1
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Romani F, Sauret-Güeto S, Rebmann M, Annese D, Bonter I, Tomaselli M, Dierschke T, Delmans M, Frangedakis E, Silvestri L, Rever J, Bowman JL, Romani I, Haseloff J. The landscape of transcription factor promoter activity during vegetative development in Marchantia. THE PLANT CELL 2024; 36:2140-2159. [PMID: 38391349 PMCID: PMC11132968 DOI: 10.1093/plcell/koae053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 12/08/2023] [Accepted: 12/22/2023] [Indexed: 02/24/2024]
Abstract
Transcription factors (TFs) are essential for the regulation of gene expression and cell fate determination. Characterizing the transcriptional activity of TF genes in space and time is a critical step toward understanding complex biological systems. The vegetative gametophyte meristems of bryophytes share some characteristics with the shoot apical meristems of flowering plants. However, the identity and expression profiles of TFs associated with gametophyte organization are largely unknown. With only ∼450 putative TF genes, Marchantia (Marchantia polymorpha) is an outstanding model system for plant systems biology. We have generated a near-complete collection of promoter elements derived from Marchantia TF genes. We experimentally tested reporter fusions for all the TF promoters in the collection and systematically analyzed expression patterns in Marchantia gemmae. This allowed us to build a map of expression domains in early vegetative development and identify a set of TF-derived promoters that are active in the stem-cell zone. The cell markers provide additional tools and insight into the dynamic regulation of the gametophytic meristem and its evolution. In addition, we provide an online database of expression patterns for all promoters in the collection. We expect that these promoter elements will be useful for cell-type-specific expression, synthetic biology applications, and functional genomics.
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Affiliation(s)
- Facundo Romani
- Department of Plant Sciences, University of Cambridge, Cambridge CB3 EA, UK
| | | | - Marius Rebmann
- Department of Plant Sciences, University of Cambridge, Cambridge CB3 EA, UK
| | - Davide Annese
- Department of Plant Sciences, University of Cambridge, Cambridge CB3 EA, UK
| | - Ignacy Bonter
- Department of Plant Sciences, University of Cambridge, Cambridge CB3 EA, UK
| | - Marta Tomaselli
- Department of Plant Sciences, University of Cambridge, Cambridge CB3 EA, UK
| | - Tom Dierschke
- School of Biological Sciences, Monash University, Clayton, Melbourne, VIC 3800, Australia
- ARC Centre of Excellence for Plant Success in Nature and Agriculture, Monash University, Clayton, Melbourne, VIC 3800, Australia
| | - Mihails Delmans
- Department of Plant Sciences, University of Cambridge, Cambridge CB3 EA, UK
| | | | - Linda Silvestri
- Department of Plant Sciences, University of Cambridge, Cambridge CB3 EA, UK
| | - Jenna Rever
- Department of Plant Sciences, University of Cambridge, Cambridge CB3 EA, UK
| | - John L Bowman
- School of Biological Sciences, Monash University, Clayton, Melbourne, VIC 3800, Australia
- ARC Centre of Excellence for Plant Success in Nature and Agriculture, Monash University, Clayton, Melbourne, VIC 3800, Australia
| | - Ignacio Romani
- Departamento de Ciencias Sociales, Universidad Nacional de Quilmes, Bernal, Buenos Aires 1876, Argentina
| | - Jim Haseloff
- Department of Plant Sciences, University of Cambridge, Cambridge CB3 EA, UK
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2
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Arnoux-Courseaux M, Coudert Y. Re-examining meristems through the lens of evo-devo. TRENDS IN PLANT SCIENCE 2024; 29:413-427. [PMID: 38040554 DOI: 10.1016/j.tplants.2023.11.003] [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: 07/26/2023] [Revised: 10/25/2023] [Accepted: 11/03/2023] [Indexed: 12/03/2023]
Abstract
The concept of the meristem was introduced in 1858 to characterize multicellular, formative, and proliferative tissues that give rise to the entire plant body, based on observations of vascular plants. Although its original definition did not encompass bryophytes, this concept has been used and continuously refined over the past 165 years to describe the diverse apices of all land plants. Here, we re-examine this matter in light of recent evo-devo research and show that, despite displaying high anatomical diversity, land plant meristems are unified by shared genetic control. We also propose a modular view of meristem function and highlight multiple evolutionary mechanisms that are likely to have contributed to the assembly and diversification of the varied meristems during the course of plant evolution.
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Affiliation(s)
- Moïra Arnoux-Courseaux
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, INRIA, Lyon 69007, France; Laboratoire Physiologie Cellulaire et Végétale, Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG-DBSCI-LPCV, 17 avenue des Martyrs, F-38054, Grenoble, France
| | - Yoan Coudert
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, INRIA, Lyon 69007, France.
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3
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Liu Y, Yang Y, Wang R, Liu M, Ji X, He Y, Zhao B, Li W, Mo X, Zhang X, Gu Z, Pan B, Liu Y, Tadege M, Chen J, He L. Control of compound leaf patterning by MULTI-PINNATE LEAF1 (MPL1) in chickpea. Nat Commun 2023; 14:8088. [PMID: 38062032 PMCID: PMC10703836 DOI: 10.1038/s41467-023-43975-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 11/26/2023] [Indexed: 12/18/2023] Open
Abstract
Plant lateral organs are often elaborated through repetitive formation of developmental units, which progress robustly in predetermined patterns along their axes. Leaflets in compound leaves provide an example of such units that are generated sequentially along the longitudinal axis, in species-specific patterns. In this context, we explored the molecular mechanisms underlying an acropetal mode of leaflet initiation in chickpea pinnate compound leaf patterning. By analyzing naturally occurring mutants multi-pinnate leaf1 (mpl1) that develop higher-ordered pinnate leaves with more than forty leaflets, we show that MPL1 encoding a C2H2-zinc finger protein sculpts a morphogenetic gradient along the proximodistal axis of the early leaf primordium, thereby conferring the acropetal leaflet formation. This is achieved by defining the spatiotemporal expression pattern of CaLEAFY, a key regulator of leaflet initiation, and also perhaps by modulating the auxin signaling pathway. Our work provides novel molecular insights into the sequential progression of leaflet formation.
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Affiliation(s)
- Ye Liu
- Division of Life Sciences and Medicine, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
| | - Yuanfan Yang
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- School of Ecology and Environmental Sciences, Yunnan University, Kunming, Yunnan, 650500, China
| | - Ruoruo Wang
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Mingli Liu
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- College of Life Science, Southwest Forestry University, Kunming, China
| | - Xiaomin Ji
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yexin He
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
| | - Baolin Zhao
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
| | - Wenju Li
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- College of Life Science, Southwest Forestry University, Kunming, China
| | - Xiaoyu Mo
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiaojia Zhang
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
| | - Zhijia Gu
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, 650201, China
| | - Bo Pan
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Yu Liu
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China
| | - Million Tadege
- Department of Plant and Soil Sciences, Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK, 73401, USA.
| | - Jianghua Chen
- Division of Life Sciences and Medicine, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China.
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China.
- University of Chinese Academy of Sciences, Beijing, China.
- College of Life Science, Southwest Forestry University, Kunming, China.
| | - Liangliang He
- CAS Key Laboratory of Topical Plant Resources and Sustainable Use, State Key Laboratory of Plant Diversity and Specialty Crops, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan, 650223, China.
- University of Chinese Academy of Sciences, Beijing, China.
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Genome-Wide Identification of Wheat KNOX Gene Family and Functional Characterization of TaKNOX14-D in Plants. Int J Mol Sci 2022; 23:ijms232415918. [PMID: 36555558 PMCID: PMC9784718 DOI: 10.3390/ijms232415918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 12/05/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022] Open
Abstract
The KNOX genes play important roles in maintaining SAM and regulating the development of plant leaves. However, the TaKNOX genes in wheat are still not well understood, especially their role in abiotic stress. In this study, a total of 36 KNOX genes were identified, and we demonstrated the function of the TaKNOX14-D gene under mechanical injury and cold stress. Thirty-six TaKNOX genes were divided into two groups, and thirty-four TaKNOX genes were predicted to be located in the nucleus by Cell-PLoc. These genes contained five tandem duplications. Fifteen collinear gene pairs were exhibited in wheat and rice, one collinear gene pair was exhibited in wheat and Arabidopsis. The phylogenetic tree and motif analysis suggested that the TaKNOX gene appeared before C3 and C4 diverged. Gene structure showed that the numbers of exons and introns in TaKNOX gene are different. Wheat TaKNOX genes showed different expression patterns during the wheat growth phase, with seven TaKNOX genes being highly expressed in the whole growth period. These seven genes were also highly expressed in most tissues, and also responded to most abiotic stress. Eleven TaKNOX genes were up-regulated in the tillering node during the leaf regeneration period after mechanical damage. When treating the wheat with different hormones, the expression patterns of TaKNOX were changed, and results showed that ABA promoted TaKNOX expression and seven TaKNOX genes were up-regulated under cytokinin and auxin treatment. Overexpression of the TaKNOX14-D gene in Arabidopsis could increase the leaf size, plant height and seed size. This gene overexpression in Arabidopsis also increased the compensatory growth capacity after mechanical damage. Overexpression lines also showed high resistance to cold stress. This study provides a better understanding of the TaKNOX genes.
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5
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Li G, Yang J, Chen Y, Zhao X, Chen Y, Kimura S, Hu S, Hou H. SHOOT MERISTEMLESS participates in the heterophylly of Hygrophila difformis (Acanthaceae). PLANT PHYSIOLOGY 2022; 190:1777-1791. [PMID: 35984299 PMCID: PMC9614456 DOI: 10.1093/plphys/kiac382] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 07/23/2022] [Indexed: 06/15/2023]
Abstract
In heterophyllous plants, leaf shape shows remarkable plasticity in response to environmental conditions. However, transgenic studies of heterophylly are lacking and the molecular mechanism remains unclear. Here, we cloned the KNOTTED1-LIKE HOMEOBOX family gene SHOOT MERISTEMLESS (STM) from the heterophyllous plant Hygrophila difformis (Acanthaceae). We used molecular, morphogenetic, and biochemical tools to explore its functions in heterophylly. HdSTM was detected in different organs of H. difformis, and its expression changed with environmental conditions. Heterologous, ectopic expression of HdSTM in Arabidopsis (Arabidopsis thaliana) increased leaf complexity and CUP-SHAPED COTYLEDON (CUC) transcript levels. However, overexpression of HdSTM in H. difformis did not induce the drastic leaf change in the terrestrial condition. Overexpression of HdSTM in H. difformis induced quick leaf variations in submergence, while knockdown of HdSTM led to disturbed leaf development and weakened heterophylly in H. difformis. HdCUC3 had the same spatiotemporal expression pattern as HdSTM. Biochemical analysis revealed a physical interaction between HdSTM and HdCUC3. Our results provide genetic evidence that HdSTM is involved in regulating heterophylly in H. difformis.
