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Theodorou I, Charrier B. The shift to 3D growth during embryogenesis of kelp species, atlas of cell division and differentiation of Saccharina latissima. Development 2023; 150:dev201519. [PMID: 37882832 PMCID: PMC10660787 DOI: 10.1242/dev.201519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 09/12/2023] [Indexed: 10/27/2023]
Abstract
In most organisms, 3D growth takes place at the onset of embryogenesis. In some brown algae, 3D growth occurs later in development, when the organism consists of several hundred cells. We studied the cellular events that take place when 3D growth is established in the embryo of the brown alga Saccharina, a kelp species. Semi-thin sections, taken from where growth shifts from 2D to 3D, show that 3D growth first initiates from symmetrical cell division in the monolayered lamina, and then is enhanced through a series of asymmetrical cell divisions in a peripheral monolayer of cells called the meristoderm. Then, daughter cells rapidly differentiate into cortical and medullary cells, characterised by their position, size and shape. In essence, 3D growth in kelps is based on a series of differentiation steps that occur rapidly after the initiation of a bilayered lamina, followed by further growth of the established differentiated tissues. Our study depicts the cellular landscape necessary to study cell-fate programming in the context of a novel mode of 3D growth in an organism phylogenetically distant from plants and animals.
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Affiliation(s)
- Ioannis Theodorou
- Laboratory of Integrative Marine Models, Station Biologique de Roscoff, UMR8227, CNRS, Sorbonne University, Place Georges Teissier, 29680 Roscoff, France
- Plant Sciences Department, Faculty of Biosciences, Norwegian University of Life Sciences, NO-1432 Ås, Norway
| | - Bénédicte Charrier
- Laboratory of Integrative Marine Models, Station Biologique de Roscoff, UMR8227, CNRS, Sorbonne University, Place Georges Teissier, 29680 Roscoff, France
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2
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Fraga HPDF, Moraes PEC, Vieira LDN, Guerra MP. Somatic Embryogenesis in Conifers: One Clade to Rule Them All? PLANTS (BASEL, SWITZERLAND) 2023; 12:2648. [PMID: 37514262 PMCID: PMC10385530 DOI: 10.3390/plants12142648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/29/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023]
Abstract
Somatic embryogenesis (SE) in conifers is usually characterized as a multi-step process starting with the development of proembryogenic cell masses and followed by histodifferentiation, somatic embryo development, maturation, desiccation, and plant regeneration. Our current understanding of conifers' SE is mainly derived from studies using Pinaceae species as a model. However, the evolutionary relationships between conifers are not clear. Some hypotheses consider conifers as a paraphyletic group and Gnetales as a closely related clade. In this review, we used an integrated approach in order to cover the advances in knowledge on SE in conifers and Gnetales, discussing the state-of-the-art and shedding light on similarities and current bottlenecks. With this approach, we expect to be able to better understand the integration of these clades within current studies on SE. Finally, the points discussed raise an intriguing question: are non-Pinaceae conifers less prone to expressing embryogenic competence and generating somatic embryos as compared to Pinaceae species? The development of fundamental studies focused on this morphogenetic route in the coming years could be the key to finding a higher number of points in common between these species, allowing the success of the SE of one species to positively affect the success of another.
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Affiliation(s)
| | - Paula Eduarda Cardoso Moraes
- Departamento de Botânica, Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba 81530-000, Brazil
| | - Leila do Nascimento Vieira
- Departamento de Botânica, Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba 81530-000, Brazil
| | - Miguel Pedro Guerra
- Graduate Program in Plant Genetic Resources, Laboratory of Plant Developmental Physiology and Genetics, Federal University of Santa Catarina, Florianópolis 88034-000, Brazil
- Graduate Program in Agricultural and Natural Ecosystems, Federal University of Santa Catarina, Curitibanos Campus, Ulysses Gaboardi Road, Km 3, Curitibanos 89520-000, Brazil
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3
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Lu L, Holt A, Chen X, Liu Y, Knauer S, Tucker EJ, Sarkar AK, Hao Z, Roodbarkelari F, Shi J, Chen J, Laux T. miR394 enhances WUSCHEL-induced somatic embryogenesis in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2023; 238:1059-1072. [PMID: 36751948 DOI: 10.1111/nph.18801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
Many plant species can give rise to embryos from somatic cells after a simple hormone treatment, illustrating the remarkable developmental plasticity of differentiated plant cells. However, many species are recalcitrant to somatic embryo formation for unknown reasons, which poses a significant challenge to agriculture, where somatic embryogenesis is an important tool to propagate desired genotypes. The micro-RNA394 (miR394) promotes shoot meristem maintenance in Arabidopsis thaliana, but the underlying mechanisms have remained elusive. We analyzed whether miR394 affects indirect somatic embryogenesis and determined the transcriptome of embryogenic callus upon miR394-enhanced somatic embryogenesis. We show that ectopic miR394 expression enhances somatic embryogenesis in the recalcitrant Ler accession when co-expressed with the transcription factor WUSCHEL (WUS) and that miR394 acts in this process through silencing the target LEAF CURLING RESPONSIVENESS (LCR). Furthermore, we show that higher endogenous miR394 levels are required for the elevated embryogenic potential of the Columbia accession compared with Ler, providing a mechanistic explanation for this natural variation. Our transcriptional analysis provides a framework for miR394 function in regulating pluripotency by expanding WUS-mediated direct transcriptional repression.
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Affiliation(s)
- Lu Lu
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
- Signalling Research Centres BIOSS and CIBSS, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Anna Holt
- Signalling Research Centres BIOSS and CIBSS, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Xinying Chen
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Yang Liu
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Steffen Knauer
- Signalling Research Centres BIOSS and CIBSS, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Elise J Tucker
- Signalling Research Centres BIOSS and CIBSS, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Ananda Kumar Sarkar
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Zhaodong Hao
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Farshad Roodbarkelari
- Signalling Research Centres BIOSS and CIBSS, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Jisen Shi
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Jinhui Chen
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Thomas Laux
- Signalling Research Centres BIOSS and CIBSS, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
- Sino-German Joint Research Center on Agricultural Biology, Shandong Agricultural University, Tai'an, Shandong, 271018, China
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Hao Z, Wu H, Zheng R, Li R, Zhu Z, Chen Y, Lu Y, Cheng T, Shi J, Chen J. The plant peptide hormone phytosulfokine promotes somatic embryogenesis by maintaining redox homeostasis in Cunninghamia lanceolata. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 113:716-733. [PMID: 36575581 DOI: 10.1111/tpj.16077] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
Somatic embryogenesis (SE) is widely used for studying the mechanisms of embryo development. However, little is known about the underlying mechanisms, especially in woody plants. Previous studies have established an SE system for Chinese fir (Cunninghamia lanceolata), but this system is genotype-dependent, which limits its application in practice. Here, we found that phytosulfokine (PSK), a plant peptide hormone, can not only increase SE efficiency, but also establish SE in recalcitrant genotypes of C. lanceolata. Proembryogenic mass (PEM) browning and determination of hydrogen peroxide (H2 O2 ) content by 2',7'-dichlorofluorescein staining indicated that a reactive oxygen species (ROS) burst occurred rapidly after PEMs were transferred to SE induction medium. Transcriptome analysis and quantitative reverse transcriptase-PCR validation showed that PSK treatment helped to maintain ROS homeostasis by decreasing the activity of peroxidases in early SE induction. This PSK-regulated redox microenvironment might be helpful to induce expression of SE-related genes like WOX2 in early SE induction. Further analyses suggested that PSK promotes SE induction in C. lanceolata partially through decreasing H2 O2 levels, which is necessary but not sufficient for SE induction in recalcitrant genotypes of C. lanceolata. Furthermore, heterologous overexpression of ClPSK in Arabidopsis led to enhanced SE induction and resistance to H2 O2 stress. Taken together, our study reveals a biological function for the plant peptide hormone PSK, extends our knowledge about SE in woody trees, and provides a valuable tool for establishing an efficient and genotype-independent SE system in C. lanceolata and other coniferous trees.
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Affiliation(s)
- Zhaodong Hao
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Hua Wu
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Renhua Zheng
- Fujian Academy of Forestry, Fuzhou, 350012, Fujian, China
| | - Rui Li
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Zeli Zhu
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Ya Chen
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Ye Lu
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Tielong Cheng
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Jisen Shi
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
| | - Jinhui Chen
- Key Laboratory of Forest Genetics and Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, Jiangsu, China
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Hassani SB, Trontin JF, Raschke J, Zoglauer K, Rupps A. Constitutive Overexpression of a Conifer WOX2 Homolog Affects Somatic Embryo Development in Pinus pinaster and Promotes Somatic Embryogenesis and Organogenesis in Arabidopsis Seedlings. FRONTIERS IN PLANT SCIENCE 2022; 13:838421. [PMID: 35360299 PMCID: PMC8960953 DOI: 10.3389/fpls.2022.838421] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
Although full sequence data of several embryogenesis-related genes are available in conifers, their functions are still poorly understood. In this study, we focused on the transcription factor WUSCHEL-related HOMEOBOX 2 (WOX2), which is involved in determination of the apical domain during early embryogenesis, and is required for initiation of the stem cell program in the embryogenic shoot meristem of Arabidopsis. We studied the effects of constitutive overexpression of Pinus pinaster WOX2 (PpWOX2) by Agrobacterium-mediated transformation of P. pinaster somatic embryos and Arabidopsis seedlings. Overexpression of PpWOX2 during proliferation and maturation of somatic embryos of P. pinaster led to alterations in the quantity and quality of cotyledonary embryos. In addition, transgenic somatic seedlings of P. pinaster showed non-embryogenic callus formation in the region of roots and subsequently inhibited root growth. Overexpression of PpWOX2 in Arabidopsis promoted somatic embryogenesis and organogenesis in a part of the transgenic seedlings of the first and second generations. A concomitant increased expression of endogenous embryogenesis-related genes such as AtLEC1 was detected in transgenic plants of the first generation. Various plant phenotypes observed from single overexpressing transgenic lines of the second generation suggest some significant interactions between PpWOX2 and AtWOX2. As an explanation, functional redundancy in the WOX family is suggested for seed plants. Our results demonstrate that the constitutive high expression of PpWOX2 in Arabidopsis and P. pinaster affected embryogenesis-related traits. These findings further support some evolutionary conserved roles of this gene in embryo development of seed plants and have practical implications toward somatic embryogenesis induction in conifers.
