus on mobile signals and the response of cambial activity to environmental and stress factors.
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Affiliation(s)
- Urs Fischer
- KWS SAAT SE, 37555 Einbeck, Germany
- Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden;
| | - Melis Kucukoglu
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, 00014 Helsinki, Finland
| | - Ykä Helariutta
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, 00014 Helsinki, Finland
- Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, United Kingdom
| | - Rishikesh P Bhalerao
- Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden;
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
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28
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Qaderi MM, Martel AB, Dixon SL. Environmental Factors Influence Plant Vascular System and Water Regulation. Plants (Basel) 2019; 8:plants8030065. [PMID: 30875945 PMCID: PMC6473727 DOI: 10.3390/plants8030065] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 02/28/2019] [Accepted: 03/11/2019] [Indexed: 11/16/2022]
Abstract
Developmental initiation of plant vascular tissue, including xylem and phloem, from the vascular cambium depends on environmental factors, such as temperature and precipitation. Proper formation of vascular tissue is critical for the transpiration stream, along with photosynthesis as a whole. While effects of individual environmental factors on the transpiration stream are well studied, interactive effects of multiple stress factors are underrepresented. As expected, climate change will result in plants experiencing multiple co-occurring environmental stress factors, which require further studies. Also, the effects of the main climate change components (carbon dioxide, temperature, and drought) on vascular cambium are not well understood. This review aims at synthesizing current knowledge regarding the effects of the main climate change components on the initiation and differentiation of vascular cambium, the transpiration stream, and photosynthesis. We predict that combined environmental factors will result in increased diameter and density of xylem vessels or tracheids in the absence of water stress. However, drought may decrease the density of xylem vessels or tracheids. All interactive combinations are expected to increase vascular cell wall thickness, and therefore increase carbon allocation to these tissues. A comprehensive study of the effects of multiple environmental factors on plant vascular tissue and water regulation should help us understand plant responses to climate change.
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Affiliation(s)
- Mirwais M Qaderi
- Department of Biology, Mount Saint Vincent University, 166 Bedford Highway, Halifax, NS B3M 2J6, Canada.
- Department of Biology, Saint Mary's University, 923 Robie Street, Halifax, NS B3H 3C3, Canada.
| | - Ashley B Martel
- Department of Biology, Saint Mary's University, 923 Robie Street, Halifax, NS B3H 3C3, Canada.
| | - Sage L Dixon
- Department of Biology, Mount Saint Vincent University, 166 Bedford Highway, Halifax, NS B3M 2J6, Canada.
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29
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Savage JA. A temporal shift in resource allocation facilitates flowering before leaf out and spring vessel maturation in precocious species. Am J Bot 2019; 106:113-122. [PMID: 30629737 DOI: 10.1002/ajb2.1222] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 10/29/2018] [Indexed: 05/29/2023]
Abstract
PREMISE OF THE STUDY New growth in the spring requires resource mobilization in the vascular system at a time when xylem and phloem function are often reduced in seasonally cold climates. As a result, the timing of leaf out and/or flowering could depend on when the vascular system resumes normal function in the spring. This study investigated whether flowering time is influenced by vascular phenology in plants that flower precociously before they have leaves. METHODS Flower, leaf, and vascular phenology were monitored in pairs of precocious and non-precocious congeners. Differences in resource allocation were quantified by measuring bud dry mass and water content throughout the year, floral hydration was modelled, and a girdling treatment completed on branches in the field. KEY RESULTS Precocious flowering species invested more in floral buds the year before flowering than did their non-precocious congeners, thus mobilizing less water in the spring, which allowed flowering before new vessel maturation. CONCLUSIONS A shift in the timing of resource allocation in precocious flowering plants allowed them to flower before the production of mature vessels and minimized the significance of seasonal changes in vascular function to their flowering phenology. The low investment required to complete floral development in the spring when the plant vascular system is often compromised could explain why flowers can emerge before leaf out.