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Affiliation(s)
- Gaojie Li
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Jingjing Yang
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yimeng Chen
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuyao Zhao
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yan Chen
- The State Key Laboratory of Freshwater Ecology and Biotechnology, The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Seisuke Kimura
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
- Center for Plant Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Shiqi Hu
- Zhejiang Marine Development Research Institute, Zhoushan 316021, China
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6
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Fouracre JP, Harrison CJ. How was apical growth regulated in the ancestral land plant? Insights from the development of non-seed plants. PLANT PHYSIOLOGY 2022; 190:100-112. [PMID: 35771646 PMCID: PMC9434304 DOI: 10.1093/plphys/kiac313] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
Land plant life cycles are separated into distinct haploid gametophyte and diploid sporophyte stages. Indeterminate apical growth evolved independently in bryophyte (moss, liverwort, and hornwort) and fern gametophytes, and tracheophyte (vascular plant) sporophytes. The extent to which apical growth in tracheophytes co-opted conserved gametophytic gene networks, or exploited ancestral sporophytic networks, is a long-standing question in plant evolution. The recent phylogenetic confirmation of bryophytes and tracheophytes as sister groups has led to a reassessment of the nature of the ancestral land plant. Here, we review developmental genetic studies of apical regulators and speculate on their likely evolutionary history.
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Affiliation(s)
| | - C Jill Harrison
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK
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7
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Abstract
There can be no doubt that early land plant evolution transformed the planet but, until recently, how and when this was achieved was unclear. Coincidence in the first appearance of land plant fossils and formative shifts in atmospheric oxygen and CO2 are an artefact of the paucity of earlier terrestrial rocks. Disentangling the timing of land plant bodyplan assembly and its impact on global biogeochemical cycles has been precluded by uncertainty concerning the relationships of bryophytes to one another and to the tracheophytes, as well as the timescale over which these events unfolded. New genome and transcriptome sequencing projects, combined with the application of sophisticated phylogenomic modelling methods, have yielded increasing support for the Setaphyta clade of liverworts and mosses, within monophyletic bryophytes. We consider the evolution of anatomy, genes, genomes and of development within this phylogenetic context, concluding that many vascular plant (tracheophytes) novelties were already present in a comparatively complex last common ancestor of living land plants (embryophytes). Molecular clock analyses indicate that embryophytes emerged in a mid-Cambrian to early Ordovician interval, compatible with hypotheses on their role as geoengineers, precipitating early Palaeozoic glaciations.
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Affiliation(s)
- Philip C J Donoghue
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK.
| | - C Jill Harrison
- School of Biological Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Jordi Paps
- School of Biological Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Harald Schneider
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK; Center of Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, China
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8
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Dierschke T, Flores-Sandoval E, Rast-Somssich MI, Althoff F, Zachgo S, Bowman JL. Gamete expression of TALE class HD genes activates the diploid sporophyte program in Marchantia polymorpha. eLife 2021; 10:57088. [PMID: 34533136 PMCID: PMC8476127 DOI: 10.7554/elife.57088] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 09/15/2021] [Indexed: 12/16/2022] Open
Abstract
Eukaryotic life cycles alternate between haploid and diploid phases and in phylogenetically diverse unicellular eukaryotes, expression of paralogous homeodomain genes in gametes primes the haploid-to-diploid transition. In the unicellular chlorophyte alga Chlamydomonas, KNOX and BELL TALE-homeodomain genes mediate this transition. We demonstrate that in the liverwort Marchantia polymorpha, paternal (sperm) expression of three of five phylogenetically diverse BELL genes, MpBELL234, and maternal (egg) expression of both MpKNOX1 and MpBELL34 mediate the haploid-to-diploid transition. Loss-of-function alleles of MpKNOX1 result in zygotic arrest, whereas a loss of either maternal or paternal MpBELL234 results in variable zygotic and early embryonic arrest. Expression of MpKNOX1 and MpBELL34 during diploid sporophyte development is consistent with a later role for these genes in patterning the sporophyte. These results indicate that the ancestral mechanism to activate diploid gene expression was retained in early diverging land plants and subsequently co-opted during evolution of the diploid sporophyte body.
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Affiliation(s)
- Tom Dierschke
- School of Biological Sciences, Monash University, Melbourne, Australia.,Botany Department, University of Osnabrück, Osnabrück, Germany
| | | | | | - Felix Althoff
- Botany Department, University of Osnabrück, Osnabrück, Germany
| | - Sabine Zachgo
- Botany Department, University of Osnabrück, Osnabrück, Germany
| | - John L Bowman
- School of Biological Sciences, Monash University, Melbourne, Australia
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9
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Romanova MA, Maksimova AI, Pawlowski K, Voitsekhovskaja OV. YABBY Genes in the Development and Evolution of Land Plants. Int J Mol Sci 2021; 22:4139. [PMID: 33923657 PMCID: PMC8074164 DOI: 10.3390/ijms22084139] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 12/27/2022] Open
Abstract
Mounting evidence from genomic and transcriptomic studies suggests that most genetic networks regulating the morphogenesis of land plant sporophytes were co-opted and modified from those already present in streptophyte algae and gametophytes of bryophytes sensu lato. However, thus far, no candidate genes have been identified that could be responsible for "planation", a conversion from a three-dimensional to a two-dimensional growth pattern. According to the telome theory, "planation" was required for the genesis of the leaf blade in the course of leaf evolution. The key transcription factors responsible for leaf blade development in angiosperms are YABBY proteins, which until recently were thought to be unique for seed plants. Yet, identification of a YABBY homologue in a green alga and the recent findings of YABBY homologues in lycophytes and hornworts suggest that YABBY proteins were already present in the last common ancestor of land plants. Thus, these transcriptional factors could have been involved in "planation", which fosters our understanding of the origin of leaves. Here, we summarise the current data on functions of YABBY proteins in the vegetative and reproductive development of diverse angiosperms and gymnosperms as well as in the development of lycophytes. Furthermore, we discuss a putative role of YABBY proteins in the genesis of multicellular shoot apical meristems and in the evolution of leaves in early divergent terrestrial plants.
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Affiliation(s)
- Marina A. Romanova
- Department of Botany, St. Petersburg State University, Universitetskaya Nab. 7/9, 190034 Saint Petersburg, Russia
| | - Anastasiia I. Maksimova
- Laboratory of Molecular and Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, ul. Professora Popova 2, 197376 Saint Petersburg, Russia;
| | - Katharina Pawlowski
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden;
| | - Olga V. Voitsekhovskaja
- Laboratory of Molecular and Ecological Physiology, Komarov Botanical Institute, Russian Academy of Sciences, ul. Professora Popova 2, 197376 Saint Petersburg, Russia;
- Saint Petersburg Electrotechnical University “LETI”, ul. Professora Popova 5, 197022 Saint Petersburg, Russia
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10
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Meade LE, Plackett ARG, Hilton J. Reconstructing development of the earliest seed integuments raises a new hypothesis for the evolution of ancestral seed-bearing structures. THE NEW PHYTOLOGIST 2021; 229:1782-1794. [PMID: 32639670 DOI: 10.1111/nph.16792] [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: 05/01/2020] [Accepted: 06/28/2020] [Indexed: 06/11/2023]
Abstract
How plant seeds originated remains unresolved, in part due to disconnects between fossil intermediates and developmental genetics in extant species. The Carboniferous fossil Genomosperma is considered among the most primitive known seeds, with highly lobed integument and exposed nucellus. We have used this key fossil taxon to investigate the evolutionary origins of seed development. We examined sectioned Genomosperma specimens using modern digital 3D reconstruction techniques and established population-level measurements of Genomosperma ovules for quantitative analysis. Genomosperma ovules show significant variation in integumentary lobe fusion and curvature. Our analysis suggests that this variation represents a single species with significant variations in lobe number and fusion, reminiscent of floral development in extant species. We conclude that changes in lobe flexure occurred late in development, consistent with a previously hypothesized function in pollen guidance/retention. We also identify seeds of Genomosperma within cupules for the first time. The presence of a cupule adds evidence towards the plesiomorphy of cupules within seed plants. Together with the similarities identified between the Genomosperma lobed integument and floral organs, we propose that the cupule, integument and nucellus together developed in a shoot-like fashion, potentially ancestral to extant seed plant reproductive shoots.
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Affiliation(s)
- Luke E Meade
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Andrew R G Plackett
- Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Jason Hilton
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
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11
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Aragón-Raygoza A, Vasco A, Blilou I, Herrera-Estrella L, Cruz-Ramírez A. Development and Cell Cycle Activity of the Root Apical Meristem in the Fern Ceratopteris richardii. Genes (Basel) 2020; 11:E1455. [PMID: 33291610 PMCID: PMC7761924 DOI: 10.3390/genes11121455] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/23/2020] [Accepted: 11/26/2020] [Indexed: 12/11/2022] Open
Abstract
Ferns are a representative clade in plant evolution although underestimated in the genomic era. Ceratopteris richardii is an emergent model for developmental processes in ferns, yet a complete scheme of the different growth stages is necessary. Here, we present a developmental analysis, at the tissue and cellular levels, of the first shoot-borne root of Ceratopteris. We followed early stages and emergence of the root meristem in sporelings. While assessing root growth, the first shoot-borne root ceases its elongation between the emergence of the fifth and sixth roots, suggesting Ceratopteris roots follow a determinate developmental program. We report cell division frequencies in the stem cell niche after detecting labeled nuclei in the root apical cell (RAC) and derivatives after 8 h of exposure. These results demonstrate the RAC has a continuous mitotic activity during root development. Detection of cell cycle activity in the RAC at early times suggests this cell acts as a non-quiescent organizing center. Overall, our results provide a framework to study root function and development in ferns and to better understand the evolutionary history of this organ.