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Affiliation(s)
- Seyedeh Batool Hassani
- Department of Plant Systematics and Evolution, Institute of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | | | - Juliane Raschke
- Department of Plant Systematics and Evolution, Institute of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Kurt Zoglauer
- Department of Plant Systematics and Evolution, Institute of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Andrea Rupps
- Department of Plant Systematics and Evolution, Institute of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
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Vetrici MA, Yevtushenko DP, Misra S. Douglas-fir LEAFY COTYLEDON1 ( PmLEC1) is an active transcription factor during zygotic and somatic embryogenesis. PLANT DIRECT 2021; 5:e00333. [PMID: 34355111 PMCID: PMC8320655 DOI: 10.1002/pld3.333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 06/13/2023]
Abstract
Douglas-fir (Pseudotsuga menziesii) is one of the world's premier lumber species and somatic embryogenesis (SE) is the most promising method for rapid propagation of superior tree genotypes. The development and optimization of SE protocols in conifers is hindered by a lack of knowledge of the molecular basis of embryogenesis and limited sequence data. In Arabidopsis, the LEAFY COTYLEDON1 (AtLEC1) gene is a master regulator of embryogenesis that induces SE when expressed ectopically. We isolated the LEC1 homologue from Douglas-fir, designated as PmLEC1. PmLEC1 expression in somatic embryos and developing seeds demonstrated a unique, alternating pattern of expression with the highest levels during early stages of embryogenesis. PmLEC1 protein accumulation during seed development correlated with its transcriptional levels during early embryogenesis; however, substantial protein levels persisted until 2 weeks on germination medium. Treatment of mature, stratified seeds with 2,4-epibrassinolide, sorbitol, mannitol, or NaCl upregulated PmLEC1 expression, which may provide strategies to induce SE from mature tissues. Sequence analysis of the PmLEC1 gene revealed a 5' UTR intron containing binding sites for transcription factors (TFs), such as ABI3, LEC2, FUS3, and AGL15, which are critical regulators of embryogenesis in angiosperms. Regulatory elements for these and other seed-specific TFs and biotic and abiotic signals were identified within the PmLEC1 locus. Most importantly, functional analysis of PmLEC1 showed that it rescued the Arabidopsis lec1-1 null mutant and, in the T2 generation, led to the development of embryo-like structures, indicating a key role of PmLEC1 in the regulation of embryogenesis.
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Affiliation(s)
- Mariana A. Vetrici
- Department of Biological SciencesUniversity of LethbridgeLethbridgeABCanada
- Centre for Forest BiologyDepartment of Biochemistry & MicrobiologyUniversity of VictoriaVictoriaBCCanada
| | | | - Santosh Misra
- Centre for Forest BiologyDepartment of Biochemistry & MicrobiologyUniversity of VictoriaVictoriaBCCanada
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Moler ERV, Kolb T, Brady A, Palmiero BN, Wallace TR, Waring KM, Whipple AV. Plant developmental stage influences responses of Pinus strobiformis seedlings to experimental warming. PLANT-ENVIRONMENT INTERACTIONS (HOBOKEN, N.J.) 2021; 2:148-164. [PMID: 37283863 PMCID: PMC10168050 DOI: 10.1002/pei3.10055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 04/17/2021] [Accepted: 04/23/2021] [Indexed: 06/08/2023]
Abstract
Seedling emergence, survival, morphological and physiological traits, and oxidative stress resistance of southwestern white pine (Pinus strobiformis Engelm.) were studied in response to warming treatments applied during embryogenesis, germination, and early seedling growth. Daytime air temperature surrounding cones in tree canopies was warmed by +2.1°C during embryo development. Resulting seeds and seedlings were assigned to three thermal regimes in growth chambers, with each regime separated by 4°C to encompass the wide range of temperatures observed over space and time across the species' range, plus the effect of heat waves coupled with a high carbon emissions scenario of climate warming. The embryo warming treatment reduced percent seedling emergence in all germination and growth environments and reduced mortality of seedlings grown in the warmest environment. Warm thermal regimes during early seedling growth increased subsequent seedling resistance to oxidative stress and transpirational water use. Experimental warming during seed development, germination, and seedling growth affected seedling emergence and survival. Oxidative stress resistance, morphology, and water relations were affected only by warming imposed during germination and seedling growth. This work explores potential outcomes of climate warming on multiple dimensions of seedling performance and uniquely illustrates that plant responses to heat vary with plant developmental stage in addition to the magnitude of temperature change.
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Affiliation(s)
| | - Thomas Kolb
- School of ForestryNorthern Arizona UniversityFlagstaffAZUSA
| | - Anne Brady
- Department of Biological SciencesNorthern Arizona UniversityFlagstaffAZUSA
| | | | | | | | - Amy Vaughn Whipple
- Department of Biological SciencesNorthern Arizona UniversityFlagstaffAZUSA
- Center for Adaptive Western LandscapesNorthern Arizona UniversityFlagstaffAZUSA
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Tretyakova IN, Mineev VV. Reproductive Potential of Conifers, Somatic Embryogenesis and Apomixis. Russ J Dev Biol 2021. [DOI: 10.1134/s1062360421020089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Yan J, Peng P, Duan G, Lin T, Bai Y. Multiple analyses of various factors affecting the plantlet regeneration of Picea mongolica (H. Q. Wu) W.D. Xu from somatic embryos. Sci Rep 2021; 11:6694. [PMID: 33758217 PMCID: PMC7987962 DOI: 10.1038/s41598-021-83948-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 01/28/2021] [Indexed: 01/31/2023] Open
Abstract
Picea mongolica, a native species with excellent industrial wood quality and strong sand-fixing capacity, may be utilized in construction of urban green spaces in arid areas in China. However, now the sustainability of the ecosystems where this species grows is at serious risk due to a lack of natural regeneration. In this study, we developed an efficient regeneration system and comprehensively analyzed various factors affecting somatic embryogenesis (SE) using zygotic embryos as explants. We identified the optimal plant growth regulators (PGRs) performance and the best donor trees (k81) for the generation of somatic embryos (SEMs). Additionally, we confirmed that the positive developmental window of SEMs initiation was at the end of July to early August, which is when zygotic embryos was at the late embryogeny. In this time period, specific transcripts associated with the regulation of epigenetic modifications, plant hormone-related genes, and embryonic development-related transcription factors play important roles for early SEMs initiation. These results may provide a valuable resource for vegetative propagation of Picea mongolica. Our results may help to establish a reliable protocol for plantlet regeneration, which may facilitate urban greening applications and industrialization in arid areas.
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Affiliation(s)
- Jia Yan
- grid.411638.90000 0004 1756 9607Institute of Forest Tree Genetic Breeding, Forestry College, Inner Mongolia Agricultural University, Xinjian Street 275, Hohhot City, Inner Mongolia China
| | - Peng Peng
- grid.411638.90000 0004 1756 9607Institute of Forest Tree Genetic Breeding, Forestry College, Inner Mongolia Agricultural University, Xinjian Street 275, Hohhot City, Inner Mongolia China
| | - Guozhen Duan
- grid.262246.60000 0004 1765 430XInstitute of Forestry, Academy of Agricultural and Forestry Sciences, Qinghai University, Ning da Road 251, Xining City, Qinghai Province China
| | - Tao Lin
- grid.411638.90000 0004 1756 9607Institute of Forest Tree Genetic Breeding, Forestry College, Inner Mongolia Agricultural University, Xinjian Street 275, Hohhot City, Inner Mongolia China
| | - Yu´e Bai
- grid.411638.90000 0004 1756 9607Institute of Forest Tree Genetic Breeding, Forestry College, Inner Mongolia Agricultural University, Xinjian Street 275, Hohhot City, Inner Mongolia China
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Alves A, Cordeiro D, Correia S, Miguel C. Small Non-Coding RNAs at the Crossroads of Regulatory Pathways Controlling Somatic Embryogenesis in Seed Plants. PLANTS (BASEL, SWITZERLAND) 2021; 10:504. [PMID: 33803088 PMCID: PMC8001652 DOI: 10.3390/plants10030504] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 11/25/2022]
Abstract
Small non-coding RNAs (sncRNAs) are molecules with important regulatory functions during development and environmental responses across all groups of terrestrial plants. In seed plants, the development of a mature embryo from the zygote follows a synchronized cell division sequence, and growth and differentiation events regulated by highly regulated gene expression. However, given the distinct features of the initial stages of embryogenesis in gymnosperms and angiosperms, it is relevant to investigate to what extent such differences emerge from differential regulation mediated by sncRNAs. Within these, the microRNAs (miRNAs) are the best characterized class, and while many miRNAs are conserved and significantly represented across angiosperms and other seed plants during embryogenesis, some miRNA families are specific to some plant lineages. Being a model to study zygotic embryogenesis and a relevant biotechnological tool, we systematized the current knowledge on the presence and characterization of miRNAs in somatic embryogenesis (SE) of seed plants, pinpointing the miRNAs that have been reported to be associated with SE in angiosperm and gymnosperm species. We start by conducting an overview of sncRNA expression profiles in the embryonic tissues of seed plants. We then highlight the miRNAs described as being involved in the different stages of the SE process, from its induction to the full maturation of the somatic embryos, adding references to zygotic embryogenesis when relevant, as a contribution towards a better understanding of miRNA-mediated regulation of SE.
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Affiliation(s)
- Ana Alves
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisboa, Portugal;
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Daniela Cordeiro
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; (D.C.); (S.C.)
| | - Sandra Correia
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; (D.C.); (S.C.)
| | - Célia Miguel
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisboa, Portugal;
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portugal
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Maruyama TE, Ueno S, Hosoi Y, Miyazawa SI, Mori H, Kaneeda T, Bamba Y, Itoh Y, Hirayama S, Kawakami K, Moriguchi Y. Somatic Embryogenesis Initiation in Sugi (Japanese Cedar, Cryptomeria japonica D. Don): Responses from Male-Fertile, Male-Sterile, and Polycross-Pollinated-Derived Seed Explants. PLANTS (BASEL, SWITZERLAND) 2021; 10:398. [PMID: 33669646 PMCID: PMC7922571 DOI: 10.3390/plants10020398] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/17/2021] [Accepted: 02/17/2021] [Indexed: 11/25/2022]
Abstract
This study aimed to obtain information from several embryogenic cell (EC) genotypes analyzing the factors that affect somatic embryogenesis (SE) initiation in sugi (Cryptomeria japonica, Cupressaceae) to apply them in the improvement of protocols for efficient induction of embryogenic cell lines (ECLs). The results of several years of experiments including studies on the influence of initial explant, seed collection time, and explant genotype as the main factors affecting SE initiation from male-fertile, male-sterile, and polycross-pollinated-derived seeds are described. Initiation frequencies depending on the plant genotype varied from 1.35 to 57.06%. The best induction efficiency was achieved when seeds were collected on mid-July using the entire megagametophyte as initial explants. The extrusion of ECs started approximately after 2 weeks of culture, and the establishment of ECLs was observed mostly 4 weeks after extrusion on media with or without plant growth regulators (PGRs). Subsequently, induced ECLs were maintained and proliferated on media with PGRs by 2-3-week-interval subculture routines. Although, the initial explant, collection time, and culture condition played important roles in ECL induction, the genotype of the plant material of sugi was the most influential factor in SE initiation.
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Affiliation(s)
- Tsuyoshi E. Maruyama
- Department of Research Planning and Coordination, Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba 305-8687, Japan
| | - Saneyoshi Ueno
- Department of Forest Molecular Genetics and Biotechnology, Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba 305-8687, Japan; (S.U.); (Y.H.); (S.-I.M.); (H.M.)
| | - Yoshihisa Hosoi
- Department of Forest Molecular Genetics and Biotechnology, Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba 305-8687, Japan; (S.U.); (Y.H.); (S.-I.M.); (H.M.)
| | - Shin-Ichi Miyazawa
- Department of Forest Molecular Genetics and Biotechnology, Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba 305-8687, Japan; (S.U.); (Y.H.); (S.-I.M.); (H.M.)
| | - Hideki Mori
- Department of Forest Molecular Genetics and Biotechnology, Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba 305-8687, Japan; (S.U.); (Y.H.); (S.-I.M.); (H.M.)
| | - Takumi Kaneeda
- Graduate School of Science and Technology, Niigata University, Ikarashi 8050, Niigata 950-2181, Japan; (T.K.); (Y.M.)
| | - Yukiko Bamba
- Niigata Prefectural Forest Research Institute, Unotoro 2249-5, Niigata 958-0264, Japan; (Y.B.); (Y.I.)
| | - Yukiko Itoh
- Niigata Prefectural Forest Research Institute, Unotoro 2249-5, Niigata 958-0264, Japan; (Y.B.); (Y.I.)
| | - Satoko Hirayama
- Agriculture and Forestry Promotion Department, Niigata Regional Promotion Bureau, Niigata Prefectural Government, Hodojima 2009, Niigata 956-8635, Japan;
| | | | - Yoshinari Moriguchi
- Graduate School of Science and Technology, Niigata University, Ikarashi 8050, Niigata 950-2181, Japan; (T.K.); (Y.M.)