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Affiliation(s)
- Jessica A Savage
- Department of Biology, University of Minnesota, Duluth, MN, USA
- Arnold Arboretum, Harvard University, Boston, MA, USA
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30
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Chiatante D, Rost T, Bryant J, Scippa GS. Regulatory networks controlling the development of the root system and the formation of lateral roots: a comparative analysis of the roles of pericycle and vascular cambium. Ann Bot 2018; 122:697-710. [PMID: 29394314 PMCID: PMC6215048 DOI: 10.1093/aob/mcy003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 01/08/2018] [Indexed: 05/07/2023]
Abstract
Background The production of a new lateral root from parental root primary tissues has been investigated extensively, and the most important regulatory mechanisms are now well known. A first regulatory mechanism is based on the synthesis of small peptides which interact ectopically with membrane receptors to elicit a modulation of transcription factor target genes. A second mechanism involves a complex cross-talk between plant hormones. It is known that lateral roots are formed even in parental root portions characterized by the presence of secondary tissues, but there is not yet agreement about the putative tissue source providing the cells competent to become founder cells of a new root primordium. Scope We suggest models of possible regulatory mechanisms for inducing specific root vascular cambium (VC) stem cells to abandon their activity in the production of xylem and phloem elements and to start instead the construction of a new lateral root primordium. Considering the ontogenic nature of the VC, the models which we suggest are the result of a comparative review of mechanisms known to control the activity of stem cells in the root apical meristem, procambium and VC. Stem cells in the root meristems can inherit various competences to play different roles, and their fate could be decided in response to cross-talk between endogenous and exogenous signals. Conclusions We have found a high degree of relatedness among the regulatory mechanisms controlling the various root meristems. This fact suggests that competence to form new lateral roots can be inherited by some stem cells of the VC lineage. This kind of competence could be represented by a sensitivity of specific stem cells to factors such as those presented in our models.
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Affiliation(s)
- Donato Chiatante
- Dipartimento di Biotecnologie e Scienze della Vita, University of Insubria, Varese, Italy
| | - Thomas Rost
- Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA, USA
| | - John Bryant
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
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31
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Johnson D, Eckart P, Alsamadisi N, Noble H, Martin C, Spicer R. Polar auxin transport is implicated in vessel differentiation and spatial patterning during secondary growth in Populus. Am J Bot 2018; 105:186-196. [PMID: 29578291 DOI: 10.1002/ajb2.1035] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 01/24/2018] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY Dimensions and spatial distribution of vessels are critically important features of woody stems, allowing for adaptation to different environments through their effects on hydraulic efficiency and vulnerability to embolism. Although our understanding of vessel development is poor, basipetal transport of auxin through the cambial zone may play an important role. METHODS Stems of Populus tremula ×alba were treated with the auxin transport inhibitor N-1-naphthylphthalamic acid (NPA) in a longitudinal strip along the length of the lower stem. Vessel lumen diameter, circularity, and length; xylem growth; tension wood area; and hydraulic conductivity before and after a high pressure flush were determined on both NPA-treated and control plants. KEY RESULTS NPA-treated stems formed aberrant vessels that were short, small in diameter, highly clustered, and angular in cross section, whereas xylem formed on the untreated side of the stem contained typical vessels that were similar to those of controls. NPA-treated stems had reduced specific conductivity relative to controls, but this difference was eliminated by the high-pressure flush. The control treatment (lanolin + dimethyl sulfoxide) reduced xylem growth and increased tension wood formation, but never produced the aberrant vessel patterning seen in NPA-treated stems. CONCLUSIONS These results are consistent with a model of vessel development in which basipetal polar auxin transport through the xylem-side cambial derivatives is required for proper expansion and patterning of vessels and demonstrate that reduced auxin transport can produce stems with altered stem hydraulic properties.