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Affiliation(s)
- Alejandro Aragón-Raygoza
- Molecular and Developmental Complexity Group at Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad, Cinvestav Sede Irapuato, Km. 9.6 Libramiento Norte Carretera, Irapuato-León, Irapuato 36821, Guanajuato, Mexico;
- Metabolic Engineering Group, Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad, Cinvestav Sede Irapuato, Km. 9.6 Libramiento Norte Carretera, Irapuato-León, Irapuato 36821, Guanajuato, Mexico;
| | - Alejandra Vasco
- Botanical Research Institute of Texas (BRIT), Fort Worth, TX 76107-3400, USA;
| | - Ikram Blilou
- Laboratory of Plant Cell and Developmental Biology, Division of Biological and Environmental Sciences and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia;
| | - Luis Herrera-Estrella
- Metabolic Engineering Group, Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad, Cinvestav Sede Irapuato, Km. 9.6 Libramiento Norte Carretera, Irapuato-León, Irapuato 36821, Guanajuato, Mexico;
- Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA
| | - Alfredo Cruz-Ramírez
- Molecular and Developmental Complexity Group at Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad, Cinvestav Sede Irapuato, Km. 9.6 Libramiento Norte Carretera, Irapuato-León, Irapuato 36821, Guanajuato, Mexico;
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12
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Spencer V, Nemec Venza Z, Harrison CJ. What can lycophytes teach us about plant evolution and development? Modern perspectives on an ancient lineage. Evol Dev 2020; 23:174-196. [PMID: 32906211 DOI: 10.1111/ede.12350] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 08/04/2020] [Accepted: 08/04/2020] [Indexed: 02/06/2023]
Abstract
All Evo-Devo studies rely on representative sampling across the tree of interest to elucidate evolutionary trajectories through time. In land plants, genetic resources are well established in model species representing lineages including bryophytes (mosses, liverworts, and hornworts), monilophytes (ferns and allies), and seed plants (gymnosperms and flowering plants), but few resources are available for lycophytes (club mosses, spike mosses, and quillworts). Living lycophytes are a sister group to the euphyllophytes (the fern and seed plant clade), and have retained several ancestral morphological traits despite divergence from a common ancestor of vascular plants around 420 million years ago. This sister relationship offers a unique opportunity to study the conservation of traits such as sporophyte branching, vasculature, and indeterminacy, as well as the convergent evolution of traits such as leaves and roots which have evolved independently in each vascular plant lineage. To elucidate the evolution of vascular development and leaf formation, molecular studies using RNA Seq, quantitative reverse transcription polymerase chain reaction, in situ hybridisation and phylogenetics have revealed the diversification and expression patterns of KNOX, ARP, HD-ZIP, KANADI, and WOX gene families in lycophytes. However, the molecular basis of further trait evolution is not known. Here we describe morphological traits of living lycophytes and their extinct relatives, consider the molecular underpinnings of trait evolution and discuss future research required in lycophytes to understand the key evolutionary innovations enabling the growth and development of all vascular plants.
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Affiliation(s)
- Victoria Spencer
- School of Biological Sciences, The University of Bristol, Bristol, UK
| | - Zoe Nemec Venza
- School of Biological Sciences, The University of Bristol, Bristol, UK
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13
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Vasco A, Ambrose BA. Simple and Divided Leaves in Ferns: Exploring the Genetic Basis for Leaf Morphology Differences in the Genus Elaphoglossum (Dryopteridaceae). Int J Mol Sci 2020; 21:E5180. [PMID: 32707812 PMCID: PMC7432805 DOI: 10.3390/ijms21155180] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/01/2020] [Accepted: 07/18/2020] [Indexed: 12/29/2022] Open
Abstract
Despite the implications leaves have for life, their origin and development remain debated. Analyses across ferns and seed plants are fundamental to address the conservation or independent origins of megaphyllous leaf developmental mechanisms. Class I KNOX expression studies have been used to understand leaf development and, in ferns, have only been conducted in species with divided leaves. We performed expression analyses of the Class I KNOX and Histone H4 genes throughout the development of leaf primordia in two simple-leaved and one divided-leaved fern taxa. We found Class I KNOX are expressed (1) throughout young and early developing leaves of simple and divided-leaved ferns, (2) later into leaf development of divided-leaved species compared to simple-leaved species, and (3) at the leaf primordium apex and margins. H4 expression is similar in young leaf primordia of simple and divided leaves. Persistent Class I KNOX expression at the margins of divided leaf primordia compared with simple leaf primordia indicates that temporal and spatial patterns of Class I KNOX expression correlate with different fern leaf morphologies. However, our results also indicate that Class I KNOX expression alone is not sufficient to promote divided leaf development in ferns. Class I KNOX patterns of expression in fern leaves support the conservation of an independently recruited developmental mechanism for leaf dissection in megaphylls, the shoot-like nature of fern leaves compared with seed plant leaves, and the critical role marginal meristems play in fern leaf development.
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Affiliation(s)
- Alejandra Vasco
- Botanical Research Institute of Texas, 1700 University Drive, Fort Worth, TX 76107-3400, USA
| | - Barbara A. Ambrose
- The New York Botanical Garden, 2900 Southern Blvd, Bronx, NY 10458-5126, USA
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14
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Cruz R, Melo-de-Pinna GFA, Vasco A, Prado J, Ambrose BA. Class I KNOX Is Related to Determinacy during the Leaf Development of the Fern Mickelia scandens (Dryopteridaceae). Int J Mol Sci 2020; 21:ijms21124295. [PMID: 32560264 PMCID: PMC7352642 DOI: 10.3390/ijms21124295] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 06/08/2020] [Accepted: 06/12/2020] [Indexed: 12/19/2022] Open
Abstract
Unlike seed plants, ferns leaves are considered to be structures with delayed determinacy, with a leaf apical meristem similar to the shoot apical meristems. To better understand the meristematic organization during leaf development and determinacy control, we analyzed the cell divisions and expression of Class I KNOX genes in Mickelia scandens, a fern that produces larger leaves with more pinnae in its climbing form than in its terrestrial form. We performed anatomical, in situ hybridization, and qRT-PCR experiments with histone H4 (cell division marker) and Class I KNOX genes. We found that Class I KNOX genes are expressed in shoot apical meristems, leaf apical meristems, and pinnae primordia. During early development, cell divisions occur in the most distal regions of the analyzed structures, including pinnae, and are not restricted to apical cells. Fern leaves and pinnae bear apical meristems that may partially act as indeterminate shoots, supporting the hypothesis of homology between shoots and leaves. Class I KNOX expression is correlated with indeterminacy in the apex and leaf of ferns, suggesting a conserved function for these genes in euphyllophytes with compound leaves.
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Affiliation(s)
- Rafael Cruz
- Instituto de Botânica, Av. Miguel Estéfano 3687, São Paulo (SP) CEP 04301-902, Brazil;
- Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, São Paulo (SP) CEP 05422-971, Brazil;
- Correspondence:
| | - Gladys F. A. Melo-de-Pinna
- Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, São Paulo (SP) CEP 05422-971, Brazil;
| | - Alejandra Vasco
- Botanical Research Institute of Texas, 1700 University Drive, Fort Worth, TX 76107-3400, USA;
| | - Jefferson Prado
- Instituto de Botânica, Av. Miguel Estéfano 3687, São Paulo (SP) CEP 04301-902, Brazil;
- UNESP, IBILCE, Depto. de Zoologia e Botânica, Rua Cristóvão Colombo, 2265, São José do Rio Preto (SP) CEP 15054-000, Brazil
| | - Barbara A. Ambrose
- The New York Botanical Garden, 2900 Southern Blvd, Bronx, NY 10458-5126, USA;
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15
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Kirbis A, Waller M, Ricca M, Bont Z, Neubauer A, Goffinet B, Szövényi P. Transcriptional Landscapes of Divergent Sporophyte Development in Two Mosses, Physcomitrium (Physcomitrella) patens and Funaria hygrometrica. FRONTIERS IN PLANT SCIENCE 2020; 11:747. [PMID: 32587596 PMCID: PMC7299128 DOI: 10.3389/fpls.2020.00747] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 05/11/2020] [Indexed: 05/03/2023]
Abstract
Understanding the molecular basis of morphological shifts is a fundamental question of evolutionary biology. New morphologies may arise through the birth/death of genes (gene gain/loss) or by reutilizing existing gene sets. Yet, the relative contribution of these two processes to radical morphological shifts is still poorly understood. Here, we use the model system of two mosses, Funaria hygrometrica and Physcomitrium (Physcomitrella) patens, to investigate the molecular mechanisms underlying contrasting sporophyte architectures. We used comparative analysis of time-series expression data for four stages of sporophyte development in both species to address this question in detail. We found that large-scale differences in sporophytic architecture are mainly governed by orthologous (i.e., shared) genes frequently experiencing temporal gene expression shifts between the two species. While the absolute number of species-specific genes expressed during sporophyte development is somewhat smaller, we observed a significant increase of their proportion in preferentially sporophyte expressed genes, suggesting a fundamental role in the sporophyte phase. However, further functional studies are necessary to determine their contribution to diverging sporophyte morphologies. Our results add to the growing set of studies suggesting that radical changes in morphology may rely on the heterochronic expression of conserved regulators.
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Affiliation(s)
- Alexander Kirbis
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Manuel Waller
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Mariana Ricca
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Zoe Bont
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Anna Neubauer
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Bernard Goffinet
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, United States
| | - Péter Szövényi
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich and Zurich-Basel Plant Science Center, Zurich, Switzerland
- *Correspondence: Péter Szövényi,
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16
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The Evolution of the KANADI Gene Family and Leaf Development in Lycophytes and Ferns. PLANTS 2019; 8:plants8090313. [PMID: 31480252 PMCID: PMC6783990 DOI: 10.3390/plants8090313] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/16/2019] [Accepted: 08/20/2019] [Indexed: 12/23/2022]
Abstract
Leaves constitute the main photosynthetic plant organ and even though their importance is not debated, the origin and development of leaves still is. The leaf developmental network has been elucidated for angiosperms, from genes controlling leaf initiation, to leaf polarity and shape. There are four KANADI (KAN) paralogs in Arabidopsisthaliana needed for organ polarity with KAN1 and KAN2 specifying abaxial leaf identity. Yet, studies of this gene lineage outside angiosperms are required to better understand the evolutionary patterns of leaf development and the role of KAN homologs. We studied the evolution of KAN genes across vascular plants and their expression by in situ hybridization in the fern, Equisetum hyemale and the lycophyte Selaginella moellendorffii. Our results show that the expression of KAN genes in leaves is similar between ferns and angiosperms. However, the expression patterns observed in the lycophyte S. moellendorffii are significantly different compared to all other vascular plants, suggesting that the KAN function in leaf polarity is likely only conserved across ferns, gymnosperms, and angiosperms. This study indicates that mechanisms for leaf development are different in lycophytes compared to other vascular plants.