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12
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Goeten D, Rogge-Renner GD, Schmidt ÉC, Bouzon ZL, Farias-Soares FL, Guerra MP, Steiner N. Updating embryonic ontogenesis in Araucaria angustifolia: from Burlingame (1915) to the present. PROTOPLASMA 2020; 257:931-948. [PMID: 31950285 DOI: 10.1007/s00709-020-01481-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 01/08/2020] [Indexed: 06/10/2023]
Abstract
This study addresses gaps in our understanding of pre-fertilization and archegonia development and reinterprets embryonic ontogenesis from Burlingame (Bot Gaz 59:1-39, 1915) to the present based on timescale and structural features allowing us to determine functionally and developmentally accurate terminology for all these stages in A. angustifolia. Different from previous reports, only after pollination, pre-fertilization tissue development occurs (0-13 months after pollination (MAP)) and gives rise to a mature megagametophyte. During all this period, pollen is in a dormant state at the microphyla, and pollen tube germination in nucellus tissue is only observed at the stage of archegonia formation (13 MAP) and not at the free nuclei stage as reported before. For the first time, 14 months after pollination, a fertilization window was indicated, and at 15 MAP, the polyzygotic polyembryony from different archegonia was also seen. After that, subordinated proembryo regression occurs and at least three embryonic developmental stages of dominant embryo were characterized: proembryogenic, early embryogenic, and late embryogenic (15-23 MAP). Along these stages, histochemical and ultrastructural analyses suggest the occurrence of cell death in suspensor and in cap cells of dominant embryo that was not previously reported. The differentiation of meristems, procambium, pith, and cortex tissues in late embryogenic stage was detailed. The morphohistological characterization of pre-fertilization and embryonic stages, together with the timescale of megastrobili development, warranted a referential map of female reproductive structure in this species.
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Affiliation(s)
- Daniela Goeten
- Plant Physiology Laboratory, Department of Botany, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, Brazil
| | - Gladys D Rogge-Renner
- Biological Sciences Department, University of Joinville Region, Joinville, SC, 89219-710, Brazil
| | - Éder C Schmidt
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, Florianópolis, SC, 88040-400, Brazil
| | - Zenilda L Bouzon
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, Florianópolis, SC, 88040-400, Brazil
| | - Francine L Farias-Soares
- Plant Developmental Physiology and Genetics Laboratory, Department of Plant Science, Federal University of Santa Catarina, Florianópolis, SC, 88034-001, Brazil
| | - Miguel P Guerra
- Plant Developmental Physiology and Genetics Laboratory, Department of Plant Science, Federal University of Santa Catarina, Florianópolis, SC, 88034-001, Brazil
- Graduate Program in Agricultural and Natural Ecosystems, Federal University of Santa Catarina, Curitibanos, SC, 89520-000, Brazil
| | - Neusa Steiner
- Plant Physiology Laboratory, Department of Botany, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
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13
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Tretyakova IN, Rogozhin EA, Pak ME, Petukhova IA, Shuklina AS, Pahomova AP, Sadykova VS. Use of Plant Antimicrobial Peptides in in vitro Embryogenic Cultures of Larix sibirica. BIOL BULL+ 2020. [DOI: 10.1134/s1062359020030097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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14
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Ouyang L, Wang Z, Li L, Chen B. Physiological parameters and differential expression analysis of N-phenyl- N'-[6-(2-chlorobenzothiazol)-yl] urea-induced callus of Eucalyptus urophylla × Eucalyptus grandis. PeerJ 2020; 8:e8776. [PMID: 32206452 PMCID: PMC7075363 DOI: 10.7717/peerj.8776] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 02/21/2020] [Indexed: 02/05/2023] Open
Abstract
In this study, we analyzed differences in the enzyme activities and transcriptomes of embryogenic and non-embryogenic calli to gain insights for improving the success of tissue culture-based breeding. A total of 2,856 differentially expressed genes (DEGs; 1,632 up-regulated and 1,224 down-regulated) were identified based on RNA sequencing and verified by reverse transcription quantitative polymerase chain reaction. Gene set enrichment analysis revealed that many of the up-regulated DEGs in embryogenic callus were enriched in the photosynthesis processes. Furthermore, the enzyme activity, hormone content, and cytokinin oxidase/dehydrogenase (CKX) gene expression analyses were found to be consistent with the transcriptome results. Cytokinin biosynthesis in N-phenyl-N′-[6-(2-chlorobenzothiazol)-yl] urea (PBU)-induced embryogenic callus increased owing to CKX repression. Measurement of endogenous hormones by high-performance liquid chromatography revealed that, compared with non-embryogenic callus, in embryogenic callus, the indole-3-acetic acid, abscisic acid and trans-zeatin riboside content had significantly higher values of 129.7, 127.8 and 78.9 ng/g, respectively. Collectively, the findings of this study will provide a foundation for elucidating the molecular mechanisms underlying embryogenic callus differentiation and can potentially contribute to developing procedures aimed at enhancing the success of callus-based plant regeneration.
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Affiliation(s)
- Lejun Ouyang
- College of Biological and Food Engineering, Guangdong University of Petrochemical Technology, Maoming, China
| | - Zechen Wang
- College of Biological and Food Engineering, Guangdong University of Petrochemical Technology, Maoming, China
| | - Limei Li
- College of Biological and Food Engineering, Guangdong University of Petrochemical Technology, Maoming, China
| | - Baoling Chen
- College of Biological and Food Engineering, Guangdong University of Petrochemical Technology, Maoming, China
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15
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De La Torre AR, Piot A, Liu B, Wilhite B, Weiss M, Porth I. Functional and morphological evolution in gymnosperms: A portrait of implicated gene families. Evol Appl 2020; 13:210-227. [PMID: 31892953 PMCID: PMC6935586 DOI: 10.1111/eva.12839] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 04/25/2019] [Accepted: 07/02/2019] [Indexed: 12/12/2022] Open
Abstract
Gymnosperms diverged from their sister plant clade of flowering plants 300 Mya. Morphological and functional divergence between the two major seed plant clades involved significant changes in their reproductive biology, water-conducting systems, secondary metabolism, stress defense mechanisms, and small RNA-mediated epigenetic silencing. The relatively recent sequencing of several gymnosperm genomes and the development of new genomic resources have enabled whole-genome comparisons within gymnosperms, and between angiosperms and gymnosperms. In this paper, we aim to understand how genes and gene families have contributed to the major functional and morphological differences in gymnosperms, and how this information can be used for applied breeding and biotechnology. In addition, we have analyzed the angiosperm versus gymnosperm evolution of the pleiotropic drug resistance (PDR) gene family with a wide range of functionalities in plants' interaction with their environment including defense mechanisms. Some of the genes reviewed here are newly studied members of gene families that hold potential for biotechnological applications related to commercial and pharmacological value. Some members of conifer gene families can also be exploited for their potential in phytoremediation applications.
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Affiliation(s)
| | - Anthony Piot
- Department of Wood and Forest SciencesLaval UniversityQuebec CityQuebecCanada
- Institute for System and Integrated Biology (IBIS)Laval UniversityQuebec CityQuebecCanada
- Centre for Forest Research (CEF)Laval UniversityQuebec CityQuebecCanada
| | - Bobin Liu
- School of ForestryNorthern Arizona UniversityFlagstaffAZUSA
- College of ForestryFujian Agricultural and Forestry UniversityFuzhouFujianChina
| | | | - Matthew Weiss
- School of ForestryNorthern Arizona UniversityFlagstaffAZUSA
| | - Ilga Porth
- Department of Wood and Forest SciencesLaval UniversityQuebec CityQuebecCanada
- Institute for System and Integrated Biology (IBIS)Laval UniversityQuebec CityQuebecCanada
- Centre for Forest Research (CEF)Laval UniversityQuebec CityQuebecCanada
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16
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Vuosku J, Sutela S. Microscopical Detection of Cell Death Processes During Scots Pine Zygotic Embryogenesis. Methods Mol Biol 2020; 2122:223-237. [PMID: 31975306 DOI: 10.1007/978-1-0716-0342-0_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Programmed cell death (PCD) processes are essential in the plant embryogenesis. To understand how PCD operates in a developing seed, the dying cells need to be identified in relation to their surviving neighbors. This can be accomplished by the means of in situ visualization of fragmented DNA-a well-known hallmark of PCD. In the developing Scots pine (Pinus sylvestris L.) seed, several tissues die via morphologically different PCD processes during the embryogenesis. Here, we describe the protocols for the characterization of Scots pine seeds at the early and late developmental stages and, further, the localization of nucleic acids and DNA fragmentation by the acridine orange staining and TUNEL (terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick end labeling) assay in the dying seed tissues.
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Affiliation(s)
- Jaana Vuosku
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland.
| | - Suvi Sutela
- Natural Resources Institute Finland (Luke), Helsinki, Finland
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17
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Maruyama TE, Hosoi Y. Progress in Somatic Embryogenesis of Japanese Pines. FRONTIERS IN PLANT SCIENCE 2019; 10:31. [PMID: 30745904 PMCID: PMC6360188 DOI: 10.3389/fpls.2019.00031] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 01/09/2019] [Indexed: 05/23/2023]
Abstract
Somatic embryogenesis (SE) in not only one of the most promising techniques for mass propagation of selected trees, but also is a valuable tool for basic research studies in cell biology and genetic engineering, and it allows the long-term ex situ conservation of genetic resources by cryopreservation techniques. This review reports the most recent progress in SE, protoplast culture, and cryopreservation of four important Japanese pines (Pinus thunbergii, Pinus densiflora, Pinus armandii var. amamiana, and Pinus luchuensis). Induction of embryogenic tissues (ET), embryogenic culture maintenance/proliferation, production of somatic embryos, germination, and conversion to plants are described focusing on the protocols most commonly reported for plant production in Pinus species through to SE.
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Affiliation(s)
- Tsuyoshi E. Maruyama
- Department of Forest Molecular Genetics and Biotechnology, Forestry and Forest Products Research Institute, Tsukuba, Japan
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18
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Histology versus phylogeny: Viewing plant embryogenesis from an evo-devo perspective. Curr Top Dev Biol 2019; 131:545-564. [DOI: 10.1016/bs.ctdb.2018.11.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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19
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Egertsdotter U, Ahmad I, Clapham D. Automation and Scale Up of Somatic Embryogenesis for Commercial Plant Production, With Emphasis on Conifers. FRONTIERS IN PLANT SCIENCE 2019; 10:109. [PMID: 30833951 PMCID: PMC6388443 DOI: 10.3389/fpls.2019.00109] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 01/23/2019] [Indexed: 05/19/2023]
Abstract
For large scale production of clonal plants, somatic embryogenesis (SE) has many advantages over other clonal propagation methods such as the rooting of cuttings. In particular, the SE process is more suited to scale up and automation, thereby reducing labor costs and increasing the reliability of the production process. Furthermore, the plants resulting from SE closely resemble those from seeds, as somatic embryos, like zygotic (seed) embryos, develop with good connection between root and shoot, and without the plagiotropism often associated with propagation by cuttings. For practical purposes in breeding programs and for deployment of elite clones, it is valuable that a virtually unlimited number of SE plants can be generated from one original seed embryo; and SE cultures (clones) can be cryostored for at least 20 years, allowing long-term testing of clones. To date, there has however been limited use of SE for large-scale plant production mainly because without automation it is labor-intensive. Development of automation is particularly attractive in countries with high labor costs, where conifer forestry is often of great economic importance. Various approaches for automating SE processes are under investigation and the progress is reviewed here, with emphasis on conifers. These approaches include simplification of culture routines with preference for liquid rather than solid cultures, use of robotics and automation for the harvest of selected individual mature embryos, followed by automated handling of germination and subsequent planting. Different approaches to handle the processes of somatic embryogenesis in conifers are outlined below, followed by an update on efforts to automate the different steps, which are nearing an operational stage.