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Affiliation(s)
- Dan Johnson
- Department of Botany, Connecticut College, New London, CT 06320, USA
| | - Phoebe Eckart
- Department of Botany, Connecticut College, New London, CT 06320, USA
| | - Noah Alsamadisi
- Department of Botany, Connecticut College, New London, CT 06320, USA
| | | | - Celia Martin
- Department of Biology, Connecticut College, New London, CT 06320, USA
| | - Rachel Spicer
- Department of Botany, Connecticut College, New London, CT 06320, USA
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32
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Kucukoglu M, Nilsson J, Zheng B, Chaabouni S, Nilsson O. WUSCHEL-RELATED HOMEOBOX4 (WOX4)-like genes regulate cambial cell division activity and secondary growth in Populus trees. New Phytol 2017; 215:642-657. [PMID: 28609015 DOI: 10.1111/nph.14631] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 04/23/2017] [Indexed: 05/12/2023]
Abstract
Plant secondary growth derives from the meristematic activity of the vascular cambium. In Arabidopsis thaliana, cell divisions in the cambium are regulated by the transcription factor WOX4, a key target of the CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION (ESR)-RELATED 41 (CLE41) signaling pathway. However, function of the WOX4-like genes in plants that are dependent on a much more prolific secondary growth, such as trees, remains unclear. Here, we investigate the role of WOX4 and CLE41 homologs for stem secondary growth in Populus trees. In Populus, PttWOX4 genes are specifically expressed in the cambial region during vegetative growth, but not after growth cessation and during dormancy, possibly involving a regulation by auxin. In PttWOX4a/b RNAi trees, primary growth was not affected whereas the width of the vascular cambium was severely reduced and secondary growth was greatly diminished. Our data show that in Populus trees, PttWOX4 genes control cell division activity in the vascular cambium, and hence growth in stem girth. This activity involves the positive regulation of PttWOX4a/b through PttCLE41-related genes. Finally, expression profiling suggests that the CLE41 signaling pathway is an evolutionarily conserved program for the regulation of vascular cambium activity between angiosperm and gymnosperm tree species.
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Affiliation(s)
- Melis Kucukoglu
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, SE-901 83, Sweden
| | - Jeanette Nilsson
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, SE-901 83, Sweden
| | - Bo Zheng
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
| | - Salma Chaabouni
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, SE-901 83, Sweden
| | - Ove Nilsson
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, SE-901 83, Sweden
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33
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Hacke UG, Spicer R, Schreiber SG, Plavcová L. An ecophysiological and developmental perspective on variation in vessel diameter. Plant Cell Environ 2017; 40:831-845. [PMID: 27304704 DOI: 10.1111/pce.12777] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 05/27/2016] [Accepted: 05/31/2016] [Indexed: 05/05/2023]
Abstract
Variation in xylem vessel diameter is one of the most important parameters when evaluating plant water relations. This review provides a synthesis of the ecophysiological implications of variation in lumen diameter together with a summary of our current understanding of vessel development and its endogenous regulation. We analyzed inter-specific variation of the mean hydraulic vessel diameter (Dv ) across biomes, intra-specific variation of Dv under natural and controlled conditions, and intra-plant variation. We found that the Dv measured in young branches tends to stay below 30 µm in regions experiencing winter frost, whereas it is highly variable in the tropical rainforest. Within a plant, the widest vessels are often found in the trunk and in large roots; smaller diameters have been reported for leaves and small lateral roots. Dv varies in response to environmental factors and is not only a function of plant size. Despite the wealth of data on vessel diameter variation, the regulation of diameter is poorly understood. Polar auxin transport through the vascular cambium is a key regulator linking foliar and xylem development. Limited evidence suggests that auxin transport is also a determinant of vessel diameter. The role of auxin in cell expansion and in establishing longitudinal continuity during secondary growth deserve further study.