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Conway SJ, Di Stilio VS. An ontogenetic framework for functional studies in the model fern Ceratopteris richardii. Dev Biol 2019; 457:20-29. [PMID: 31470018 DOI: 10.1016/j.ydbio.2019.08.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 08/21/2019] [Accepted: 08/26/2019] [Indexed: 01/02/2023]
Abstract
As the sister group to seed plants, ferns are a phylogenetically informative lineage. Functional studies in representatives of the fern lineage are helping bridge the knowledge gap in developmental mechanisms between angiosperms and non-vascular plants. The fern life cycle has the advantage of combining a sizable free-living haploid gametophyte, more amenable for developmental studies than the reduced seed plant gametophyte, with an indeterminate and complex diploid sporophyte. Ceratopteris richardii has long been proposed as a model fern and has recently become tractable due to stable transgenesis and increasing genomic resources, allowing researchers to test explicit questions about gene function in a fern for the first time. As with any model system, a detailed understanding of wild-type morphology and a staged ontogeny are indispensable for the characterization of mutant phenotypes resulting from genetic manipulations. Therefore, the goal of this study is to provide a unified reference ontogeny for this emerging model fern as a tool for comparative evolutionary and developmental studies. It complements earlier research by filling gaps in major stages of development of the haploid gametophyte and diploid sporophyte generations, and provides additional descriptions of the shoot apical meristem and early leaf development. This resource is meant to facilitate not only studies of candidate genes within C. richardii, but also broader ontogenetic comparisons to other model plants.
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Affiliation(s)
- Stephanie J Conway
- Department of Biology, University of Washington, Seattle, WA, 98195-1800, USA.
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18
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Lipinska AP, Serrano-Serrano ML, Cormier A, Peters AF, Kogame K, Cock JM, Coelho SM. Rapid turnover of life-cycle-related genes in the brown algae. Genome Biol 2019; 20:35. [PMID: 30764885 PMCID: PMC6374913 DOI: 10.1186/s13059-019-1630-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 01/16/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sexual life cycles in eukaryotes involve a cyclic alternation between haploid and diploid phases. While most animals possess a diploid life cycle, many plants and algae alternate between multicellular haploid (gametophyte) and diploid (sporophyte) generations. In many algae, gametophytes and sporophytes are independent and free-living and may present dramatic phenotypic differences. The same shared genome can therefore be subject to different, even conflicting, selection pressures during each of the life cycle generations. Here, we analyze the nature and extent of genome-wide, generation-biased gene expression in four species of brown algae with contrasting levels of dimorphism between life cycle generations. RESULTS We show that the proportion of the transcriptome that is generation-specific is broadly associated with the level of phenotypic dimorphism between the life cycle stages. Importantly, our data reveals a remarkably high turnover rate for life-cycle-related gene sets across the brown algae and highlights the importance not only of co-option of regulatory programs from one generation to the other but also of a role for newly emerged, lineage-specific gene expression patterns in the evolution of the gametophyte and sporophyte developmental programs in this major eukaryotic group. Moreover, we show that generation-biased genes display distinct evolutionary modes, with gametophyte-biased genes evolving rapidly at the coding sequence level whereas sporophyte-biased genes tend to exhibit changes in their patterns of expression. CONCLUSION Our analysis uncovers the characteristics, expression patterns, and evolution of generation-biased genes and underlines the selective forces that shape this previously underappreciated source of phenotypic diversity.
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Affiliation(s)
- Agnieszka P Lipinska
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Algal Genetics Group, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
| | | | - Alexandre Cormier
- Laboratoire Ecologie et Biologie des Interactions, Equipe Ecologie Evolution Symbiose, Université de Poitiers, UMR CNRS 7267, Poitiers, France
| | | | - Kazuhiro Kogame
- Department of Biological Sciences, Faculty of Sciences, Hokkaido University, Sapporo, 060-0810, Japan
| | - J Mark Cock
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Algal Genetics Group, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
| | - Susana M Coelho
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Algal Genetics Group, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France.
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19
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20
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Abstract
Land plants evolved from an ancestral alga from which they inherited developmental and physiological characters. A key innovation of land plants is a life cycle with an alternation of generations, with both haploid gametophyte and diploid sporophyte generations having complex multicellular bodies. The origins of the developmental genetic programs patterning these bodies, whether inherited from an algal ancestor or evolved de novo, and whether programs were co-opted between generations, are largely open questions. We first provide a framework for land plant evolution and co-option of developmental regulatory pathways and then examine two cases in more detail.
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21
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Bartz M, Gola EM. Meristem development and activity in gametophytes of the model fern, Ceratopteris richardii. Dev Biol 2018; 444:107-115. [DOI: 10.1016/j.ydbio.2018.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 09/21/2018] [Accepted: 10/11/2018] [Indexed: 12/14/2022]
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22
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Plackett AR, Conway SJ, Hewett Hazelton KD, Rabbinowitsch EH, Langdale JA, Di Stilio VS. LEAFY maintains apical stem cell activity during shoot development in the fern Ceratopteris richardii. eLife 2018; 7:39625. [PMID: 30355440 PMCID: PMC6200394 DOI: 10.7554/elife.39625] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 09/22/2018] [Indexed: 12/29/2022] Open
Abstract
During land plant evolution, determinate spore-bearing axes (retained in extant bryophytes such as mosses) were progressively transformed into indeterminate branching shoots with specialized reproductive axes that form flowers. The LEAFY transcription factor, which is required for the first zygotic cell division in mosses and primarily for floral meristem identity in flowering plants, may have facilitated developmental innovations during these transitions. Mapping the LEAFY evolutionary trajectory has been challenging, however, because there is no functional overlap between mosses and flowering plants, and no functional data from intervening lineages. Here, we report a transgenic analysis in the fern Ceratopteris richardii that reveals a role for LEAFY in maintaining cell divisions in the apical stem cells of both haploid and diploid phases of the lifecycle. These results support an evolutionary trajectory in which an ancestral LEAFY module that promotes cell proliferation was progressively co-opted, adapted and specialized as novel shoot developmental contexts emerged. The first plants colonized land around 500 million years ago. These plants had simple shoots with no branches, similar to the mosses that live today. Later on, some plants evolved more complex structures including branched shoots and flowers (collectively known as the “flowering plants”). Ferns are a group of plants that evolved midway between the mosses and flowering plants and have branched shoots but no flowers. The gradual transition from simple to more complex plant structures required changes to the way in which cells divide and grow within plant shoots. Whereas animals produce new cells throughout their body, most plant cells divide in areas known as meristems. All plants grow from embryos, which contain meristems that will form the roots and shoots of the mature plant. A gene called LEAFY is required for cells in moss embryos to divide. However, in flowering plants LEAFY does not carry out this role, instead it is only required to make the meristems that produce flowers. How did LEAFY transition from a general role in embryos to a more specialized role in making flowers? To address this question, Plackett, Conway et al. studied the two LEAFY genes in a fern called Ceratopteris richardii. The experiments showed that at least one of these LEAFY genes was active in the meristems of fern shoots throughout the lifespan of the plant. The shoots of ferns with less active LEAFY genes could not form the leaves seen in normal C. richardii plants. This suggests that as land plants evolved, the role of LEAFY changed from forming embryos to forming complex shoot structures. Most of our major crops are flowering plants. By understanding how the role of LEAFY has changed over the evolution of land plants, it might be possible to manipulate LEAFY genes in crop plants to alter shoot structures to better suit specific environments.
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Affiliation(s)
- Andrew Rg Plackett
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
| | | | | | | | - Jane A Langdale
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
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23
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Harrison CJ, Morris JL. The origin and early evolution of vascular plant shoots and leaves. Philos Trans R Soc Lond B Biol Sci 2018; 373:20160496. [PMID: 29254961 PMCID: PMC5745332 DOI: 10.1098/rstb.2016.0496] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2017] [Indexed: 12/22/2022] Open
Abstract
The morphology of plant fossils from the Rhynie chert has generated longstanding questions about vascular plant shoot and leaf evolution, for instance, which morphologies were ancestral within land plants, when did vascular plants first arise and did leaves have multiple evolutionary origins? Recent advances combining insights from molecular phylogeny, palaeobotany and evo-devo research address these questions and suggest the sequence of morphological innovation during vascular plant shoot and leaf evolution. The evidence pinpoints testable developmental and genetic hypotheses relating to the origin of branching and indeterminate shoot architectures prior to the evolution of leaves, and demonstrates underestimation of polyphyly in the evolution of leaves from branching forms in 'telome theory' hypotheses of leaf evolution. This review discusses fossil, developmental and genetic evidence relating to the evolution of vascular plant shoots and leaves in a phylogenetic framework.This article is part of a discussion meeting issue 'The Rhynie cherts: our earliest terrestrial ecosystem revisited'.
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Affiliation(s)
- C Jill Harrison
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Jennifer L Morris
- School of Earth Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
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24
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Ruiz-Estévez M, Bakkali M, Martín-Blázquez R, Garrido-Ramos MA. Identification and Characterization of TALE Homeobox Genes in the Endangered Fern Vandenboschia speciosa. Genes (Basel) 2017; 8:E275. [PMID: 29039766 PMCID: PMC5664125 DOI: 10.3390/genes8100275] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 10/09/2017] [Accepted: 10/09/2017] [Indexed: 12/18/2022] Open
Abstract
We report and discuss the results of a quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis of the expression patterns of seven three amino acid loop extension (TALE) homeobox genes (four KNOTTED-like homeobox (KNOX) and three BEL1-like homeobox (BELL) genes) identified after next generation sequencing (NGS) and assembly of the sporophyte and gametophyte transcriptomes of the endangered fern species Vandenboschia speciosa. Among the four KNOX genes, two belonged to the KNOX1 class and the other two belonged to the KNOX2 class. Analysis of the deduced amino acid sequences supported the typical domain structure of both types of TALE proteins, and the homology to TALE proteins of mosses, lycophytes, and seed plant species. The expression analyses demonstrate that these homeodomain proteins appear to have a key role in the establishment and development of the gametophyte and sporophyte phases of V. speciosa lifecycle, as well as in the control of the transition between both phases. Vandenboschia speciosa VsKNAT3 (a KNOX2 class protein) as well as VsBELL4 and VsBELL10 proteins have higher expression levels during the sporophyte program. On the contrary, one V. speciosa KNOX1 protein (VsKNAT6) and one KNOX2 protein (VsKNAT4) seem important during the development of the gametophyte phase. TALE homeobox genes might be among the key regulators in the gametophyte-to-sporophyte developmental transition in regular populations that show alternation of generations, since some of the genes analyzed here (VsKNAT3, VsKNAT6, VsBELL4, and VsBELL6) are upregulated in a non-alternating population in which only independent gametophytes are found (they grow by vegetative reproduction outside of the range of sporophyte distribution). Thus, these four genes might trigger the vegetative propagation of the gametophyte and the repression of the sexual development in populations composed of independent gametophytes. This study represents a comprehensive identification and characterization of TALE homeobox genes in V. speciosa, and gives novel insights about the role of these genes in fern development.