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Affiliation(s)
- Ulrika Egertsdotter
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, Umeå, Sweden
- G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, United States
- *Correspondence: Ulrika Egertsdotter
| | - Iftikhar Ahmad
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - David Clapham
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden
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20
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Pais MS. Somatic Embryogenesis Induction in Woody Species: The Future After OMICs Data Assessment. FRONTIERS IN PLANT SCIENCE 2019; 10:240. [PMID: 30984207 PMCID: PMC6447717 DOI: 10.3389/fpls.2019.00240] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/12/2019] [Indexed: 05/15/2023]
Abstract
Very early somatic embryogenesis has been recognized as a powerful method to propagate plants in vitro. For some woody species and in particular for some coniferous trees, somatic embryogenesis induction has become a routine procedure. For the majority, the application of this technology presents yet many limitations especially due to the genotype, the induction conditions, the number of embryos produced, maturation, and conversion, among other factors that compromise the systematic use of somatic embryogenesis for commercial purposes especially of woody species and forest trees in particular. The advancements obtained on somatic embryogenesis in Arabidopsis and the development of OMIC technologies allowed the characterization of genes and the corresponding proteins that are conserved in woody species. This knowledge will help in understanding the molecular mechanisms underlying the complex regulatory networks that control somatic embryogenesis in woody plants. In this revision, we report on developments of OMICs (genomics, transcriptomics, metabolomics, and proteomics) applied to somatic embryogenesis induction and its contribution for understanding the change of fate giving rise to the expression of somatic embryogenesis competence.
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21
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Brunoni F, Ljung K, Bellini C. Control of root meristem establishment in conifers. PHYSIOLOGIA PLANTARUM 2019; 165:81-89. [PMID: 29920700 DOI: 10.1111/ppl.12783] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 06/05/2018] [Accepted: 06/08/2018] [Indexed: 06/08/2023]
Abstract
The evolution of terrestrial plant life was made possible by the establishment of a root system, which enabled plants to migrate from aquatic to terrestrial habitats. During evolution, root organization has gradually progressed from a very simple to a highly hierarchical architecture. Roots are initiated during embryogenesis and branch afterward through lateral root formation. Additionally, adventitious roots can be formed post-embryonically from aerial organs. Induction of adventitious roots (ARs) forms the basis of the vegetative propagation via cuttings in horticulture, agriculture and forestry. This method, together with somatic embryogenesis, is routinely used to clonally multiply conifers. In addition to being utilized as propagation techniques, adventitious rooting and somatic embryogenesis have emerged as versatile models to study cellular and molecular mechanisms of embryo formation and organogenesis of coniferous species. Both formation of the embryonic root and the AR primordia require the establishment of auxin gradients within cells that coordinate the developmental response. These processes also share key elements of the genetic regulatory networks that, e.g. are triggering cell fate. This minireview gives an overview of the molecular control mechanisms associated with root development in conifers, from initiation in the embryo to post-embryonic formation in cuttings.
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Affiliation(s)
- Federica Brunoni
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Karin Ljung
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Catherine Bellini
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
- Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, Versailles, France
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22
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Vondrakova Z, Dobrev PI, Pesek B, Fischerova L, Vagner M, Motyka V. Profiles of Endogenous Phytohormones Over the Course of Norway Spruce Somatic Embryogenesis. FRONTIERS IN PLANT SCIENCE 2018; 9:1283. [PMID: 30237806 PMCID: PMC6136392 DOI: 10.3389/fpls.2018.01283] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 08/16/2018] [Indexed: 05/19/2023]
Abstract
Conifer somatic embryogenesis (SE) is a process driven by exogenously supplied plant growth regulators (PGRs). Exogenous PGRs and endogenous phytohormones trigger particular ontogenetic events. Complex mechanisms involving a number of endogenous phytohormones control the differentiation of cells and tissues, as well as the establishment of structures and organs. Most of the mechanisms and hormonal functions in the SE of conifers have not yet been described. With the aim to better understand these mechanisms, we provided detailed analysis of the spectrum of endogenous phytohormones over the course of SE in Norway spruce (Picea abies). Concentrations of endogenous phytohormones including auxins, cytokinins (CKs), abscisic acid (ABA), jasmonates, and salicylic acid (SA) in somatic P. abies embryos were analyzed by HPLC-ESI-MS/MS. The results revealed that the concentrations of particular phytohormone classes varied substantially between proliferation, maturation, desiccation, and germination. Endogenous ABA showed a maximum concentration at the maturation stage, which reflected the presence of exogenous ABA in the medium and demonstrated its efficient perception by the embryos as a prerequisite for their further development. Auxins also had concentration maxima at the maturation stage, suggesting a role in embryo polarization. Endogenous jasmonates were detected in conifer somatic embryos for the first time, and reached maxima at germination. According to our knowledge, we have presented evidence for the involvement of the non-indole auxin phenylacetic acid, cis-zeatin- and dihydrozeatin-type CKs and SA in SE for the first time. The presented results represent the currently most comprehensive overview of plant hormone levels in embryos throughout the whole process of conifer SE. The differences in concentrations of various classes of phytohormones over the proliferation, maturation, desiccation, and germination in somatic P. abies embryos clearly indicate correlations between endogenous phytohormone profiles and particular developmental stages of the SE of conifers.
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Affiliation(s)
- Zuzana Vondrakova
- Laboratory of Biologically Active Compounds, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
| | - Petre I. Dobrev
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
| | - Bedrich Pesek
- Laboratory of Mass Spectrometry, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
| | - Lucie Fischerova
- Laboratory of Biologically Active Compounds, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
| | - Martin Vagner
- Laboratory of Biologically Active Compounds, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
| | - Vaclav Motyka
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
- *Correspondence: Vaclav Motyka,
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23
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Zhou X, Zheng R, Liu G, Xu Y, Zhou Y, Laux T, Zhen Y, Harding SA, Shi J, Chen J. Desiccation Treatment and Endogenous IAA Levels Are Key Factors Influencing High Frequency Somatic Embryogenesis in Cunninghamia lanceolata (Lamb.) Hook. FRONTIERS IN PLANT SCIENCE 2017; 8:2054. [PMID: 29259612 PMCID: PMC5723420 DOI: 10.3389/fpls.2017.02054] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 11/16/2017] [Indexed: 05/12/2023]
Abstract
Cunninghamia lanceolata (Lamb.) Hook (Chinese fir) is an important tree, commercially and ecologically, in southern China. The traditional regenerating methods are based on organogenesis and cutting propagation. Here, we report the development of a high-frequency somatic embryogenesis (SE) regeneration system synchronized via a liquid culture from immature zygotic embryos. Following synchronization, PEM II cell aggregates were developmentally equivalent in appearance to cleaved zygotic embryos. Embryo and suspensor growth and subsequent occurrence of the apical and then the cotyledonary meristems were similar for zygotic and SE embryo development. However, SE proembryos exhibited a more reddish coloration than zygotic proembryos, and SE embryos were smaller than zygotic embryos. Mature somatic embryos gave rise to plantlets on hormone-free medium. For juvenile explants, low concentrations of endogenous indole-3-acetic acid in initial explants correlated with improved proembryogenic mass formation, and high SE competency. Analysis of karyotypes and microsatellites detected no major genetic variation in the plants regenerated via SE, and suggest a potential in the further development of this system as a reliable methodology for true-to-type seedling production. Treatment with polyethylene glycol (PEG) and abscisic acid (ABA) were of great importance to proembryo formation and complemented each other. ABA assisted the growth of embryonal masses, whereas PEG facilitated the organization of the proembryo-like structures. SOMATIC EMBRYOGENESIS RECEPTOR KINASE SERK) and the WUSCHEL homeobox (WOX) transcription factor served as molecular markers during early embryogenesis. Our results show that ClSERKs are conserved and redundantly expressed during SE. SERK and WOX transcript levels were highest during development of the proembryos and lowest in developed embryos. ClWOX13 expression correlates with the critical transition from proembryogenic masses to proembryos. Both SERK and WOX expression reveal their applicability in Chinese fir as markers of early embryogenesis. Overall, the findings provided evidence for the potential of this system in high fidelity Chinese fir seedlings production. Also, SE modification strategies were demonstrated and could be applied in other conifer species on the basis of our hormonal, morphological and molecular analyses.
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Affiliation(s)
- Xiaohong Zhou
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Renhua Zheng
- The Key Laboratory of Timber Forest Breeding and Cultivation for Mountainous Areas in Southern China, State Forestry Administration Engineering Research Center of Chinese Fir, Fujian Academy of Forestry, Fuzhou, China
| | - Guangxin Liu
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Yang Xu
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing, China
| | - Yanwei Zhou
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Thomas Laux
- Centre for Biological Signaling Studies, Faculty of Biology, Albert Ludwigs University of Freiburg, Freiburg, Germany
| | - Yan Zhen
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Scott A. Harding
- School of Forestry and Natural Resources, University of Georgia, Athens, GA, United States
| | - Jisen Shi
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Jinhui Chen
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, China
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24
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Liu Y, El-Kassaby YA. Global Analysis of Small RNA Dynamics during Seed Development of Picea glauca and Arabidopsis thaliana Populations Reveals Insights on their Evolutionary Trajectories. FRONTIERS IN PLANT SCIENCE 2017; 8:1719. [PMID: 29046688 PMCID: PMC5632664 DOI: 10.3389/fpls.2017.01719] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/20/2017] [Indexed: 06/07/2023]
Abstract
While DNA methylation carries genetic signals and is instrumental in the evolution of organismal complexity, small RNAs (sRNAs), ~18-24 ribonucleotide (nt) sequences, are crucial mediators of methylation as well as gene silencing. However, scant study deals with sRNA evolution via featuring their expression dynamics coupled with species of different evolutionary time. Here we report an atlas of sRNAs and microRNAs (miRNAs, single-stranded sRNAs) produced over time at seed-set of two major spermatophytes represented by populations of Picea glauca and Arabidopsis thaliana with different seed-set duration. We applied diverse profiling methods to examine sRNA and miRNA features, including size distribution, sequence conservation and reproduction-specific regulation, as well as to predict their putative targets. The top 27 most abundant miRNAs were highly overlapped between the two species (e.g., miR166,-319 and-396), but in P. glauca, they were less abundant and significantly less correlated with seed-set phases. The most abundant sRNAs in libraries were deeply conserved miRNAs in the plant kingdom for Arabidopsis but long sRNAs (24-nt) for P. glauca. We also found significant difference in normalized expression between populations for population-specific sRNAs but not for lineage-specific ones. Moreover, lineage-specific sRNAs were enriched in the 21-nt size class. This pattern is consistent in both species and alludes to a specific type of sRNAs (e.g., miRNA, tasiRNA) being selected for. In addition, we deemed 24 and 9 sRNAs in P. glauca and Arabidopsis, respectively, as sRNA candidates targeting known adaptive genes. Temperature had significant influence on selected gene and miRNA expression at seed development in both species. This study increases our integrated understanding of sRNA evolution and its potential link to genomic architecture (e.g., sRNA derivation from genome and sRNA-mediated genomic events) and organismal complexity (e.g., association between different sRNA expression and their functionality).