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Affiliation(s)
- Uwe G Hacke
- University of Alberta, Department of Renewable Resources, Edmonton, AB T6G 2E3, Canada
| | - Rachel Spicer
- Connecticut College, Department of Botany, New London, CT 06320, USA
| | - Stefan G Schreiber
- University of Alberta, Department of Renewable Resources, Edmonton, AB T6G 2E3, Canada
| | - Lenka Plavcová
- University of Hradec Králové, Department of Biology, Rokitanského 62, Hradec Králové, 500 03, Czech Republic
- Charles University, Department of Experimental Plant Biology, Viničná 5, Prague, 128 44, Czech Republic
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34
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Reyes-Rivera J, Rodríguez-Alonso G, Petrone E, Vasco A, Vergara-Silva F, Shishkova S, Terrazas T. Expression of the KNOTTED HOMEOBOX Genes in the Cactaceae Cambial Zone Suggests Their Involvement in Wood Development. Front Plant Sci 2017; 8:218. [PMID: 28316604 PMCID: PMC5334636 DOI: 10.3389/fpls.2017.00218] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 02/06/2017] [Indexed: 05/28/2023]
Abstract
The vascular cambium is a lateral meristem that produces secondary xylem (i.e., wood) and phloem. Different Cactaceae species develop different types of secondary xylem; however, little is known about the mechanisms underlying wood formation in the Cactaceae. The KNOTTED HOMEOBOX (KNOX) gene family encodes transcription factors that regulate plant development. The role of class I KNOX genes in the regulation of the shoot apical meristem, inflorescence architecture, and secondary growth is established in a few model species, while the functions of class II KNOX genes are less well understood, although the Arabidopsis thaliana class II KNOX protein KNAT7 is known to regulate secondary cell wall biosynthesis. To explore the involvement of the KNOX genes in the enormous variability of wood in Cactaceae, we identified orthologous genes expressed in species with fibrous (Pereskia lychnidiflora and Pilosocereus alensis), non-fibrous (Ariocarpus retusus), and dimorphic (Ferocactus pilosus) wood. Both class I and class II KNOX genes were expressed in the cactus cambial zone, including one or two class I paralogs of KNAT1, as well as one or two class II paralogs of KNAT3-KNAT4-KNAT5. While the KNOX gene SHOOTMERISTEMLESS (STM) and its ortholog ARK1 are expressed during secondary growth in the Arabidopsis and Populus stem, respectively, we did not find STM orthologs in the Cactaceae cambial zone, which suggests possible differences in the vascular cambium genetic regulatory network in these species. Importantly, while two class II KNOX paralogs from the KNAT7 clade were expressed in the cambial zone of A. retusus and F. pilosus, we did not detect KNAT7 ortholog expression in the cambial zone of P. lychnidiflora. Differences in the transcriptional repressor activity of secondary cell wall biosynthesis by the KNAT7 orthologs could therefore explain the differences in wood development in the cactus species.
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Affiliation(s)
- Jorge Reyes-Rivera
- Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de MéxicoMexico City, Mexico
| | - Gustavo Rodríguez-Alonso
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de MéxicoCuernavaca, Mexico
| | - Emilio Petrone
- Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de MéxicoMexico City, Mexico
| | - Alejandra Vasco
- Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de MéxicoMexico City, Mexico
| | - Francisco Vergara-Silva
- Jardín Botánico, Instituto de Biología, Universidad Nacional Autónoma de MéxicoMexico City, Mexico
| | - Svetlana Shishkova
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de MéxicoCuernavaca, Mexico
| | - Teresa Terrazas
- Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de MéxicoMexico City, Mexico
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Hamilton JA, El Kayal W, Hart AT, Runcie DE, Arango-Velez A, Cooke JEK. The joint influence of photoperiod and temperature during growth cessation and development of dormancy in white spruce (Picea glauca). Tree Physiol 2016; 36:1432-1448. [PMID: 27449791 DOI: 10.1093/treephys/tpw061] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 05/23/2016] [Indexed: 06/06/2023]
Abstract
Timely responses to environmental cues enable the synchronization of phenological life-history transitions essential for the health and survival of north-temperate and boreal tree species. While photoperiodic cues will remain persistent under climate change, temperature cues may vary, contributing to possible asynchrony in signals influencing developmental and physiological transitions essential to forest health. Understanding the relative contribution of photoperiod and temperature as determinants of the transition from active growth to dormancy is important for informing adaptive forest management decisions that consider future climates. Using a combination of photoperiod (long = 20 h or short = 8 h day lengths) and temperature (warm = 22 °C/16 °C and cool = 8 °C/4 °C day/night, respectively) treatments, we used microscopy, physiology and modeling to comprehensively examine hallmark traits of the growth-dormancy transition-including bud formation, growth cessation, cold hardiness and gas exchange-within two provenances of white spruce [Picea glauca (Moench) Voss] spanning a broad latitude in Alberta, Canada. Following exposure to experimental treatments, seedlings were transferred to favorable conditions, and the depth of dormancy was assessed by determining the timing and ability of spruce seedlings to resume growth. Short photoperiods promoted bud development and growth cessation, whereas longer photoperiods extended the growing season through the induction of lammas growth. In contrast, cool temperatures under both photoperiodic conditions delayed bud development. Photoperiod strongly predicted the development of cold hardiness, whereas temperature predicted photosynthetic rates associated with active growth. White spruce was capable of attaining endodormancy, but its release was environmentally determined. Dormancy depth varied substantially across experimental treatments suggesting that environmental cues experienced within one season could affect growth in the following season, which is particularly important for a determinate species such as white spruce. The joint influence of these environmental cues points toward the importance of including local constant photoperiod and shifting temperature cues into predictive models that consider how climate change may affect northern forests.
