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Fu Q, Sun J, Zheng S, Wang X. Unique Jurassic Ovaries Shed a New Light on the Nature of Carpels. PLANTS (BASEL, SWITZERLAND) 2024; 13:2239. [PMID: 39204675 PMCID: PMC11360278 DOI: 10.3390/plants13162239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 08/02/2024] [Accepted: 08/07/2024] [Indexed: 09/04/2024]
Abstract
Enclosed ovules are a reproductive feature restricted to angiosperms. Although this feature can be used as a criterion for identifying fossil angiosperms, how ovules are enclosed and the nature of the placenta are still foci of debates. A reason underlying these controversies is the lack of reproductive organ fossils shedding light on these issues. These controversies hinder a clear understanding of angiosperm evolution and systematics. Here, we report a new fossil ovary, Xenofructus dabuensis gen. et sp. nov, from the Middle Jurassic of Liaoning, China. Our fossil clearly demonstrates the existence of ovules in Xenofructus that has a free central placentation. This new feature implies that a placenta in angiosperm gynoecia is homologous to an ovule/seed-bearing axis, and free central placentation is one of the early developed placentations. This discovery is apparently at odds with the current understanding of placentation and its evolution. Apparently, the understanding of angiosperms and their gynoecia should be updated with newly available palaeobotanical data.
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Affiliation(s)
- Qiang Fu
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and CAS Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, China;
- University of Chinese Academy of Sciences (UCAS), Nanjing 211135, China
| | - Jie Sun
- Shaanxi Key Laboratory of Early Life and Environments, State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi’an 710069, China;
| | - Shaolin Zheng
- The Shenyang Center of Geological Survey and Institute of Geology and Mineral Resources, Ministry of National Land and Resources, Shenyang 110034, China
| | - Xin Wang
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and CAS Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, China;
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2
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Liu W, Xu X, Wang X. Unique Morphology of Sarcobatus baileyi Male Inflorescence and Its Botanical Implications. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12091917. [PMID: 37176975 PMCID: PMC10180837 DOI: 10.3390/plants12091917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/28/2023] [Accepted: 05/02/2023] [Indexed: 05/15/2023]
Abstract
A typical angiosperm flower is usually bisexual, with entomophilous plants having four whorls of organs: the calyx, corolla, stamens, and gynoecium. The flower is usually colorful, and thus, distinct from the dull-colored reproductive organs of gymnosperms; however, this formula is not applicable to all flowers. For example, the male flower of Sarcobatus baileyi is reduced into only a single stamen. Such unusual flowers are largely poorly documented and underappreciated. To fill such a lacuna in our knowledge of the male reproductive organ of S. baileyi, we collected and studied materials of the male inflorescence of S. baileyi (Sarcobataceae). The outcomes of our Micro-CT (micro computed tomography), SEM (scanning electron microscopy), and paraffin sectioning indicate that a male inflorescence of S. baileyi is more comparable with the cone of conifers; its male flowers lack the perianth, are directly attached to a central axis and sheltered by peltate indusium-like shields. To understand the evolutionary logic underlying such a rarely seen male inflorescence, we also studied and compared it with a female cone of Cupressus sempervirens. Although the genera Sarcobatus and Cupressus belong to two distinct major plant groups (angiosperms and gymnosperms), they apply the same propagule-protecting strategy.