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Electrophoresis-Based Proteomics to Study Development and Germination of Date Palm Zygotic Embryos. Methods Mol Biol 2017. [PMID: 28755235 DOI: 10.1007/978-1-4939-7159-6_27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Proteomics has become an important and powerful tool in plant biology research. To establish a proteomic reference map of date palm zygotic embryos (ZE), we separated and identified proteins from zygotic embryos during different developmental and germination phases using one, two-dimensional polyacrylamide gel electrophoresis and mass spectrometry. Proteins are extracted with trichloroacetic acid (TCA)/acetone-phenol and resolved by gel electrophoresis. Gel images are captured and analyzed by appropriate software and statistical packages. Quantitative or qualitative variable bands or spots are subjected to MS analysis in order to identify them and correlate differences in the protein profiles with the different stages of date palm zygotic embryo development, maturation, and germination.
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Somatic Embryogenesis of Immature Cunninghamia lanceolata (Lamb.) Hook Zygotic Embryos. Sci Rep 2017; 7:56. [PMID: 28246394 PMCID: PMC5427901 DOI: 10.1038/s41598-017-00156-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 02/13/2017] [Indexed: 11/24/2022] Open
Abstract
Two efficient somatic embryogenesis systems were developed in Chinese fir, the most important conifer for industrial wood production in China. Three development stages (cleavage polyembryony, dominant embryo, and precotyledon) of immature embryos derived from 25 genotypes of open-pollinated mother trees were used as initial explants. Cleavage polyembryony-stage embryos with a 12.44% induction rate was the most embryogenic response stage. The highest frequency of embryogenic callus (13.86%) induction was obtained from DCR medium supplemented with 1.5 mg L−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.3 mg L−1 kinetin (KN). An average of 53.33 early somatic embryos were produced from approximately 0.2 g (fresh weight) embryogenic callus after 2 weeks of incubation on medium supplemented with 50 μmol L−1 abscisic acid (ABA) and 100 g L−1 polyethylene glycol (PEG) 6000. About 53% dominant embryos have an embryogenic response after a 6-week cultivation on medium supplemented with 1.0–2.0 mg L−1 benzyladenine (BA), 0.2 mg L−1 naphthylacetic acid (NAA) or 2,4-D, and 0.004 mg L−1 thidiazuron (TDZ). After three successive transfer cultures on medium supplemented with 1.5 mg L−1 BA, 0.2 mg L−1 NAA, and 0.004 mg L−1 TDZ, 4.49–16.51% of the embryos developed into somatic embryos.
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Volkova PY, Geras’kin SA, Kazakova EA. Radiation exposure in the remote period after the Chernobyl accident caused oxidative stress and genetic effects in Scots pine populations. Sci Rep 2017; 7:43009. [PMID: 28223696 PMCID: PMC5320440 DOI: 10.1038/srep43009] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 01/18/2017] [Indexed: 11/10/2022] Open
Abstract
Even 30 years after the Chernobyl accident, biological effects of irradiation are observed in the chronically exposed Scots pine populations. Chronic radiation exposure at dose rates above 50 mGy∙yr-1 caused oxidative stress and led to the increase of antioxidants concentrations in these populations. Genetic variability was examined for 6 enzymes and 14 enzymatic loci of 6 Scots pine populations. Dose rates over 10 mGy∙yr-1 caused the increased frequency of mutations and changes in genetic structure of Scots pine populations. However, the same dose rates had no effect on enzymatic activities. The results indicate that even relatively low dose rates of radiation can be considered as an ecological factor which should be taken into account for ecological management and radiation protection of biota species.
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Ingram GC. Dying to live: cell elimination as a developmental strategy in angiosperm seeds. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:785-796. [PMID: 27702990 DOI: 10.1093/jxb/erw364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The complete elimination of unwanted cells during development is a repeated theme in both multicellular animals and in plants. In plants, such events have been extensively studied and reviewed in terms of their molecular regulation, of marker genes and proteins expressed, and in terms of cellular changes associated with their progression. This review will take a slightly different view of developmental cell elimination and will concentrate specifically on the numerous elimination events that occur during ovule and seed development (here grouped together as seed development). It asks why this cell elimination occurs in specific seed tissues, in order to understand something about the commonalities underlying how seemingly disparate events are triggered and regulated. Finally, by placing the seed in its broader evolutionary context, the question of why cell elimination may have emerged as such a key component of the seed developmental toolbox will be considered.
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Affiliation(s)
- Gwyneth C Ingram
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, CNRS (UMR 5667), INRA (UMR 0879), UCB Lyon 1, Ecole Normale Supérieure de Lyon, F-69342 Lyon, France
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Merino I, Abrahamsson M, Sterck L, Craven-Bartle B, Canovas F, von Arnold S. Transcript profiling for early stages during embryo development in Scots pine. BMC PLANT BIOLOGY 2016; 16:255. [PMID: 27863470 PMCID: PMC5116219 DOI: 10.1186/s12870-016-0939-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/28/2016] [Indexed: 05/22/2023]
Abstract
BACKGROUND Characterization of the expression and function of genes regulating embryo development in conifers is interesting from an evolutionary point of view. However, our knowledge about the regulation of embryo development in conifers is limited. During early embryo development in Pinus species the proembyo goes through a cleavage process, named cleavage polyembryony, giving rise to four embryos. One of these embryos develops to a dominant embryo, which will develop further into a mature, cotyledonary embryo, while the other embryos, the subordinate embryos, are degraded. The main goal of this study has been to identify processes that might be important for regulating the cleavage process and for the development of a dominant embryo. RESULTS RNA samples from embryos and megagametophytes at four early developmental stages during seed development in Pinus sylvestris were subjected to high-throughput sequencing. A total of 6.6 million raw reads was generated, resulting in 121,938 transcripts, out of which 36.106 contained ORFs. 18,638 transcripts were differentially expressed (DETs) in embryos and megagametophytes. GO enrichment analysis of transcripts up-regulated in embryos showed enrichment for different cellular processes, while those up-regulated in megagametophytes were enriched for accumulation of storage material and responses to stress. The highest number of DETs was detected during the initiation of the cleavage process. Transcripts related to embryogenic competence, cell wall modifications, cell division pattern, axis specification and response to hormones and stress were highly abundant and differentially expressed during early embryo development. The abundance of representative DETs was confirmed by qRT-PCR analyses. CONCLUSION Based on the processes identified in the GO enrichment analyses and the expression of the selected transcripts we suggest that (i) processes related to embryogenic competence and cell wall loosening are involved in activating the cleavage process; (ii) apical-basal polarization is strictly regulated in dominant embryos but not in the subordinate embryos; (iii) the transition from the morphogenic phase to the maturation phase is not completed in subordinate embryos. This is the first genome-wide transcript expression profiling of the earliest stages during embryo development in a Pinus species. Our results can serve as a framework for future studies to reveal the functions of identified genes.
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Affiliation(s)
- Irene Merino
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Box 7080, 750 07 Uppsala, Sweden
| | - Malin Abrahamsson
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Box 7080, 750 07 Uppsala, Sweden
| | - Lieven Sterck
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Ghent, B-9000 Belgium
| | - Blanca Craven-Bartle
- Department of Molecular Biology and Biochemistry, School of Sciences, Campus de Teatinos, Universidad de Malaga, 29071 Malaga, Spain
| | - Francisco Canovas
- Department of Molecular Biology and Biochemistry, School of Sciences, Campus de Teatinos, Universidad de Malaga, 29071 Malaga, Spain
| | - Sara von Arnold
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Box 7080, 750 07 Uppsala, Sweden
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Trontin JF, Klimaszewska K, Morel A, Hargreaves C, Lelu-Walter MA. Molecular Aspects of Conifer Zygotic and Somatic Embryo Development: A Review of Genome-Wide Approaches and Recent Insights. Methods Mol Biol 2016; 1359:167-207. [PMID: 26619863 DOI: 10.1007/978-1-4939-3061-6_8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Genome-wide profiling (transcriptomics, proteomics, metabolomics) is providing unprecedented opportunities to unravel the complexity of coordinated gene expression during embryo development in trees, especially conifer species harboring "giga-genome." This knowledge should be critical for the efficient delivery of improved varieties through seeds and/or somatic embryos in fluctuating markets and to cope with climate change. We reviewed "omics" as well as targeted gene expression studies during both somatic and zygotic embryo development in conifers and tentatively puzzled over the critical processes and genes involved at the specific developmental and transition stages. Current limitations to the interpretation of these large datasets are going to be lifted through the ongoing development of comprehensive genome resources in conifers. Nevertheless omics already confirmed that master regulators (e.g., transcription and epigenetic factors) play central roles. As in model angiosperms, the molecular regulation from early to late embryogenesis may mainly arise from spatiotemporal modulation of auxin-, gibberellin-, and abscisic acid-mediated responses. Omics also showed the potential for the development of tools to assess the progress of embryo development or to build genotype-independent, predictive models of embryogenesis-specific characteristics.
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Affiliation(s)
- Jean-François Trontin
- FCBA, Pôle Biotechnologie et Sylviculture Avancée, Campus Forêt-Bois de Pierroton, 71 Route d'Arcachon, Cestas, 33610, France.
| | - Krystyna Klimaszewska
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du P.E.P.S., 10380, Stn. Sainte-Foy, QC, Canada, G1V 4C7
| | - Alexandre Morel
- INRA, UR 0588 Unité Amélioration, Génétique et Physiologie Forestières, 2163 Avenue de la Pomme de Pin, CS 4001, Ardon, Orléans Cedex 2, 45075, France
| | | | - Marie-Anne Lelu-Walter
- INRA, UR 0588 Unité Amélioration, Génétique et Physiologie Forestières, 2163 Avenue de la Pomme de Pin, CS 4001, Ardon, Orléans Cedex 2, 45075, France
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Wickramasuriya AM, Dunwell JM. Global scale transcriptome analysis of Arabidopsis embryogenesis in vitro. BMC Genomics 2015; 16:301. [PMID: 25887996 PMCID: PMC4404573 DOI: 10.1186/s12864-015-1504-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 03/30/2015] [Indexed: 11/25/2022] Open
Abstract
Background Somatic embryogenesis (SE) in plants is a process by which embryos are generated directly from somatic cells, rather than from the fused products of male and female gametes. Despite the detailed expression analysis of several somatic-to-embryonic marker genes, a comprehensive understanding of SE at a molecular level is still lacking. The present study was designed to generate high resolution transcriptome datasets for early SE providing the way for future research to understand the underlying molecular mechanisms that regulate this process. We sequenced Arabidopsis thaliana somatic embryos collected from three distinct developmental time-points (5, 10 and 15 d after in vitro culture) using the Illumina HiSeq 2000 platform. Results This study yielded a total of 426,001,826 sequence reads mapped to 26,520 genes in the A. thaliana reference genome. Analysis of embryonic cultures after 5 and 10 d showed differential expression of 1,195 genes; these included 778 genes that were more highly expressed after 5 d as compared to 10 d. Moreover, 1,718 genes were differentially expressed in embryonic cultures between 10 and 15 d. Our data also showed at least eight different expression patterns during early SE; the majority of genes are transcriptionally more active in embryos after 5 d. Comparison of transcriptomes derived from somatic embryos and leaf tissues revealed that at least 4,951 genes are transcriptionally more active in embryos than in the leaf; increased expression of genes involved in DNA cytosine methylation and histone deacetylation were noted in embryogenic tissues. In silico expression analysis based on microarray data found that approximately 5% of these genes are transcriptionally more active in somatic embryos than in actively dividing callus and non-dividing leaf tissues. Moreover, this identified 49 genes expressed at a higher level in somatic embryos than in other tissues. This included several genes with unknown function, as well as others related to oxidative and osmotic stress, and auxin signalling. Conclusions The transcriptome information provided here will form the foundation for future research on genetic and epigenetic control of plant embryogenesis at a molecular level. In follow-up studies, these data could be used to construct a regulatory network for SE; the genes more highly expressed in somatic embryos than in vegetative tissues can be considered as potential candidates to validate these networks. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1504-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Jim M Dunwell
- School of Agriculture, Policy and Development, University of Reading, Reading, UK.