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Affiliation(s)
- Jill A Hamilton
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58102, USA
| | - Walid El Kayal
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
- Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada N1G 2W1
| | - Ashley T Hart
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Daniel E Runcie
- Department of Plant Sciences, University of California, Davis, CA 95616, USA
| | - Adriana Arango-Velez
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
- Department of Forestry and Horticulture, The Connecticut Agricultural Experiment Station, New Haven, CT 06504, USA
| | - Janice E K Cooke
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
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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. Front Plant Sci 2016; 7:1422. [PMID: 27713753 PMCID: PMC5032791 DOI: 10.3389/fpls.2016.01422] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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
- *Correspondence: Jacqueline Grima-Pettenati
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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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Qiu Z, Li X, Zhao Y, Zhang M, Wan Y, Cao D, Lu S, Lin J. Genome-wide analysis reveals dynamic changes in expression of microRNAs during vascular cambium development in Chinese fir, Cunninghamia lanceolata. J Exp Bot 2015; 66:3041-54. [PMID: 25795740 DOI: 10.1093/jxb/erv103] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
MicroRNAs (miRNAs) are small noncoding regulatory RNAs that play key roles in the process of plant development. To date, extensive studies of miRNAs have been performed in a few model plants, but few efforts have focused on small RNAs (sRNAs) in conifers because of the lack of reference sequences for their enormous genomes. In this study, Solexa sequencing of three sRNA libraries obtained from dormant, reactivating, and active vascular cambium in Chinese fir (Cunninghamia lanceolata) using tangential cryosectioning identified 20 known miRNA families and 18 novel potential miRNAs, of which nine novel miRNA precursors were validated by RT-PCR and sequencing. More than half of these novel miRNAs displayed stage-specific expression patterns in the vascular cambium. Furthermore, analysing the 103 miRNAs and their predicted targets indicated that about 70% appeared to negatively regulate their targets, of which two target genes involved in the regulation of cambial cell division were validated via RNA ligase-mediated rapid amplification of 5'-cDNA ends (RLM 5'-RACE) and transient co-expression in Nicotiana benthamiana leaves. Interestingly, miRNA156 and miRNA172 may regulate the phase transition in vascular cambium from dormancy to active growth. These results provide new insights into the important regulatory functions of miRNAs in vascular cambium development and wood formation in conifers.