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Affiliation(s)
- Wenzhe Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), School of Life Sciences, Northwest University, Xi'an 710069, China
| | - Xiuping Xu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Xin Wang
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and CAS Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, China
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3
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Han L, Zhao Y, Zhao M, Sun J, Sun B, Wang X. New Fossil Evidence Suggests That Angiosperms Flourished in the Middle Jurassic. Life (Basel) 2023; 13:life13030819. [PMID: 36983974 PMCID: PMC10059865 DOI: 10.3390/life13030819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 03/14/2023] [Accepted: 03/15/2023] [Indexed: 03/30/2023] Open
Abstract
Angiosperms are a group of plants with the highest rate of evolution, the largest number of species, the widest distribution and the strongest adaptability. Needless to say, angiosperms are the most important group for the humans. The studies on the origin, evolution and systematics of angiosperms have been the major challenges in plant sciences. However, the origin and early history of angiosperms remains poorly understood and controversial among paleobotanists. Some paleobotanists insist that there were no angiosperms in the pre-Cretaceous age. However, this conclusion is facing increasing challenges from fossil evidence, especially Early Jurassic Nanjinganthus, which is based on over two hundred specimens of fossil flowers. Studying more fossil plants is the only reliable way to elucidate the origin and early evolution of angiosperms. Here, we document a new species of angiosperms, Qingganninginfructus formosa gen. et sp. nov, and provide the first detailed three-dimensional morphology of Qingganninginfructus gen. nov from the Middle Jurassic of Northwest China. A Micro-CT examination shows that the best-preserved fossil infructescence has eleven samaroid fruits, each with a single basal ovule. Since these fossils are distinct in morphology and organization from all organs of known gymnosperms and angiosperms (the latter are defined by their enclosed ovules), we interpret Qingganninginfructus as a new genus of angiosperms including a new species, Q. formosa gen. et sp. nov., and an unspecified species from the Middle Jurassic of Northwest China. The discovery of this new genus of angiosperms from the Middle Jurassic, in addition to the existing records, undermines the "no angiosperms until the Cretaceous" stereotype and updates the perspective on the origin and early history of angiosperms.
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Affiliation(s)
- Lei Han
- Key Laboratory of Minerals Resources in Western China (Gansu Province), School of Earth Sciences, Lanzhou University, Lanzhou 730000, China
| | - Ya Zhao
- Ningxia Geological Museum, 301 Eastern People's Square Street, Yinchuan 750000, China
| | - Ming Zhao
- Ningxia Geological Museum, 301 Eastern People's Square Street, Yinchuan 750000, China
| | - Jie Sun
- Shaanxi Key Laboratory of Early Life and Environments, State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China
| | - Bainian Sun
- Key Laboratory of Minerals Resources in Western China (Gansu Province), School of Earth Sciences, Lanzhou University, Lanzhou 730000, China
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, CAS Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, China
| | - Xin Wang
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, CAS Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, China
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4
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Fu Q, Hou Y, Yin P, Diez JB, Pole M, García-Ávila M, Wang X. Micro-CT results exhibit ovules enclosed in the ovaries of Nanjinganthus. Sci Rep 2023; 13:426. [PMID: 36624144 PMCID: PMC9829905 DOI: 10.1038/s41598-022-27334-0] [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: 08/14/2022] [Accepted: 12/30/2022] [Indexed: 01/11/2023] Open
Abstract
The Early Jurassic angiosperm Nanjinganthus has triggered a heated debate among botanists, partially due to the fact that the enclosed ovules were visible to naked eyes only when the ovary is broken but not visible when the closed ovary is intact. Although traditional technologies cannot confirm the existence of ovules in a closed ovary, newly available Micro-CT can non-destructively reveal internal features of fossil plants. Here, we performed Micro-CT observations on three dimensionally preserved coalified compressions of Nanjinganthus. Our outcomes corroborate the conclusion given by Fu et al., namely, that Nanjinganthus is an Early Jurassic angiosperm.
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Affiliation(s)
- Qiang Fu
- grid.9227.e0000000119573309State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and CAS Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, 210008 China
| | - Yemao Hou
- grid.9227.e0000000119573309Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, CAS Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, 100044 China
| | - Pengfei Yin
- grid.9227.e0000000119573309Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, CAS Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, 100044 China
| | - José Bienvenido Diez
- grid.6312.60000 0001 2097 6738Departamento de Xeociencias Mariñas e Ordenación do Territorio, Universidade de Vigo, 36200 Vigo, Spain ,grid.6312.60000 0001 2097 6738Centro de Investigación Mariña, Universidade de Vigo (CIM-UVIGO), 36200 Vigo, Spain
| | - Mike Pole
- Queensland Herbarium, Mount Coot-Tha Road, Toowong, QLD 4066 Australia
| | - Manuel García-Ávila
- grid.6312.60000 0001 2097 6738Departamento de Xeociencias Mariñas e Ordenación do Territorio, Universidade de Vigo, 36200 Vigo, Spain ,grid.6312.60000 0001 2097 6738Centro de Investigación Mariña, Universidade de Vigo (CIM-UVIGO), 36200 Vigo, Spain
| | - Xin Wang
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and CAS Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, 210008, China.