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Pullman GS, Zeng X, Copeland-Kamp B, Crockett J, Lucrezi J, May SW, Bucalo K. Conifer somatic embryogenesis: improvements by supplementation of medium with oxidation-reduction agents. TREE PHYSIOLOGY 2015; 35:209-24. [PMID: 25716878 DOI: 10.1093/treephys/tpu117] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A major barrier to the commercialization of somatic embryogenesis technology in loblolly pine (Pinus taeda L.) is recalcitrance of some high-value crosses to initiate embryogenic tissue (ET) and continue early-stage somatic embryo growth. Developing initiation and multiplication media that resemble the seed environment has been shown to decrease this recalcitrance. Glutathione (GSH), glutathione disulfide (GSSG), ascorbic acid and dehydroascorbate analyses were performed weekly throughout the sequence of seed development for female gametophyte and zygotic embryo tissues to determine physiological concentrations. Major differences in stage-specific oxidation-reduction (redox) agents were observed. A simple bioassay was used to evaluate potential growth-promotion of natural and inorganic redox agents added to early-stage somatic embryo growth medium. Compounds showing statistically significant increases in early-stage embryo growth were then tested for the ability to increase initiation of loblolly pine. Low-cost reducing agents sodium dithionite and sodium thiosulfate increased ET initiation for loblolly pine and Douglas fir (Mirb) Franco. Germination medium supplementation with GSSG increased somatic embryo germination. Early-stage somatic embryos grown on medium with or without sodium thiosulfate did not differ in GSH or GSSG content, suggesting that sodium thiosulfate-mediated growth stimulation does not involve GSH or GSSG. We have developed information demonstrating that alteration of the redox environment in vitro can improve ET initiation, early-stage embryo development and somatic embryo germination in loblolly pine.
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Affiliation(s)
- Gerald S Pullman
- School of Biology, Georgia Institute of Technology, 500 10th Street N.W., Atlanta, GA 30332-0620, USA Renewable Bioproducts Institute (RBI), Georgia Institute of Technology, 500 10th Street N.W., Atlanta, GA 30332-0620, USA
| | - Xiaoyan Zeng
- Renewable Bioproducts Institute (RBI), Georgia Institute of Technology, 500 10th Street N.W., Atlanta, GA 30332-0620, USA
| | - Brandi Copeland-Kamp
- Renewable Bioproducts Institute (RBI), Georgia Institute of Technology, 500 10th Street N.W., Atlanta, GA 30332-0620, USA
| | - Jonathan Crockett
- Renewable Bioproducts Institute (RBI), Georgia Institute of Technology, 500 10th Street N.W., Atlanta, GA 30332-0620, USA
| | - Jacob Lucrezi
- School of Chemistry and Biochemistry, Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Sheldon W May
- School of Chemistry and Biochemistry, Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Kylie Bucalo
- Renewable Bioproducts Institute (RBI), Georgia Institute of Technology, 500 10th Street N.W., Atlanta, GA 30332-0620, USA
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Morel A, Trontin JF, Corbineau F, Lomenech AM, Beaufour M, Reymond I, Le Metté C, Ader K, Harvengt L, Cadene M, Label P, Teyssier C, Lelu-Walter MA. Cotyledonary somatic embryos of Pinus pinaster Ait. most closely resemble fresh, maturing cotyledonary zygotic embryos: biological, carbohydrate and proteomic analyses. PLANTA 2014; 240:1075-95. [PMID: 25115559 DOI: 10.1007/s00425-014-2125-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 07/07/2014] [Indexed: 05/22/2023]
Abstract
Cotyledonary somatic embryos (SEs) of maritime pine are routinely matured for 12 weeks before being germinated and converted to plantlets. Although regeneration success is highly dependent on SEs quality, the date of harvesting is currently determined mainly on the basis of morphological features. This empirical method does not provide any accurate information about embryo quality with respect to storage compounds (proteins, carbohydrates). We first analyzed SEs matured for 10, 12 and 14 weeks by carrying out biological (dry weight, water content) and biochemical measurements (total protein and carbohydrate contents). No difference could be found between collection dates, suggesting that harvesting SEs after 12 weeks is appropriate. Cotyledonary SEs were then compared to various stages, from fresh to fully desiccated, in the development of cotyledonary zygotic embryos (ZEs). We identified profiles that were similar using hierarchical ascendant cluster analysis (HCA). Fresh and dehydrated ZEs could be distinguished, and SEs clustered with fresh ZEs. Both types of embryo exhibited similar carbohydrate and protein contents and signatures. This high level of similarity (94.5 %) was further supported by proteome profiling. Highly expressed proteins included storage, stress-related, late embryogenesis abundant and energy metabolism proteins. By comparing overexpressed proteins in developing and cotyledonary SEs or ZEs, some (23 proteins) could be identified as candidate biomarkers for the late, cotyledonary stage. This is the first report of useful generic protein markers for monitoring embryo development in maritime pine. Our results also suggest that improvements of SEs quality may be achieved if the current maturation conditions are refined.
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Affiliation(s)
- Alexandre Morel
- INRA, UR 0588 Unité Amélioration, Génétique et Physiologie Forestières, 2163 Avenue de la Pomme de Pin, CS 4001, Ardon, 45075, Orléans Cedex 2, France
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Geras'kin SA, Volkova PY. Genetic diversity in Scots pine populations along a radiation exposure gradient. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 496:317-327. [PMID: 25087063 DOI: 10.1016/j.scitotenv.2014.07.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 07/05/2014] [Accepted: 07/05/2014] [Indexed: 06/03/2023]
Abstract
Polymorphisms of antioxidant enzymes were studied in the endosperm and embryos of seeds from Scots pine populations inhabiting sites in the Bryansk region of Russia radioactively contaminated as a result of the Chernobyl accident. Chronic radiation exposure at dose rates from 0.8 μGy/h led to a significant increase in the rate of enzymatic loci mutations. The main parameters of genetic variability of the affected Scots pine populations had considerably higher values than those from the reference site. Changes in the genetic makeup of Scots pine populations were observed at dose rates greater than 10.4 μGy/h. However, the higher mutation rate had no effect on the activities of antioxidant enzymes.
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Affiliation(s)
- Stanislav A Geras'kin
- Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, 109km, 249032 Obninsk, Russia.
| | - Polina Yu Volkova
- Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, 109km, 249032 Obninsk, Russia
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Morel A, Teyssier C, Trontin JF, Eliášová K, Pešek B, Beaufour M, Morabito D, Boizot N, Le Metté C, Belal-Bessai L, Reymond I, Harvengt L, Cadene M, Corbineau F, Vágner M, Label P, Lelu-Walter MA. Early molecular events involved in Pinus pinaster Ait. somatic embryo development under reduced water availability: transcriptomic and proteomic analyses. PHYSIOLOGIA PLANTARUM 2014; 152:184-201. [PMID: 24460664 DOI: 10.1111/ppl.12158] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/19/2013] [Accepted: 12/20/2013] [Indexed: 05/22/2023]
Abstract
Maritime pine somatic embryos (SEs) require a reduction in water availability (high gellan gum concentration in the maturation medium) to reach the cotyledonary stage. This key switch, reported specifically for pine species, is not yet well understood. To facilitate the use of somatic embryogenesis for mass propagation of conifers, we need a better understanding of embryo development. Comparison of both transcriptome (Illumina RNA sequencing) and proteome [two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis with mass spectrometry (MS) identification] of immature SEs, cultured on either high (9G) or low (4G) gellan gum concentration, was performed, together with analysis of water content, fresh and dry mass, endogenous abscisic acid (ABA; gas chromatography-MS), soluble sugars (high-pressure liquid chromatography), starch and confocal laser microscope observations. This multiscale, integrated analysis was used to unravel early molecular and physiological events involved in SE development. Under unfavorable conditions (4G), the glycolytic pathway was enhanced, possibly in relation to cell proliferation that may be antagonistic to SE development. Under favorable conditions (9G), SEs adapted to culture constraint by activating specific protective pathways, and ABA-mediated molecular and physiological responses promoting embryo development. Our results suggest that on 9G, germin-like protein and ubiquitin-protein ligase could be used as predictive markers of SE development, whereas protein phosphatase 2C could be a biomarker for culture adaptive responses. This is the first characterization of early molecular mechanisms involved in the development of pine SEs following an increase in gellan gum concentration in the maturation medium, and it is also the first report on somatic embryogenesis in conifers combining transcriptomic and proteomic datasets.
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Affiliation(s)
- Alexandre Morel
- INRA, UR 0588 Unité Amélioration, Génétique et Physiologie Forestières, 2163 Avenue de la Pomme de Pin, CS 4001, Ardon, F-45075 Orléans Cedex 2, France
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Guo A, Zheng CX, Yang YY. Differential expression of SLOW WALKER2 homologue in ovules of female sterile mutant and fertile clone of Pinus tabulaeformis. Russ J Dev Biol 2014. [DOI: 10.1134/s1062360414020052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Zhang J, Zhang S, Han S, Li X, Tong Z, Qi L. Deciphering small noncoding RNAs during the transition from dormant embryo to germinated embryo in Larches (Larix leptolepis). PLoS One 2013; 8:e81452. [PMID: 24339932 PMCID: PMC3858266 DOI: 10.1371/journal.pone.0081452] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 10/11/2013] [Indexed: 11/25/2022] Open
Abstract
Small RNAs (sRNAs), as a key component of molecular biology, play essential roles in plant development, hormone signaling, and stress response. However, little is known about the relationships among sRNAs, hormone signaling, and dormancy regulation in gymnosperm embryos. To investigate the roles of sRNAs in embryo dormancy maintenance and release in Larix leptolepis, we deciphered the endogenous “sRNAome” in dormant and germinated embryos. High-throughput sequencing of sRNA libraries showed that dormant embryos exhibited a length bias toward 24-nt while germinated embryos showed a bias toward 21-nt lengths. This might be associated with distinct levels of RNA-dependent RNA polymerase2 (RDR2) and/or RDR6, which is regulated by hormones. Proportions of miRNAs to nonredundant and redundant sRNAs were higher in germinated embryos than in dormant embryos, while the ratio of unknown sRNAs was higher in dormant embryos than in germinated embryos. We identified a total of 160 conserved miRNAs from 38 families, 3 novel miRNAs, and 16 plausible miRNA candidates, of which many were upregulated in germinated embryos relative to dormant embryos. These findings indicate that larches and possibly other gymnosperms have complex mechanisms of gene regulation involving miRNAs and other sRNAs operating transcriptionally and posttranscriptionally during embryo dormancy and germination. We propose that abscisic acid modulates embryo dormancy and germination at least in part through regulation of the expression level of sRNA-biogenesis genes, thus changing the sRNA components.