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Affiliation(s)
- Mercedes Ruiz-Estévez
- Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
| | - Mohammed Bakkali
- Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
| | - Rubén Martín-Blázquez
- Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
| | - Manuel A Garrido-Ramos
- Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
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25
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Frangedakis E, Saint‐Marcoux D, Moody LA, Rabbinowitsch E, Langdale JA. Nonreciprocal complementation of KNOX gene function in land plants. THE NEW PHYTOLOGIST 2017; 216:591-604. [PMID: 27886385 PMCID: PMC5637896 DOI: 10.1111/nph.14318] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 09/30/2016] [Indexed: 05/02/2023]
Abstract
Class I KNOTTED-LIKE HOMEOBOX (KNOX) proteins regulate development of the multicellular diploid sporophyte in both mosses and flowering plants; however, the morphological context in which they function differs. In order to determine how Class I KNOX function was modified as land plants evolved, phylogenetic analyses and cross-species complementation assays were performed. Our data reveal that a duplication within the charophyte sister group to land plants led to distinct Class I and Class II KNOX gene families. Subsequently, Class I sequences diverged substantially in the nonvascular bryophyte groups (liverworts, mosses and hornworts), with moss sequences being most similar to those in vascular plants. Despite this similarity, moss mutants were not complemented by vascular plant KNOX genes. Conversely, the Arabidopsis brevipedicellus (bp-9) mutant was complemented by the PpMKN2 gene from the moss Physcomitrella patens. Lycophyte KNOX genes also complemented bp-9 whereas fern genes only partially complemented the mutant. This lycophyte/fern distinction is mirrored in the phylogeny of KNOX-interacting BELL proteins, in that a gene duplication occurred after divergence of the two groups. Together, our results imply that the moss MKN2 protein can function in a broader developmental context than vascular plant KNOX proteins, the narrower scope having evolved progressively as lycophytes, ferns and flowering plants diverged.
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Affiliation(s)
| | - Denis Saint‐Marcoux
- Department of Plant SciencesUniversity of OxfordSouth Parks RoadOxfordOX1 3RBUK
| | - Laura A. Moody
- Department of Plant SciencesUniversity of OxfordSouth Parks RoadOxfordOX1 3RBUK
| | - Ester Rabbinowitsch
- Department of Plant SciencesUniversity of OxfordSouth Parks RoadOxfordOX1 3RBUK
| | - Jane A. Langdale
- Department of Plant SciencesUniversity of OxfordSouth Parks RoadOxfordOX1 3RBUK
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Macaisne N, Liu F, Scornet D, Peters AF, Lipinska A, Perrineau MM, Henry A, Strittmatter M, Coelho SM, Cock JM. The Ectocarpus IMMEDIATE UPRIGHT gene encodes a member of a novel family of cysteine-rich proteins with an unusual distribution across the eukaryotes. Development 2017; 144:409-418. [PMID: 28049657 DOI: 10.1242/dev.141523] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 12/12/2016] [Indexed: 01/09/2023]
Abstract
The sporophyte generation of the brown alga Ectocarpus sp. exhibits an unusual pattern of development compared with the majority of brown algae. The first cell division is symmetrical and the apical-basal axis is established late in development. In the immediate upright (imm) mutant, the initial cell undergoes an asymmetric division to immediately establish the apical-basal axis. We provide evidence which suggests that this phenotype corresponds to the ancestral state of the sporophyte. The IMM gene encodes a protein of unknown function that contains a repeated motif also found in the EsV-1-7 gene of the Ectocarpus virus EsV-1. Brown algae possess large families of EsV-1-7 domain genes but these genes are rare in other stramenopiles, suggesting that the expansion of this family might have been linked with the emergence of multicellular complexity. EsV-1-7 domain genes have a patchy distribution across eukaryotic supergroups and occur in several viral genomes, suggesting possible horizontal transfer during eukaryote evolution.
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Affiliation(s)
- Nicolas Macaisne
- CNRS, Sorbonne Université, UPMC University Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, Roscoff F-29688, France
| | - Fuli Liu
- CNRS, Sorbonne Université, UPMC University Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, Roscoff F-29688, France
| | - Delphine Scornet
- CNRS, Sorbonne Université, UPMC University Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, Roscoff F-29688, France
| | | | - Agnieszka Lipinska
- CNRS, Sorbonne Université, UPMC University Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, Roscoff F-29688, France
| | - Marie-Mathilde Perrineau
- CNRS, Sorbonne Université, UPMC University Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, Roscoff F-29688, France
| | - Antoine Henry
- CNRS, Sorbonne Université, UPMC University Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, Roscoff F-29688, France
| | - Martina Strittmatter
- CNRS, Sorbonne Université, UPMC University Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, Roscoff F-29688, France
| | - Susana M Coelho
- CNRS, Sorbonne Université, UPMC University Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, Roscoff F-29688, France
| | - J Mark Cock
- CNRS, Sorbonne Université, UPMC University Paris 06, Algal Genetics Group, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, Roscoff F-29688, France
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Vasco A, Smalls TL, Graham SW, Cooper ED, Wong GKS, Stevenson DW, Moran RC, Ambrose BA. Challenging the paradigms of leaf evolution: Class III HD-Zips in ferns and lycophytes. THE NEW PHYTOLOGIST 2016; 212:745-758. [PMID: 27385116 DOI: 10.1111/nph.14075] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 05/23/2016] [Indexed: 05/06/2023]
Abstract
Despite the extraordinary significance leaves have for life on Earth, their origin and development remain vigorously debated. More than a century of paleobotanical, morphological, and phylogenetic research has still not resolved fundamental questions about leaves. Developmental genetic data are sparse in ferns, and comparative studies of lycophytes and seed plants have reached opposing conclusions on the conservation of a leaf developmental program. We performed phylogenetic and expression analyses of a leaf developmental regulator (Class III HD-Zip genes; C3HDZs) spanning lycophytes and ferns. We show that a duplication and neofunctionalization of C3HDZs probably occurred in the ancestor of euphyllophytes, and that there is a common leaf developmental mechanism conserved between ferns and seed plants. We show C3HDZ expression in lycophyte and fern sporangia and show that C3HDZs have conserved expression patterns during initiation of lateral primordia (leaves or sporangia). This expression is maintained throughout sporangium development in lycophytes and ferns and indicates an ancestral role of C3HDZs in sporangium development. We hypothesize that there is a deep homology of all leaves and that a sporangium-specific developmental program was coopted independently for the development of lycophyte and euphyllophyte leaves. This provides molecular genetic support for a paradigm shift in theories of lycophyte leaf evolution.
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Affiliation(s)
- Alejandra Vasco
- The New York Botanical Garden, 2900 Southern Blvd, Bronx, NY, 10458-5126, USA
- Instituto de Biología, Universidad Nacional Autónoma de México (UNAM), Mexico DF, 04510, Mexico
| | - Tynisha L Smalls
- The New York Botanical Garden, 2900 Southern Blvd, Bronx, NY, 10458-5126, USA
| | - Sean W Graham
- Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada
- UBC Botanical Garden & Centre for Plant Research, University of British Columbia, 6804 Marine Drive SW, Vancouver, BC, V6T 1Z4, Canada
| | - Endymion D Cooper
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Gane Ka-Shu Wong
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
- Department of Medicine, University of Alberta, Edmonton, AB, T6G 2E1, Canada
- BGI-Shenzhen, Beishan Industrial Zone, Yantian District, Shenzhen, 518083, China
| | - Dennis W Stevenson
- The New York Botanical Garden, 2900 Southern Blvd, Bronx, NY, 10458-5126, USA
| | - Robbin C Moran
- The New York Botanical Garden, 2900 Southern Blvd, Bronx, NY, 10458-5126, USA
| | - Barbara A Ambrose
- The New York Botanical Garden, 2900 Southern Blvd, Bronx, NY, 10458-5126, USA.
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28
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Lehti-Shiu MD, Panchy N, Wang P, Uygun S, Shiu SH. Diversity, expansion, and evolutionary novelty of plant DNA-binding transcription factor families. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1860:3-20. [PMID: 27522016 DOI: 10.1016/j.bbagrm.2016.08.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 07/21/2016] [Accepted: 08/06/2016] [Indexed: 12/19/2022]
Abstract
Plant transcription factors (TFs) that interact with specific sequences via DNA-binding domains are crucial for regulating transcriptional initiation and are fundamental to plant development and environmental response. In addition, expansion of TF families has allowed functional divergence of duplicate copies, which has contributed to novel, and in some cases adaptive, traits in plants. Thus, TFs are central to the generation of the diverse plant species that we see today. Major plant agronomic traits, including those relevant to domestication, have also frequently arisen through changes in TF coding sequence or expression patterns. Here our goal is to provide an overview of plant TF evolution by first comparing the diversity of DNA-binding domains and the sizes of these domain families in plants and other eukaryotes. Because TFs are among the most highly expanded gene families in plants, the birth and death process of TFs as well as the mechanisms contributing to their retention are discussed. We also provide recent examples of how TFs have contributed to novel traits that are important in plant evolution and in agriculture.This article is part of a Special Issue entitled: Plant Gene Regulatory Mechanisms and Networks, edited by Dr. Erich Grotewold and Dr. Nathan Springer.
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Affiliation(s)
| | - Nicholas Panchy
- The Genetics Graduate Program, Michigan State University, East Lansing, MI 48824, USA
| | - Peipei Wang
- Department of Plant Biology, East Lansing, MI 48824, USA
| | - Sahra Uygun
- The Genetics Graduate Program, Michigan State University, East Lansing, MI 48824, USA
| | - Shin-Han Shiu
- Department of Plant Biology, East Lansing, MI 48824, USA; The Genetics Graduate Program, Michigan State University, East Lansing, MI 48824, USA.