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5
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Sokoloff DD, Remizowa MV, El ES, Rudall PJ, Bateman RM. Supposed Jurassic angiosperms lack pentamery, an important angiosperm-specific feature. THE NEW PHYTOLOGIST 2020; 228:420-426. [PMID: 31418869 DOI: 10.1111/nph.15974] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 05/24/2019] [Indexed: 06/10/2023]
Affiliation(s)
- Dmitry D Sokoloff
- Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Margarita V Remizowa
- Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Elena S El
- Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, 119234, Russia
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6
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Coiro M, Doyle JA, Hilton J. How deep is the conflict between molecular and fossil evidence on the age of angiosperms? THE NEW PHYTOLOGIST 2019; 223:83-99. [PMID: 30681148 DOI: 10.1111/nph.15708] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/04/2019] [Indexed: 05/06/2023]
Abstract
The timing of the origin of angiosperms is a hotly debated topic in plant evolution. Molecular dating analyses that consistently retrieve pre-Cretaceous ages for crown-group angiosperms have eroded confidence in the fossil record, which indicates a radiation and possibly also origin in the Early Cretaceous. Here, we evaluate paleobotanical evidence on the age of the angiosperms, showing how fossils provide crucial data for clarifying the situation. Pollen floras document a Northern Gondwanan appearance of monosulcate angiosperms in the Valanginian and subsequent poleward spread of monosulcates and tricolpate eudicots, accelerating in the Albian. The sequence of pollen types agrees with molecular phylogenetic inferences on the course of pollen evolution, but it conflicts strongly with Triassic and early Jurassic molecular ages, and the discrepancy is difficult to explain by geographic or taphonomic biases. Critical scrutiny shows that supposed pre-Cretaceous angiosperms either represent other plant groups or lack features that might confidently assign them to the angiosperms. However, the record may allow the Late Jurassic existence of ecologically restricted angiosperms, like those seen in the basal ANITA grade. Finally, we examine recently recognized biases in molecular dating and argue that a thoughtful integration of fossil and molecular evidence could help resolve these conflicts.
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Affiliation(s)
- Mario Coiro
- Department of Systematic and Evolutionary Botany, University of Zurich, 8008, Zurich, Switzerland
| | - James A Doyle
- Department of Evolution and Ecology, University of California, Davis, CA, 95616, USA
| | - Jason Hilton
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
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7
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Fu Q, Diez JB, Pole M, García Ávila M, Liu ZJ, Chu H, Hou Y, Yin P, Zhang GQ, Du K, Wang X. An unexpected noncarpellate epigynous flower from the Jurassic of China. eLife 2018; 7:38827. [PMID: 30558712 PMCID: PMC6298773 DOI: 10.7554/elife.38827] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 11/04/2018] [Indexed: 11/28/2022] Open
Abstract
The origin of angiosperms has been a long-standing botanical debate. The great diversity of angiosperms in the Early Cretaceous makes the Jurassic a promising period in which to anticipate the origins of the angiosperms. Here, based on observations of 264 specimens of 198 individual flowers preserved on 34 slabs in various states and orientations, from the South Xiangshan Formation (Early Jurassic) of China, we describe a fossil flower, Nanjinganthus dendrostyla gen. et sp. nov.. The large number of specimens and various preservations allow for an evidence-based reconstruction of the flower. From the evidence of the combination of an invaginated receptacle and ovarian roof, we infer that the seeds of Nanjinganthus were completely enclosed. Evidence of an actinomorphic flower with a dendroid style, cup-form receptacle, and angiospermy, is consistent with Nanjinganthus being a bona fide angiosperm from the Jurassic, an inference that we hope will re-invigorate research into angiosperm origins. From oranges to apples, flowering plants produce most of the fruits and vegetables that we can see