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Affiliation(s)
- Junhong Zhang
- Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and Forestry University, Lin’an, Hangzhou, Zhejiang, P.R. China
- Laboratory of Cell Biology, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, P.R. China
| | - Shougong Zhang
- Laboratory of Cell Biology, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, P.R. China
| | - Suying Han
- Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, P.R. China
| | - Xinmin Li
- Laboratory of Cell Biology, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, P.R. China
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Zaikang Tong
- Nurturing Station for the State Key Laboratory of Subtropical Silviculture, Zhejiang Agriculture and Forestry University, Lin’an, Hangzhou, Zhejiang, P.R. China
- * E-mail: (ZT); (LQ)
| | - Liwang Qi
- Laboratory of Cell Biology, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, P.R. China
- * E-mail: (ZT); (LQ)
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Krajnáková J, Bertolini A, Zoratti L, Gömöry D, Häggman H, Vianello A. Changes in ATP, glucose-6-phosphate and NAD(P)H cellular levels during the proliferation and maturation phases of Abies alba Mill. embryogenic cultures. TREE PHYSIOLOGY 2013; 33:1099-110. [PMID: 24200583 DOI: 10.1093/treephys/tpt082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The aim of the present study was to evaluate the adenosine triphospate (ATP), glucose-6-phosphate (glu-6P) and reduced form of nicotinamide adenine dinucleotide phosphate (NAD(P)H) cellular levels during the proliferation and maturation phases of Abies alba Mill. somatic embryos. For a better understanding of the dynamics of these parameters during the proliferation cycle, four embryonic cell lines were tested. During the maturation period, three independent experiments were conducted, focused on the effects of PEG-4000 (5 or 10% (w/v)) and abscisic acid (16, 32 or 64 μM) applied together (Experiments A and B) or with addition of gibberellic acid (Experiment C) on the dynamics of bio-energetic molecules and on the mean number of cotyledonary somatic embryos. Our results demonstrated that the cellular levels of bio-energetic molecules strongly depended on the composition of maturation media. Generally, the higher the number of cotyledonary embryos produced, the higher the level of ATP observed after a 2-week maturation period. The cellular level of ATP, glu-6P and NAD(P)H increased, particularly after the transition from the proliferation to the maturation phase when the differentiation and growth of somatic embryos occurred.
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Affiliation(s)
- Jana Krajnáková
- Faculty of Forestry and Wood Technology, Mendel University, Zemědělská 3, 613 00 Czech Republic
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Xu Z, Zhang C, Zhang X, Liu C, Wu Z, Yang Z, Zhou K, Yang X, Li F. Transcriptome profiling reveals auxin and cytokinin regulating somatic embryogenesis in different sister lines of cotton cultivar CCRI24. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2013; 55:631-42. [PMID: 23710882 DOI: 10.1111/jipb.12073] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 05/15/2013] [Indexed: 05/22/2023]
Abstract
To get a broader view on the molecular mechanisms underlying somatic embryogenesis (SE) in cotton (Gossypium hirsutum L.), global analysis of cotton transcriptome dynamics during SE in different sister lines was performed using RNA-Seq. A total of 204 349 unigenes were detected by de novo assembly of the 214 977 462 Illumina reads. The quantitative reverse transcription-polymerase chain reaction (qRT-PCR) measurements were positively correlated with the RNA-Seq results for almost all the tested genes (R(2) = 0.841, correlation was significant at the 0.01 level). Different phytohormone (auxin and cytokinin) concentration ratios in medium and the endogenous content changes of these two phytohormones at two stages in different sister lines suggested the roles of auxin and cytokinin during cotton SE. On the basis of global gene regulation of phytohormone-related genes, numerous genes from all the differentially expressed transcripts were involved in auxin and cytokinin biosynthesis and signal transduction pathways. Analyses of differentially expressed genes that were involved in these pathways revealed the substantial changes in gene type and abundance between two sister lines. Isolation, cloning and silencing/overexpressing the genes that revealed remarkable up- or down-expression during cotton SE were important. Furthermore, auxin and cytokinin play a primary role in SE, but potential cross-talk with each other or other factors remains unclear.
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Affiliation(s)
- Zhenzhen Xu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agriculture Sciences, Anyang, 455000, China
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Raherison E, Rigault P, Caron S, Poulin PL, Boyle B, Verta JP, Giguère I, Bomal C, Bohlmann J, MacKay J. Transcriptome profiling in conifers and the PiceaGenExpress database show patterns of diversification within gene families and interspecific conservation in vascular gene expression. BMC Genomics 2012; 13:434. [PMID: 22931377 PMCID: PMC3534630 DOI: 10.1186/1471-2164-13-434] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 07/11/2012] [Indexed: 12/22/2022] Open
Abstract
Background Conifers have very large genomes (13 to 30 Gigabases) that are mostly uncharacterized although extensive cDNA resources have recently become available. This report presents a global overview of transcriptome variation in a conifer tree and documents conservation and diversity of gene expression patterns among major vegetative tissues. Results An oligonucleotide microarray was developed from Picea glauca and P. sitchensis cDNA datasets. It represents 23,853 unique genes and was shown to be suitable for transcriptome profiling in several species. A comparison of secondary xylem and phelloderm tissues showed that preferential expression in these vascular tissues was highly conserved among Picea spp. RNA-Sequencing strongly confirmed tissue preferential expression and provided a robust validation of the microarray design. A small database of transcription profiles called PiceaGenExpress was developed from over 150 hybridizations spanning eight major tissue types. In total, transcripts were detected for 92% of the genes on the microarray, in at least one tissue. Non-annotated genes were predominantly expressed at low levels in fewer tissues than genes of known or predicted function. Diversity of expression within gene families may be rapidly assessed from PiceaGenExpress. In conifer trees, dehydrins and late embryogenesis abundant (LEA) osmotic regulation proteins occur in large gene families compared to angiosperms. Strong contrasts and low diversity was observed in the dehydrin family, while diverse patterns suggested a greater degree of diversification among LEAs. Conclusion Together, the oligonucleotide microarray and the PiceaGenExpress database represent the first resource of this kind for gymnosperm plants. The spruce transcriptome analysis reported here is expected to accelerate genetic studies in the large and important group comprised of conifer trees.
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Affiliation(s)
- Elie Raherison
- Center for Forest Research and Institute for Integrative and Systems Biology, Université Laval, Québec, QC, Canada, G1V 0A6
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Zhang J, Zhang S, Han S, Wu T, Li X, Li W, Qi L. Genome-wide identification of microRNAs in larch and stage-specific modulation of 11 conserved microRNAs and their targets during somatic embryogenesis. PLANTA 2012; 236:647-57. [PMID: 22526500 DOI: 10.1007/s00425-012-1643-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 03/28/2012] [Indexed: 05/02/2023]
Abstract
MicroRNAs (miRNAs) are emerging as essential regulators of biological processes. Somatic embryogenesis is one of the most important techniques for gymnosperm-breeding programs, but there is little understanding of its underlying mechanism. To investigate the roles of miRNAs during somatic embryogenesis in larch, we constructed a small RNA library from somatic embryos. High-throughput sequencing of the library identified 83 conserved miRNAs from 35 families, 16 novel miRNAs, and 14 plausible miRNA candidates, with a high proportion specific to larch or gymnosperms. qRT-PCR analysis demonstrated that both the conserved and novel or candidate miRNAs were expressed in larch. Several miRNA precursor sequences were obtained via RACE. We predicted 110 target genes using bioinformatics, and validated 9 of them by 5' RACE. 11 conserved miRNA families including 17 miRNAs with critical functions in plant development and six target mRNAs were detected by qRT-PCR in the larch SE. Stage-specific expression of miRNAs and their targets indicate their possible modulation on SE of larch: miR171a/b might exert function on PEMs, while miR171c acts in the induction process of larch SE; miR397 and miR398 mainly involved in modulation of PEM propagation and transition to single embryo; miR162 and miR168 exert their regulatory function during total SE process, especially during stages 5-8; miR156, miR159, miR160, miR166, miR167, and miR390 might play regulatory roles during cotyledonary embryo development. These findings indicate that larch and possibly other gymnosperms have complex mechanisms of gene regulation involving specific and common miRNAs operating post-transcriptionally during embryogenesis.
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Affiliation(s)
- Junhong Zhang
- Laboratory of Cell Biology, Research Institute of Forestry, Chinese Academy of Forestry, Xiangshan Road, Beijing, 100091, China.
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Zhen Y, Zhao ZZ, Zheng RH, Shi J. Proteomic analysis of early seed development in Pinus massoniana L. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2012; 54:97-104. [PMID: 22391127 DOI: 10.1016/j.plaphy.2012.02.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 02/06/2012] [Indexed: 05/13/2023]
Abstract
Understanding seed development is important for large-scale propagation and germplasm conservation for the Masson pine. We undertook a proteomic analysis of Masson pine seeds during the early stages of embryogenesis. Two-dimensional difference gel electrophoresis (2D DIGE) was used to quantify the differences in protein expression during early seed development. Using electrospray ionization mass spectrometry/mass spectrometry, we identified proteins from 43 gel spots that had been excised from preparative "pick" gels. Proteins involved in carbon metabolism were identified and were predominantly expressed at higher levels during the cleavage polyembryony and columnar embryo stages. Functional annotation of one seed protein revealed it involvement in programmed cell death and translation of selective mRNAs, which may play an important role in subordinate embryo elimination and suspensor degeneration in polyembryonic seed gymnosperms. Other identified proteins were associated with protein folding, nitrogen metabolism, disease/defense response, and protein storage, synthesis and stabilization. The comprehensive protein expression profiles generated by this study will provide new insights into the complex developmental process of seed development in Masson pine.
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Affiliation(s)
- Yan Zhen
- Key Laboratory of Forest Genetics and Biotechnology, Nanjing Forestry University, Ministry of Education, Nanjing 210037, People's Republic of China
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Schlögl PS, Dos Santos ALW, Vieira LDN, Floh EIS, Guerra MP. Cloning and expression of embryogenesis-regulating genes in Araucaria angustifolia (Bert.) O. Kuntze (Brazilian Pine). Genet Mol Biol 2012; 35:172-81. [PMID: 22481892 PMCID: PMC3313508 DOI: 10.1590/s1415-47572012005000005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Accepted: 08/27/2011] [Indexed: 11/22/2022] Open
Abstract
Angiosperm and gymnosperm plants evolved from a common ancestor about 300 million years ago. Apart from morphological and structural differences in embryogenesis and seed origin, a set of embryogenesis-regulating genes and the molecular mechanisms involved in embryo development seem to have been conserved alike in both taxa. Few studies have covered molecular aspects of embryogenesis in the Brazilian pine, the only economically important native conifer in Brazil. Thus eight embryogenesis-regulating genes, viz., ARGONAUTE 1, CUP-SHAPED COTYLEDON 1, WUSCHEL-related WOX, S-LOCUS LECTIN PROTEIN KINASE, SCARECROW-like, VICILIN 7S, LEAFY COTYLEDON 1, and REVERSIBLE GLYCOSYLATED POLYPEPTIDE 1, were analyzed through semi-quantitative RT-PCR during embryo development and germination. All the eight were found to be differentially expressed in the various developmental stages of zygotic embryos, seeds and seedling tissues. To our knowledge, this is the first report on embryogenesis-regulating gene expression in members of the Araucariaceae family, as well as in plants with recalcitrant seeds.