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Affiliation(s)
- Zongbo Qiu
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China College of Life Sciences, Henan Normal University, Xinxiang 453007, China Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Xiaojuan Li
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Yuanyuan Zhao
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Manman Zhang
- College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Yinglang Wan
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Dechang Cao
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Shanfa Lu
- Medicinal Plant Cultivation Research Centre, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China
| | - Jinxing Lin
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
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Chano V, López R, Pita P, Collada C, Soto Á. Proliferation of axial parenchymatic xylem cells is a key step in wound closure of girdled stems in Pinus canariensis. BMC Plant Biol 2015; 15:64. [PMID: 25853802 PMCID: PMC4351838 DOI: 10.1186/s12870-015-0447-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 02/03/2015] [Indexed: 05/04/2023]
Abstract
BACKGROUND Wounds caused by fire, herbivorism, rock impacts, etc. cause the direct loss of photosynthetic, storage and/or vascular tissue. In addition, they may entail other damages, such as desiccation of the exposed internal parts, or become a gateway to infection by fungi and other pathogens. To successfully overcome such injuries, plants must reorganize their meristems or even differentiate new ones, producing new traumatic tissues to cover the wound and restore the vascular connection. RESULTS In this work we analyse the anatomical growth response in conifers after debarking and injuring the vascular cambium, using Pinus canariensis as model species, due to its high wound recovery ability. Conversely to angiosperm woody species, this process is initiated and largely driven by the damaged vascular cambium and not by proliferation in the wound surface. We have detected alterations and switches in the divisions of cambial cells, associated to their position relative to the surface and edges of the wound, resulting in disordered traumatic xylem. We also describe the formation of column-like structures, after girdling, which are in part formed by the proliferation of xylem parenchymatous cells, associated to axial resin ducts. CONCLUSIONS Abundant resinosis on the wound surface, typical of conifers, is an efficient barrier against opportunistic fungi, insects, etc. but it also hinders the healing process directly from the surface. Thus, wound closure must be largely carried out from the wound margins, being a much slower process, which very often remains unconcluded for long years. This work also describes for the first time the proliferation of inner parenchymatous cells to form column-like structures, which accelerates wound closure in girdled P. canariensis. Irregularities in the surface of the healing edge or column-like structures result in the production of disordered vascular tissues, compromising their future functionality, and which must be overcome through the fast restoration of the proper polarity in vascular cambium.
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Affiliation(s)
- Víctor Chano
- />GENFOR, Grupo de Investigación en Genética y Fisiología Forestal. ETSI Montes, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Rosana López
- />GENFOR, Grupo de Investigación en Genética y Fisiología Forestal. ETSI Montes, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Pilar Pita
- />GENFOR, Grupo de Investigación en Genética y Fisiología Forestal. ETSI Montes, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
| | - Carmen Collada
- />GENFOR, Grupo de Investigación en Genética y Fisiología Forestal. ETSI Montes, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
- />Unidad Mixta de Genómica y Ecofisiología Forestal, INIA/UPM, Madrid, Spain
| | - Álvaro Soto
- />GENFOR, Grupo de Investigación en Genética y Fisiología Forestal. ETSI Montes, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
- />Unidad Mixta de Genómica y Ecofisiología Forestal, INIA/UPM, Madrid, Spain
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Qiu Z, Wan L, Chen T, Wan Y, He X, Lu S, Wang Y, Lin J. The regulation of cambial activity in Chinese fir (Cunninghamia lanceolata) involves extensive transcriptome remodeling. New Phytol 2013; 199:708-19. [PMID: 23638988 DOI: 10.1111/nph.12301] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 03/27/2013] [Indexed: 05/03/2023]
Abstract
Chinese fir (Cunninghamia lanceolata), a commercially important tree for the timber and pulp industry, is widely distributed in southern China and northern Vietnam, but its large and complex genome has hindered the development of genomic resources. Few efforts have focused on analysis of the modulation of transcriptional networks in vascular cambium during the transition from active growth to dormancy in conifers. Here, we used Illumina sequencing to analyze the global transcriptome alterations at the different stages of vascular cambium development in Chinese fir. By analyzing dynamic changes in the transcriptome of vascular cambium based on our RNA sequencing (RNA-Seq) data at the dormant, reactivating and active stages, many potentially interesting genes were identified that encoded putative regulators of cambial activity, cell division, cell expansion and cell wall biosynthesis and modification. In particular, the genes involved in transcriptional regulation and hormone signaling were highlighted to reveal their biological importance in the cambium development and wood formation. Our results reveal the dynamics of transcriptional networks and identify potential key components in the regulation of vascular cambium development in Chinese fir, which will contribute to the in-depth study of cambial differentiation and wood-forming candidate genes in conifers.