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29
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Ambrose BA, Vasco A. Bringing the multicellular fern meristem into focus. THE NEW PHYTOLOGIST 2016; 210:790-3. [PMID: 26756664 DOI: 10.1111/nph.13825] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Affiliation(s)
- Barbara A Ambrose
- The New York Botanical Garden, 2900 Southern Blvd., Bronx, NY, 10458, USA
| | - Alejandra Vasco
- The New York Botanical Garden, 2900 Southern Blvd., Bronx, NY, 10458, USA
- Instituto de Biología, Universidad Nacional Autónoma de México (UNAM), Mexico DF, 04510, Mexico
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30
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Yip HK, Floyd SK, Sakakibara K, Bowman JL. Class III HD-Zip activity coordinates leaf development in Physcomitrella patens. Dev Biol 2016; 419:184-197. [PMID: 26808209 DOI: 10.1016/j.ydbio.2016.01.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/17/2016] [Accepted: 01/19/2016] [Indexed: 10/22/2022]
Abstract
Land plant bodies develop from meristems, groups of pluripotent stem cells, which may persist throughout the life of a plant or, alternatively, have a transitory existence. Early diverging land plants exhibit indeterminate (persistent) growth in their haploid gametophytic generation, whereas later diverging lineages exhibit indeterminate growth in their diploid sporophytic generation, raising the question of whether genetic machinery directing meristematic functions was co-opted between generations. Class III HD-Zip (C3HDZ) genes are required for the establishment and maintenance of shoot apical meristems in flowering plants. We demonstrate that in the moss Physcomitrella patens, C3HDZ genes are expressed in transitory meristems in both the gametophytic and sporophytic generations, but not in the persistent shoot meristem of the gametyphyte. Loss-of-function of P. patens C3HDZ was engineered using ectopic expression of miR166, an endogenous regulator of C3HDZ gene activity. Loss of C3HDZ gene function impaired the function of gametophytic transitory meristematic activity but did not compromise the functioning of the persistent shoot apical meristem during the gametophyte generation. These results argue against a wholesale co-option of meristematic gene regulatory networks from the gametophyte to the sporophyte during land plant evolution, instead suggesting that persistent meristems with a single apical cell in P. patens and persistent complex meristems in flowering plants are regulated by different genetic programs.
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Affiliation(s)
- Hoichong Karen Yip
- Section of Plant Biology, UC Davis, One Shields Avenue, Davis 95616, CA, USA
| | - Sandra K Floyd
- Section of Plant Biology, UC Davis, One Shields Avenue, Davis 95616, CA, USA; School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - Keiko Sakakibara
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - John L Bowman
- Section of Plant Biology, UC Davis, One Shields Avenue, Davis 95616, CA, USA; School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia.
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31
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Frank MH, Edwards MB, Schultz ER, McKain MR, Fei Z, Sørensen I, Rose JKC, Scanlon MJ. Dissecting the molecular signatures of apical cell-type shoot meristems from two ancient land plant lineages. THE NEW PHYTOLOGIST 2015; 207:893-904. [PMID: 25900772 DOI: 10.1111/nph.13407] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 03/04/2015] [Indexed: 05/18/2023]
Abstract
Shoot apical meristem (SAM) structure varies markedly within the land plants. The SAMs of many seedless vascular plants contain a conspicuous inverted, pyramidal cell called the apical cell (AC), which is unidentified in angiosperms. In this study, we use transcriptomic sequencing with precise laser microdissections of meristem subdomains to define the molecular signatures of anatomically distinct zones from the AC-type SAMs of a lycophyte (Selaginella moellendorffii) and a monilophyte (Equisetum arvense). The two model species for this study represent vascular plant lineages that diverged > 400 million yr ago. Our data comprise comprehensive molecular signatures for the distinct subdomains within AC-type SAMs, an anatomical anomaly whose functional significance has been debated in the botanical literature for over two centuries. Moreover, our data provide molecular support for distinct gene expression programs between the AC-type SAMs of Selaginella and Equisetum, as compared with the SAM transcriptome of the angiosperm maize. The results are discussed in light of the functional significance and evolutionary success of the AC-type SAM within the embryophytes.
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Affiliation(s)
- Margaret H Frank
- Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Molly B Edwards
- Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Eric R Schultz
- Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA
| | | | - Zhangjun Fei
- Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY, 14853, USA
- USDA Robert W. Holley Center for Agriculture and Health, Ithaca, NY, 14853, USA
| | - Iben Sørensen
- Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Jocelyn K C Rose
- Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Michael J Scanlon
- Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA
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32
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Lutova LA, Dodueva IE, Lebedeva MA, Tvorogova VE. Transcription factors in developmental genetics and the evolution of higher plants. RUSS J GENET+ 2015. [DOI: 10.1134/s1022795415030084] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Furumizu C, Alvarez JP, Sakakibara K, Bowman JL. Antagonistic roles for KNOX1 and KNOX2 genes in patterning the land plant body plan following an ancient gene duplication. PLoS Genet 2015; 11:e1004980. [PMID: 25671434 PMCID: PMC4335488 DOI: 10.1371/journal.pgen.1004980] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 01/04/2015] [Indexed: 12/23/2022] Open
Abstract
Neofunctionalization following gene duplication is thought to be one of the key drivers in generating evolutionary novelty. A gene duplication in a common ancestor of land plants produced two classes of KNOTTED-like TALE homeobox genes, class I (KNOX1) and class II (KNOX2). KNOX1 genes are linked to tissue proliferation and maintenance of meristematic potentials of flowering plant and moss sporophytes, and modulation of KNOX1 activity is implicated in contributing to leaf shape diversity of flowering plants. While KNOX2 function has been shown to repress the gametophytic (haploid) developmental program during moss sporophyte (diploid) development, little is known about KNOX2 function in flowering plants, hindering syntheses regarding the relationship between two classes of KNOX genes in the context of land plant evolution. Arabidopsis plants harboring loss-of-function KNOX2 alleles exhibit impaired differentiation of all aerial organs and have highly complex leaves, phenocopying gain-of-function KNOX1 alleles. Conversely, gain-of-function KNOX2 alleles in conjunction with a presumptive heterodimeric BELL TALE homeobox partner suppressed SAM activity in Arabidopsis and reduced leaf complexity in the Arabidopsis relative Cardamine hirsuta, reminiscent of loss-of-function KNOX1 alleles. Little evidence was found indicative of epistasis or mutual repression between KNOX1 and KNOX2 genes. KNOX proteins heterodimerize with BELL TALE homeobox proteins to form functional complexes, and contrary to earlier reports based on in vitro and heterologous expression, we find high selectivity between KNOX and BELL partners in vivo. Thus, KNOX2 genes confer opposing activities rather than redundant roles with KNOX1 genes, and together they act to direct the development of all above-ground organs of the Arabidopsis sporophyte. We infer that following the KNOX1/KNOX2 gene duplication in an ancestor of land plants, neofunctionalization led to evolution of antagonistic biochemical activity thereby facilitating the evolution of more complex sporophyte transcriptional networks, providing plasticity for the morphological evolution of land plant body plans.
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Affiliation(s)
- Chihiro Furumizu
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - John Paul Alvarez
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Keiko Sakakibara
- School of Biological Sciences, Monash University, Melbourne, Australia
- Graduate School of Science, University of Tokyo, Hongo, Tokyo, Japan
| | - John L. Bowman
- School of Biological Sciences, Monash University, Melbourne, Australia
- Department of Plant Biology, University of California Davis, Davis, California, United States of America
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34
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Plackett ARG, Di Stilio VS, Langdale JA. Ferns: the missing link in shoot evolution and development. FRONTIERS IN PLANT SCIENCE 2015; 6:972. [PMID: 26594222 PMCID: PMC4635223 DOI: 10.3389/fpls.2015.00972] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Accepted: 10/23/2015] [Indexed: 05/02/2023]
Abstract
Shoot development in land plants is a remarkably complex process that gives rise to an extreme diversity of forms. Our current understanding of shoot developmental mechanisms comes almost entirely from studies of angiosperms (flowering plants), the most recently diverged plant lineage. Shoot development in angiosperms is based around a layered multicellular apical meristem that produces lateral organs and/or secondary meristems from populations of founder cells at its periphery. In contrast, non-seed plant shoots develop from either single apical initials or from a small population of morphologically distinct apical cells. Although developmental and molecular information is becoming available for non-flowering plants, such as the model moss Physcomitrella patens, making valid comparisons between highly divergent lineages is extremely challenging. As sister group to the seed plants, the monilophytes (ferns and relatives) represent an excellent phylogenetic midpoint of comparison for unlocking the evolution of shoot developmental mechanisms, and recent technical advances have finally made transgenic analysis possible in the emerging model fern Ceratopteris richardii. This review compares and contrasts our current understanding of shoot development in different land plant lineages with the aim of highlighting the potential role that the fern C. richardii could play in shedding light on the evolution of underlying genetic regulatory mechanisms.
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Affiliation(s)
- Andrew R. G. Plackett
- Department of Plant Sciences, University of OxfordOxford, UK
- *Correspondence: Andrew R. G. Plackett,
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35
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Frank MH, Scanlon MJ. Transcriptomic evidence for the evolution of shoot meristem function in sporophyte-dominant land plants through concerted selection of ancestral gametophytic and sporophytic genetic programs. Mol Biol Evol 2014; 32:355-67. [PMID: 25371433 DOI: 10.1093/molbev/msu303] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Alternation of generations, in which the haploid and diploid stages of the life cycle are each represented by multicellular forms that differ in their morphology, is a defining feature of the land plants (embryophytes). Anciently derived lineages of embryophytes grow predominately in the haploid gametophytic generation from apical cells that give rise to the photosynthetic body of the plant. More recently evolved plant lineages have multicellular shoot apical meristems (SAMs), and photosynthetic shoot development is restricted to the sporophyte generation. The molecular genetic basis for this evolutionary shift from gametophyte-dominant to sporophyte-dominant life cycles remains a major question in the study of land plant evolution. We used laser microdissection and next generation RNA sequencing to address whether angiosperm meristem patterning genes expressed in the sporophytic SAM of Zea mays are expressed in the gametophytic apical cells, or in the determinate sporophytes, of the model bryophytes Marchantia polymorpha and Physcomitrella patens. A wealth of upregulated genes involved in stem cell maintenance and organogenesis are identified in the maize SAM and in both the gametophytic apical cell and sporophyte of moss, but not in Marchantia. Significantly, meiosis-specific genetic programs are expressed in bryophyte sporophytes, long before the onset of sporogenesis. Our data suggest that this upregulated accumulation of meiotic gene transcripts suppresses indeterminate cell fate in the Physcomitrella sporophyte, and overrides the observed accumulation of meristem patterning genes. A model for the evolution of indeterminate growth in the sporophytic generation through the concerted selection of ancestral meristem gene programs from gametophyte-dominant lineages is proposed.