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Affiliation(s)
- Paulo Sérgio Schlögl
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Departamento de Fitotecnia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
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Uddenberg D, Valladares S, Abrahamsson M, Sundström JF, Sundås-Larsson A, von Arnold S. Embryogenic potential and expression of embryogenesis-related genes in conifers are affected by treatment with a histone deacetylase inhibitor. PLANTA 2011; 234:527-39. [PMID: 21541665 PMCID: PMC3162143 DOI: 10.1007/s00425-011-1418-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 04/12/2011] [Indexed: 05/06/2023]
Abstract
Somatic embryogenesis is used for vegetative propagation of conifers. Embryogenic cultures can be established from zygotic embryos; however, the embryogenic potential decreases during germination. In Arabidopsis, LEAFY COTYLEDON (LEC) genes are expressed during the embryonic stage, and must be repressed to allow germination. Treatment with the histone deacetylase inhibitor trichostatin A (TSA) causes de-repression of LEC genes. ABSCISIC ACID3 (ABI3) and its Zea mays ortholog VIVIPAROUS1 (VP1) act together with the LEC genes to promote embryo maturation. In this study, we have asked the question whether TSA treatment in a conifer affects the embryogenic potential and the expression of embryogenesis-related genes. We isolated two conifer LEC1-type HAP3 genes, HAP3A and HAP3B, from Picea abies and Pinus sylvestris. A comparative phylogenetic analysis of plant HAP3 genes suggests that HAP3A and HAP3B are paralogous genes originating from a duplication event in the conifer lineage. The expression of HAP3A is high, in both somatic and zygotic embryos, during early embryo development, but decreases during late embryogeny. In contrast, the expression of VP1 is initially low but increases during late embryogeny. After exposure to TSA, germinating somatic embryos of P. abies maintain the competence to differentiate embryogenic tissue, and simultaneously the germination progression is partially inhibited. Furthermore, when embryogenic cultures of P. abies are exposed to TSA during embryo maturation, the maturation process is arrested and the expression levels of PaHAP3A and PaVP1 are maintained, suggesting a possible link between chromatin structure and expression of embryogenesis-related genes in conifers.
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Affiliation(s)
- Daniel Uddenberg
- Uppsala Biocenter, Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences (SLU), 7080, 75007 Uppsala, Sweden.
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Geras'kin S, Oudalova A, Dikareva N, Spiridonov S, Hinton T, Chernonog E, Garnier-Laplace J. Effects of radioactive contamination on Scots pines in the remote period after the Chernobyl accident. ECOTOXICOLOGY (LONDON, ENGLAND) 2011; 20:1195-208. [PMID: 21451948 DOI: 10.1007/s10646-011-0664-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/21/2011] [Indexed: 05/24/2023]
Abstract
A 6 year study of Scots pine populations inhabiting sites in the Bryansk region of Russia radioactively contaminated as a result of the Chernobyl accident is presented. In six study sites, (137)Cs activity concentrations and heavy metal content in soils, as well as (137)Cs, (90)Sr and heavy metal concentrations in cones were measured. Doses absorbed in reproduction organs of pine trees were calculated using a dosimetric model. The maximum annual dose absorbed at the most contaminated site was about 130 mGy. Occurrence of aberrant cells scored in the root meristem of germinated seeds collected from pine trees growing on radioactively contaminated territories for over 20 years significantly exceeded the reference levels during all 6 years of the study. The data suggest that cytogenetic effects occur in Scots pine populations due to the radioactive contamination. However, no consistent differences in reproductive ability were detected between the impacted and reference populations as measured by the frequency of abortive seeds. Even though the Scots pine populations have occupied radioactively contaminated territories for two decades, there were no clear indications of adaptation to the radiation, when measured by the number of aberrant cells in root meristems of seeds exposed to an additional acute dose of radiation.
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Affiliation(s)
- Stanislav Geras'kin
- Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, 109 km, 249032, Obninsk, Russia.
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Jeong S, Bayer M, Lukowitz W. Taking the very first steps: from polarity to axial domains in the early Arabidopsis embryo. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:1687-97. [PMID: 21172809 DOI: 10.1093/jxb/erq398] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Arabidopsis embryos follow a predictable sequence of cell divisions, facilitating a genetic analysis of their early development. Both asymmetric divisions and cell-to-cell communication are probably involved in generating specific gene expression domains along the main axis within the first few division cycles. The function of these domains is not always understood, but recent work suggests that they may serve as a basis for organizing polar auxin flux. Auxin acts as systemic signal throughout the life cycle and, in the embryo, has been demonstrated to direct formation of the main axis and root initiation at the globular stage. At about the same time, root versus shoot fates are imposed on the incipient meristems by the expression of antagonistic regulators at opposite poles of the embryo. Some of the key features of the embryonic patterning process have emerged over the past few years and may provide the elements of a coherent conceptual framework.
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Affiliation(s)
- Sangho Jeong
- Department of Plant Biology, University of Georgia, Athens, GA 30602-7271, USA
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Agarwal P, Kapoor S, Tyagi AK. Transcription factors regulating the progression of monocot and dicot seed development. Bioessays 2011; 33:189-202. [PMID: 21319185 DOI: 10.1002/bies.201000107] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Seed development in this paper has been classified into the three landmark stages of cell division, organ initiation and maturation, based on morphological changes, and the available literature. The entire process proceeds at the behest of an interplay of various specific and general transcription factors (TFs). Monocots and dicots utilize overlapping, as well as distinct, TF networks during the process of seed development. The known TFs in rice and Arabidopsis have been chronologically categorized into the three stages. The main regulators of seed development contain B3 or HAP3 domains. These interact with bZIP and AP2 TFs. Other TFs that play an indispensable role during the process contain homeobox-, NAC-, MYB-, or ARF-domains. This paper is a comprehensive analysis of the TFs essential for seed development and their interactions. An understanding of this interplay will not only help unravel an integrated developmental process, but will also pave the way for biotechnological applications.
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Affiliation(s)
- Pinky Agarwal
- Interdisciplinary Centre for Plant Genomics, Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
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Abstract
Somatic embryogenesis (SE) has the potential to be the lowest-cost method to rapidly produce large numbers of high-value somatic seedlings with desired characteristics for plantation forestry. At least 24 of the 115-120 known Pinus species can undergo SE. Initiation for most species works best with immature megagametophytes as starting material, although a few pines can initiate SE cultures from isolated mature seed embryos. Successful initiation depends heavily on explant type, embryo developmental stage, and medium salt base. Most first reports of initiation used 2,4-D and BAP or a combination of cytokinins. More recent reports have optimized initiation for many Pinus spp., but still use mostly the combinations of auxin and cytokinins. Initiation can be stimulated with medium supplements including abscisic acid (ABA), brassinosteroids, ethylene inhibitors, gibberellin inhibitors, organic acids, putrescine, specific sugar types (maltose, galactose, D-chiro-inositol, and D-xylose), triacontanol, vitamins (B12, biotin, vitamin E, and folic acid), or manipulation of environmental factors including pH, water potential, cone cold storage, gelling agent concentration, and liquid medium. Embryo development and maturation usually occur best on medium containing ABA along with water potential reduction (with sugars and polyethylene glycol) or water availability reduction (with raised gelling agent increasing gel-strength). Activated carbon and maltose may also improve embryo maturation. The main issues holding SE technology back are related to the high cost of producing a somatic seedling, incurred from low initiation percentages for recalcitrant species, culture loss, and decline after initiation and poor embryo maturation resulting in no or poor germination. Although vast progress has been made in pine SE technology over the past 24 years, fundamental studies on seed and embryo physiology, biochemistry, and gene expression are still needed to help improve the technology to a point where large-scale commercialization is economically viable for a broad range of pine species.
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Affiliation(s)
- Gerald S Pullman
- School of Biology and Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA, USA.
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Palovaara J, Hallberg H, Stasolla C, Hakman I. Comparative expression pattern analysis of WUSCHEL-related homeobox 2 (WOX2) and WOX8/9 in developing seeds and somatic embryos of the gymnosperm Picea abies. THE NEW PHYTOLOGIST 2010; 188:122-35. [PMID: 20561212 DOI: 10.1111/j.1469-8137.2010.03336.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
• In seed plants, current knowledge concerning embryonic pattern formation by polar auxin transport (PAT) and WUSCHEL-related homeobox (WOX) gene activity is primarily derived from studies on angiosperms, while less is known about these processes in gymnosperms. In view of the differences in their embryogeny, and the fact that somatic embryogenesis is used for mass propagation of conifers, a better understanding of embryo development is vital. • The expression patterns of PaWOX2 and PaWOX8/9 were followed with quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and in situ hybridization (ISH) during seed and somatic embryo development in Norway spruce (Picea abies), and in somatic embryos treated with the PAT inhibitor N-1-naphthylphthalamic acid (NPA). • Both PaWOX2 and PaWOX8/9 were highly expressed at the early growth stages of zygotic and somatic embryos, and shared a similar expression pattern over the entire embryo. At later embryo stages, high expression of PaWOX8/9 became restricted to cotyledon primordia, epidermis, procambium and root apical meristem (RAM), which became most evident in NPA-treated somatic embryos, while expression of PaWOX2 was much lower. • Our results suggest an ancestral role of WOX in seed plant embryo development, and strengthen the proposed connection between PAT, PIN-FORMED (PIN) and WOX in the regulation of embryo patterning in seed plants.
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Affiliation(s)
- Joakim Palovaara
- School of Natural Sciences, Linnaeus University, SE-391 82 Kalmar, Sweden
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Shi J, Zhen Y, Zheng RH. Proteome profiling of early seed development in Cunninghamia lanceolata (Lamb.) Hook. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:2367-81. [PMID: 20363864 PMCID: PMC2877891 DOI: 10.1093/jxb/erq066] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 03/03/2010] [Accepted: 03/03/2010] [Indexed: 05/06/2023]
Abstract
Knowledge of the proteome of the early gymnosperm embryo could provide important information for optimizing plant cloning procedures and for establishing platforms for research into plant development/regulation and in vitro transgenic studies. Compared with angiosperms, it is more difficult to induce somatic embryogenesis in gymnosperms; success in this endeavour could be increased, however, if proteomic information was available on the complex, dynamic, and multistage processes of gymnosperm embryogenesis in vivo. A proteomic analysis of Chinese fir seeds in six developmental stages was carried out during early embryogenesis. Proteins were extracted from seeds dissected from immature cones and separated by two-dimensional difference gel electrophoresis. Analysis with DeCyder 6.5 software revealed 136 spots that differed in kinetics of appearance. Analysis by liquid chromatography coupled to tandem mass spectrometry and MALDI-TOF mass spectrometry identified proteins represented by 71 of the spots. Functional annotation of these seed proteins revealed their involvement in programmed cell death and chromatin modification, indicating that the proteins may play a central role in determining the number of zygotic embryos generated and controlling embryo patterning and shape remodelling. The analysis also revealed other proteins involved in carbon metabolism, methionine metabolism, energy production, protein storage, synthesis and stabilization, disease/defence, the cytoskeleton, and embryo development. The comprehensive protein expression profiles generated by our study provide new insights into the complex developmental processes in the seeds of the Chinese fir.
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Affiliation(s)
- Jisen Shi
- Key Laboratory of Forest Genetics and Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, China.
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