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Affiliation(s)
- Zongbo Qiu
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
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Dié A, Kitin P, Kouamé FN, Van den Bulcke J, Van Acker J, Beeckman H. Fluctuations of cambial activity in relation to precipitation result in annual rings and intra-annual growth zones of xylem and phloem in teak (Tectona grandis) in Ivory Coast. Ann Bot 2012; 110:861-73. [PMID: 22805529 PMCID: PMC3423803 DOI: 10.1093/aob/mcs145] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 04/26/2012] [Indexed: 05/22/2023]
Abstract
BACKGROUND AND AIMS Teak forms xylem rings that potentially carry records of carbon sequestration and climate in the tropics. These records are only useful when the structural variations of tree rings and their periodicity of formation are known. METHODS The seasonality of ring formation in mature teak trees was examined via correlative analysis of cambial activity, xylem and phloem formation, and climate throughout 1·5 years. Xylem and phloem differentiation were visualized by light microscopy and scanning electron microscopy. KEY RESULTS A 3 month dry season resulted in semi-deciduousness, cambial dormancy and formation of annual xylem growth rings (AXGRs). Intra-annual xylem and phloem growth was characterized by variable intensity. Morphometric features of cambium such as cambium thickness and differentiating xylem layers were positively correlated. Cambium thickness was strongly correlated with monthly rainfall (R(2) = 0·7535). In all sampled trees, xylem growth zones (XGZs) were formed within the AXGRs during the seasonal development of new foliage. When trees achieved full leaf, the xylem in the new XGZs appeared completely differentiated and functional for water transport. Two phloem growth rings were formed in one growing season. CONCLUSIONS The seasonal formation pattern and microstructure of teak xylem suggest that AXGRs and XGZs can be used as proxies for analyses of the tree history and climate at annual and intra-annual resolution.
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Affiliation(s)
| | - Peter Kitin
- Laboratory for wood biology, Royal Museum for Central Africa-Tervuren/Belgium
- USDA Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI 53726, USA
- For correspondence. E-mail
| | | | - Jan Van den Bulcke
- UGCT-Laboratory of Wood Technology, Department of Forest and Water Management, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Joris Van Acker
- UGCT-Laboratory of Wood Technology, Department of Forest and Water Management, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Hans Beeckman
- Laboratory for wood biology, Royal Museum for Central Africa-Tervuren/Belgium
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Abstract
BACKGROUND AND AIMS During their lifetime, tree stems take a series of successive nested shapes. Individual tree growth models traditionally focus on apical growth and architecture. However, cambial growth, which is distributed over a surface layer wrapping the whole organism, equally contributes to plant form and function. This study aims at providing a framework to simulate how organism shape evolves as a result of a secondary growth process that occurs at the cellular scale. METHODS The development of the vascular cambium is modelled as an expanding surface using the level set method. The surface consists of multiple compartments following distinct expansion rules. Growth behaviour can be formulated as a mathematical function of surface state variables and independent variables to describe biological processes. KEY RESULTS The model was coupled to an architectural model and to a forest stand model to simulate cambium dynamics and wood formation at the scale of the organism. The model is able to simulate competition between cambia, surface irregularities and local features. Predicting the shapes associated with arbitrarily complex growth functions does not add complexity to the numerical method itself. CONCLUSIONS Despite their slenderness, it is sometimes useful to conceive of trees as expanding surfaces. The proposed mathematical framework provides a way to integrate through time and space the biological and physical mechanisms underlying cambium activity. It can be used either to test growth hypotheses or to generate detailed maps of wood internal structure.
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Affiliation(s)
- Damien Sellier
- New Zealand Forest Research Institute Ltd, Private Bag 3020, Rotorua 3046, New Zealand.
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Abstract
Many extant land plants display secondary growth originating in a lateral meristem known as vascular cambium. A conspicuous product of secondary growth is wood which dominates terrestrial ecosystem biomass. Despite the economic and ecological significance of the process the underlying molecular mechanism are still poorly understood. We have recently shown that members of the LBD transcription factor family play function in control of secondary growth. Here we propose a mechanistic model of LBD regulatory roles. We also show how these roles may be linked to evolutionary changes in level and pattern of wood formation that provide structural and functional innovations in wood anatomy in relation to species growth habit and biology.
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Affiliation(s)
- Yordan S Yordanov
- Michigan Technological University, Forest Resources and Environmental Science, Houghton, Michigan, USA
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