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Plackett AR, Huang L, Sanders HL, Langdale JA. High-efficiency stable transformation of the model fern species Ceratopteris richardii via microparticle bombardment. PLANT PHYSIOLOGY 2014; 165:3-14. [PMID: 24623851 PMCID: PMC4012588 DOI: 10.1104/pp.113.231357] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 03/11/2014] [Indexed: 05/18/2023]
Abstract
Ferns represent the most closely related extant lineage to seed plants. The aquatic fern Ceratopteris richardii has been subject to research for a considerable period of time, but analyses of the genetic programs underpinning developmental processes have been hampered by a large genome size, a lack of available mutants, and an inability to create stable transgenic lines. In this paper, we report a protocol for efficient stable genetic transformation of C. richardii and a closely related species Ceratopteris thalictroides using microparticle bombardment. Indeterminate callus was generated and maintained from the sporophytes of both species using cytokinin treatment. In proof-of-principle experiments, a 35S::β-glucuronidase (GUS) expression cassette was introduced into callus cells via tungsten microparticles, and stable transformants were selected via a linked hygromycin B resistance marker. The presence of the transgene in regenerated plants and in subsequent generations was validated using DNA-blot analysis, reverse transcription-polymerase chain reaction, and GUS staining. GUS staining patterns in most vegetative tissues corresponded with constitutive gene expression. The protocol described in this paper yields transformation efficiencies far greater than those previously published and represents a significant step toward the establishment of a tractable fern genetic model.
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Evkaikina AI, Romanova MA, Voitsekhovskaja OV. Evolutionary aspects of non-cell-autonomous regulation in vascular plants: structural background and models to study. FRONTIERS IN PLANT SCIENCE 2014; 5:31. [PMID: 24575105 PMCID: PMC3920070 DOI: 10.3389/fpls.2014.00031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 01/24/2014] [Indexed: 05/08/2023]
Abstract
Plasmodesmata (PD) serve for the exchange of information in form of miRNA, proteins, and mRNA between adjacent cells in the course of plant development. This fundamental role of PD is well established in angiosperms but has not yet been traced back to the evolutionary ancient plant taxa where functional studies lag behind studies of PD structure and ontogenetic origin. There is convincing evidence that the ability to form secondary (post-cytokinesis) PD, which can connect any adjacent cells, contrary to primary PD which form during cytokinesis and link only cells of the same lineage, appeared in the evolution of higher plants at least twice: in seed plants and in some representatives of the Lycopodiophyta. The (in)ability to form secondary PD is manifested in the symplasmic organization of the shoot apical meristem (SAM) which in most taxa of seedless vascular plants differs dramatically from that in seed plants. Lycopodiophyta appear to be suitable models to analyze the transport of developmental regulators via PD in SAMs with symplasmic organization both different from, as well as analogous to, that in angiosperms, and to understand the evolutionary aspects of the role of this transport in the morphogenesis of vascular plant taxa.
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Affiliation(s)
- Anastasiia I. Evkaikina
- Laboratory of Plant Ecological Physiology, Komarov Botanical Institute, Russian Academy of SciencesSaint Petersburg, Russia
| | - Marina A. Romanova
- Department of Botany, Saint Petersburg State UniversitySaint Petersburg, Russia
| | - Olga V. Voitsekhovskaja
- Laboratory of Plant Ecological Physiology, Komarov Botanical Institute, Russian Academy of SciencesSaint Petersburg, Russia
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38
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Vasco A, Moran RC, Ambrose BA. The evolution, morphology, and development of fern leaves. FRONTIERS IN PLANT SCIENCE 2013; 4:345. [PMID: 24027574 PMCID: PMC3761161 DOI: 10.3389/fpls.2013.00345] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 08/15/2013] [Indexed: 05/18/2023]
Abstract
Leaves are lateral determinate structures formed in a predictable sequence (phyllotaxy) on the flanks of an indeterminate shoot apical meristem. The origin and evolution of leaves in vascular plants has been widely debated. Being the main conspicuous organ of nearly all vascular plants and often easy to recognize as such, it seems surprising that leaves have had multiple origins. For decades, morphologists, anatomists, paleobotanists, and systematists have contributed data to this debate. More recently, molecular genetic studies have provided insight into leaf evolution and development mainly within angiosperms and, to a lesser extent, lycophytes. There has been recent interest in extending leaf evolutionary developmental studies to other species and lineages, particularly in lycophytes and ferns. Therefore, a review of fern leaf morphology, evolution and development is timely. Here we discuss the theories of leaf evolution in ferns, morphology, and diversity of fern leaves, and experimental results of fern leaf development. We summarize what is known about the molecular genetics of fern leaf development and what future studies might tell us about the evolution of fern leaf development.
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Affiliation(s)
| | | | - Barbara A. Ambrose
- *Correspondence: Barbara A. Ambrose, The New York Botanical Garden, 2900 Southern Blvd., Bronx, NY 10458-5126, USA e-mail:
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39
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Stammler A, Meyer SS, Plant AR, Townsley BT, Becker A, Gleissberg S. Duplicated STM-like KNOX I genes act in floral meristem activity in Eschscholzia californica (Papaveraceae). Dev Genes Evol 2013; 223:289-301. [DOI: 10.1007/s00427-013-0446-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 04/01/2013] [Indexed: 01/06/2023]
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40
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Box MS, Dodsworth S, Rudall PJ, Bateman RM, Glover BJ. Flower-specific KNOX phenotype in the orchid Dactylorhiza fuchsii. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:4811-9. [PMID: 22771852 PMCID: PMC3428008 DOI: 10.1093/jxb/ers152] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The KNOTTED1-like homeobox (KNOX) genes are best known for maintaining a pluripotent stem-cell population in the shoot apical meristem that underlies indeterminate vegetative growth, allowing plants to adapt their development to suit the prevailing environmental conditions. More recently, the function of the KNOX gene family has been expanded to include additional roles in lateral organ development such as complex leaf morphogenesis, which has come to dominate the KNOX literature. Despite several reports implicating KNOX genes in the development of carpels and floral elaborations such as petal spurs, few authors have investigated the role of KNOX genes in flower development. Evidence is presented here of a flower-specific KNOX function in the development of the elaborate flowers of the orchid Dactylorhiza fuchsii, which have a three-lobed labellum petal with a prominent spur. Using degenerate PCR, four Class I KNOX genes (DfKN1-4) have been isolated, one from each of the four major Class I KNOX subclades and by reverse transcription PCR (RT-PCR), it is demonstrated that DfKNOX transcripts are detectable in developing floral organs such as the spur-bearing labellum and inferior ovary. Although constitutive expression of the DfKN2 transcript in tobacco produces a wide range of floral abnormalities, including serrated petal margins, extra petal tissue, and fused organs, none of the vegetative phenotypes typical of constitutive KNOX expression were produced. These data are highly suggestive of a role for KNOX expression in floral development that may be especially important in taxa with elaborate flowers.
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Affiliation(s)
- Mathew S. Box
- Department of Plant Sciences, University of CambridgeDowning Street, Cambridge CB2 3EA, UK
| | - Steven Dodsworth
- Department of Plant Sciences, University of CambridgeDowning Street, Cambridge CB2 3EA, UK
| | - Paula J. Rudall
- Jodrell Laboratory, Royal Botanic GardensKew, Richmond, Surrey TW9 3AB, UK
| | - Richard M. Bateman
- Jodrell Laboratory, Royal Botanic GardensKew, Richmond, Surrey TW9 3AB, UK
| | - Beverley J. Glover
- Department of Plant Sciences, University of CambridgeDowning Street, Cambridge CB2 3EA, UK
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41
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Yamaguchi T, Nukazuka A, Tsukaya H. Leaf adaxial-abaxial polarity specification and lamina outgrowth: evolution and development. PLANT & CELL PHYSIOLOGY 2012; 53:1180-94. [PMID: 22619472 DOI: 10.1093/pcp/pcs074] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A key innovation in leaf evolution is the acquisition of a flat lamina with adaxial-abaxial polarity, which optimizes the primary function of photosynthesis. The developmental mechanism behind leaf adaxial-abaxial polarity specification and flat lamina formation has long been of interest to biologists. Surgical and genetic studies proposed a conceptual model wherein a signal derived from the shoot apical meristem is necessary for adaxial-abaxial polarity specification, and subsequent lamina outgrowth is promoted at the juxtaposition of adaxial and abaxial identities. Several distinct regulators involved in leaf adaxial-abaxial polarity specification and lamina outgrowth have been identified. Analyses of these genes demonstrated that the mutual antagonistic interactions between adaxial and abaxial determinants establish polarity and define the boundary between two domains, along which lamina outgrowth regulators function. Evolutionary developmental studies on diverse leaf forms of angiosperms proposed that alteration to the adaxial-abaxial patterning system can be a major driving force in the generation of diverse leaf forms, as represented by 'unifacial leaves', in which leaf blades have only the abaxial identity. Interestingly, unifacial leaf blades become flattened, in spite of the lack of adaxial-abaxial juxtaposition. Modification of the adaxial-abaxial patterning system is also utilized to generate complex organ morphologies, such as stamens. In this review, we summarize recent advances in the genetic mechanisms underlying leaf adaxial-abaxial polarity specification and lamina outgrowth, with emphasis on the genetic basis of the evolution and diversification of leaves.
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Affiliation(s)
- Takahiro Yamaguchi
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
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42
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Ligrone R, Duckett JG, Renzaglia KS. Major transitions in the evolution of early land plants: a bryological perspective. ANNALS OF BOTANY 2012; 109:851-71. [PMID: 22356739 PMCID: PMC3310499 DOI: 10.1093/aob/mcs017] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 01/06/2012] [Indexed: 05/02/2023]
Abstract
Background Molecular phylogeny has resolved the liverworts as the earliest-divergent clade of land plants and mosses as the sister group to hornworts plus tracheophytes, with alternative topologies resolving the hornworts as sister to mosses plus tracheophytes less well supported. The tracheophytes plus fossil plants putatively lacking lignified vascular tissue form the polysporangiophyte clade. Scope This paper reviews phylogenetic, developmental, anatomical, genetic and paleontological data with the aim of reconstructing the succession of events that shaped major land plant lineages. Conclusions Fundamental land plant characters primarily evolved in the bryophyte grade, and hence the key to a better understanding of the early evolution of land plants is in bryophytes. The last common ancestor of land plants was probably a leafless axial gametophyte bearing simple unisporangiate sporophytes. Water-conducting tissue, if present, was restricted to the gametophyte and presumably consisted of perforate cells similar to those in the early-divergent bryophytes Haplomitrium and Takakia. Stomata were a sporophyte innovation with the possible ancestral functions of producing a transpiration-driven flow of water and solutes from the parental gametophyte and facilitating spore separation before release. Stomata in mosses, hornworts and polysporangiophytes are viewed as homologous, and hence these three lineages are collectively referred to as the 'stomatophytes'. An indeterminate sporophyte body (the sporophyte shoot) developing from an apical meristem was the key innovation in polysporangiophytes. Poikilohydry is the ancestral condition in land plants; homoiohydry evolved in the sporophyte of polysporangiophytes. Fungal symbiotic associations ancestral to modern arbuscular mycorrhizas evolved in the gametophytic generation before the separation of major present-living lineages. Hydroids are imperforate water-conducting cells specific to advanced mosses. Xylem vascular cells in polysporangiophytes arose either from perforate cells or de novo. Food-conducting cells were a very early innovation in land plant evolution. The inferences presented here await testing by molecular genetics.
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Affiliation(s)
- Roberto Ligrone
- Dipartimento di Scienze ambientali, Seconda Università di Napoli, via Vivaldi 43, Caserta, Italy.
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43
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Pires ND, Dolan L. Morphological evolution in land plants: new designs with old genes. Philos Trans R Soc Lond B Biol Sci 2012; 367:508-18. [PMID: 22232763 PMCID: PMC3248709 DOI: 10.1098/rstb.2011.0252] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The colonization and radiation of multicellular plants on land that started over 470 Ma was one of the defining events in the history of this planet. For the first time, large amounts of primary productivity occurred on the continental surface, paving the way for the evolution of complex terrestrial ecosystems and altering global biogeochemical cycles; increased weathering of continental silicates and organic carbon burial resulted in a 90 per cent reduction in atmospheric carbon dioxide levels. The evolution of plants on land was itself characterized by a series of radical transformations of their body plans that included the formation of three-dimensional tissues, de novo evolution of a multicellular diploid sporophyte generation, evolution of multicellular meristems, and the development of specialized tissues and organ systems such as vasculature, roots, leaves, seeds and flowers. In this review, we discuss the evolution of the genes and developmental mechanisms that drove the explosion of plant morphologies on land. Recent studies indicate that many of the gene families which control development in extant plants were already present in the earliest land plants. This suggests that the evolution of novel morphologies was to a large degree driven by the reassembly and reuse of pre-existing genetic mechanisms.
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Affiliation(s)
| | - Liam Dolan
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
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Sanders HL, Darrah PR, Langdale JA. Sector analysis and predictive modelling reveal iterative shoot-like development in fern fronds. Development 2011; 138:2925-34. [PMID: 21653615 DOI: 10.1242/dev.065888] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Plants colonized the terrestrial environment over 450 million years ago. Since then, shoot architecture has evolved in response to changing environmental conditions. Our current understanding of the innovations that altered shoot morphology is underpinned by developmental studies in a number of plant groups. However, the least is known about mechanisms that operate in ferns--a key group for understanding the evolution of plant development. Using a novel combination of sector analysis, conditional probability modelling methods and histology, we show that shoots, fronds ('leaves') and pinnae ('leaflets') of the fern Nephrolepis exaltata all develop from single apical initial cells. Shoot initials cleave on three faces to produce a pool of cells from which individual frond apical initials are sequentially specified. Frond initials then cleave in two planes to produce a series of lateral merophyte initials that each contributes a unit of three pinnae to half of the mediolateral frond axis. Notably, this iterative pattern in both shoots and fronds is similar to the developmental process that operates in shoots of other plant groups. Pinnae initials first cleave in two planes to generate lateral marginal initials. The apical and marginal initials then divide in three planes to coordinately generate the determinate pinna. These findings impact both on our understanding of fundamental plant developmental processes and on our perspective of how shoot systems evolved.
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Affiliation(s)
- Heather L Sanders
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, UK
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45
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Shaw AJ, Szövényi P, Shaw B. Bryophyte diversity and evolution: windows into the early evolution of land plants. AMERICAN JOURNAL OF BOTANY 2011; 98:352-69. [PMID: 21613131 DOI: 10.3732/ajb.1000316] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The "bryophytes" comprise three phyla of plants united by a similar haploid-dominant life cycle and unbranched sporophytes bearing one sporangium: the liverworts (Marchantiophyta), mosses (Bryophyta), and hornworts (Anthocerophyta). Combined, these groups include some 20000 species. As descendents of embryophytes that diverged before tracheophytes appeared, bryophytes offer unique windows into the early evolution of land plants. We review insights into the evolution of plant life cycles, in particular the elaboration of the sporophyte generation, the major lineages within bryophyte phyla, and reproductive processes that shape patterns of bryophyte evolution. Recent transcriptomic work suggests extensive overlap in gene expression in bryophyte sporophytes vs. gametophytes, but also novel patterns in the sporophyte, supporting Bower's antithetic hypothesis for origin of alternation of generations. Major lineages of liverworts, mosses, and hornworts have been resolved and general patterns of morphological evolution can now be inferred. The life cycles of bryophytes, arguably more similar to those of early embryophytes than are those in any other living plant group, provide unique insights into gametophyte mating patterns, sexual conflicts, and the efficacy and effects of spore dispersal during early land plant evolution.
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Affiliation(s)
- A Jonathan Shaw
- Department of Biology, Duke University, Durham, North Carolina 27708, USA.
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46
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Hay A, Tsiantis M. KNOX genes: versatile regulators of plant development and diversity. Development 2010; 137:3153-65. [PMID: 20823061 DOI: 10.1242/dev.030049] [Citation(s) in RCA: 357] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Knotted1-like homeobox (KNOX) proteins are homeodomain transcription factors that maintain an important pluripotent cell population called the shoot apical meristem, which generates the entire above-ground body of vascular plants. KNOX proteins regulate target genes that control hormone homeostasis in the meristem and interact with another subclass of homeodomain proteins called the BELL family. Studies in novel genetic systems, both at the base of the land plant phylogeny and in flowering plants, have uncovered novel roles for KNOX proteins in sculpting plant form and its diversity. Here, we discuss how KNOX proteins influence plant growth and development in a versatile context-dependent manner.
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Affiliation(s)
- Angela Hay
- Plant Sciences Department, University of Oxford, Oxford, UK.
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47
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Szovenyi P, Rensing SA, Lang D, Wray GA, Shaw AJ. Generation-Biased Gene Expression in a Bryophyte Model System. Mol Biol Evol 2010; 28:803-12. [DOI: 10.1093/molbev/msq254] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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48
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Montero-Córtes M, Sáenz L, Córdova I, Quiroz A, Verdeil JL, Oropeza C. GA3 stimulates the formation and germination of somatic embryos and the expression of a KNOTTED-like homeobox gene of Cocos nucifera (L.). PLANT CELL REPORTS 2010; 29:1049-59. [PMID: 20582418 DOI: 10.1007/s00299-010-0890-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 06/08/2010] [Accepted: 06/15/2010] [Indexed: 05/13/2023]
Abstract
The micropropagation of coconut palm has progressed rapidly; yet, there are constraints with regard to the number of somatic embryos formed and their germination. To overcome these, we tested the effect of gibberellic acid and characterized genes of the KNOX family. Gibberellic acid at 0.5 muM increased 1.5-fold the number of calli forming somatic embryos and twofold the number of somatic embryos per callus, calli with germinating embryos and the number of germinating somatic embryos per callus. With regard to the study of KNOX family genes, the complete sequences of two KNOX-like genes were obtained for CnKNOX1 and CnKNOX2. The deduced amino acid sequence of both showed highly conserved domains characteristic of KNOX genes. CnKNOX1 showed high homology with KNOX class I proteins. CnKNOX1 expression was detected throughout the embryogenesis process except in somatic embryos at the pro-globular stage, and was highest in somatic embryos at the coleoptilar stage. No detection of CnKNOX1 expression occurred in calli with aberrant embryos. The addition of gibberellic acid stimulated the expression of CnKNOX1 earlier and the relative expression at all stages was higher. CnKNOX2 expression occurred at all stages peaking at the globular stage, but gibberellic acid treatment decreased the expression. Gene expression was also analyzed in tissues of different organs of adult palms. With CnKNOX1, high level of expression was found in tissues of organs with, but not in those without, meristem, whereas CnKNOX2 expression was detected in tissues with and also in those without meristem.
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Affiliation(s)
- M Montero-Córtes
- Centro de Investigación Científica de Yucatán, Biotechnology Unit, Calle 43 No. 130, Colonia Chuburna de Hidalgo, 97200, Mérida, Yucatán, Mexico
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49
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Harrison CJ, Alvey E, Henderson IR. Meiosis in flowering plants and other green organisms. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:2863-75. [PMID: 20576791 DOI: 10.1093/jxb/erq191] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Sexual eukaryotes generate gametes using a specialized cell division called meiosis that serves both to halve the number of chromosomes and to reshuffle genetic variation present in the parent. The nature and mechanism of the meiotic cell division in plants and its effect on genetic variation are reviewed here. As flowers are the site of meiosis and fertilization in angiosperms, meiotic control will be considered within this developmental context. Finally, we review what is known about the control of meiosis in green algae and non-flowering land plants and discuss evolutionary transitions relating to meiosis that have occurred in the lineages giving rise to the angiosperms.
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Affiliation(s)
- C Jill Harrison
- Department of Plant Sciences, University of Cambridge, Cambridge, UK.
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50
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Floyd SK, Bowman JL. Gene expression patterns in seed plant shoot meristems and leaves: homoplasy or homology? JOURNAL OF PLANT RESEARCH 2010; 123:43-55. [PMID: 19784716 DOI: 10.1007/s10265-009-0256-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Accepted: 07/06/2009] [Indexed: 05/08/2023]
Abstract
The fossil record reveals that seed plant leaves evolved from ancestral lateral branch systems. Over time, the lateral branch systems evolved to become determinate, planar and eventually laminar. Considering their evolutionary histories, it is instructive to compare the developmental genetics of shoot apical meristems (SAMs) and leaves in extant seed plants. Genetic experiments in model angiosperm species have assigned functions of meristem maintenance, specification of stem cell identity, boundary formation, polarity establishment and primordium initiation to specific genes. Investigation of roles of the same or homologous genes during leaf development has revealed strikingly similar functions in leaves compared to SAMs. Specifically, the marginal blastozone that characterizes many angiosperm leaves appears to function in a manner mechanistically similar to the SAM. We argue here that the similarities may be homologous due to descent from ancestral roles in an ancestral shoot system. Molecular aspects of SAM and leaf development in gymnosperms is largely neglected and could provide insight into seed plant leaf evolution.
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