on display in a supermarket. While we may take little notice of the poppy fields and plum blossoms around us, how flowers came to be has been an intensely debated mystery. The current understanding, which is mainly based on previously available fossils, is that flowers appeared about 125 million years ago in the Cretaceous, an era during which many insects such as bees also emerged. But not everybody agrees that this is the case. Genetic analyses, for example, suggest that flowering plants are much more ancient. Another intriguing element is that flowers seemed to have arisen during the Cretaceous ‘out of nowhere’. Fossils are essential to help settle the debate but it takes diligence and luck to find something as fragile as a flower preserved in rocks for millions of years. In addition, digging out what could look like a bloom is not enough. It is only if the ovules (the cells that will become seeds when fertilized) of the plant are completely enclosed inside the ovary before pollination that researchers can definitely say that they have found a ‘true’ flower. Now, Fu et al. describe over 200 specimens of a new fossil flower that presents this characteristic, as well as other distinctive features such as petals and sepals – the leaf-like parts that protect a flower bud. Called Nanjinganthus, the plant dates back to more than 174 million years ago, making it the oldest known record of a ‘true’ flower by almost 50 million years. Contrary to mainstream belief, this would place the apparition of flowering plants to the Early Jurassic, the period that saw dinosaurs dominating the planet. This discovery may reshape our current understanding of the evolution of flowers.
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Affiliation(s)
- Qiang Fu
- CAS Key Laboratory of Economic Stratigraphy and Paleogeography, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, China
| | | | - Mike Pole
- Queensland Herbarium, Brisbane Botanical Gardens Mt Coot-tha, Toowong, Australia
| | - Manuel García Ávila
- Departamento de Geociencias, Universidad de Vigo, Vigo, Spain.,Facultade de Bioloxía, Asociación Paleontolóxica Galega, Universidade de Vigo, Vigo, Spain
| | - Zhong-Jian Liu
- State Forestry Administration Key Laboratory of Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Hang Chu
- Tianjin Center, China Geological Survey, Tianjin, China
| | - Yemao Hou
- Key Laboratory of Vertebrate Evolution and Human Origin of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
| | - Pengfei Yin
- Key Laboratory of Vertebrate Evolution and Human Origin of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
| | - Guo-Qiang Zhang
- State Forestry Administration Key Laboratory of Orchid Conservation and Utilization at College of Landscape Architecture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Kaihe Du
- Jiangsu Key Laboratory for Supramolecular Medicinal Materials and Applications, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Xin Wang
- CAS Key Laboratory of Economic Stratigraphy and Paleogeography, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, China
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8
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Liu ZJ, Wang X. Yuhania: a unique angiosperm from the Middle Jurassic of Inner Mongolia, China. HISTORICAL BIOLOGY 2017; 29:431-441. [PMID: 28392623 PMCID: PMC5359780 DOI: 10.1080/08912963.2016.1178740] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 04/12/2016] [Indexed: 05/10/2023]
Abstract
Despite increasing claims of pre-Cretaceous angiosperms, whether there really are angiosperms in the Jurassic is apparently still an open question for many people before further evidence is available. This question can only be answered by studying more Jurassic plant fossils. Here we report a fossil angiosperm, Yuhania daohugouensis gen. et sp. nov, from the Middle Jurassic of Inner Mongolia, China. The plant includes connected stem, leaves, flowers, aggregate fruits, fruitlets, and seeds within fruitlets. The leaves are helically arranged along the curving stem, linear in shape, with 5-6 parallel veins. The aggregate fruit is pedicellate, composed of over 20 carpels/fruitlets helically arranged. Each fruitlet encloses a seed. The reproductive organs in various stages are found in the same plant, allowing us to understand the development of Yuhania. The occurrence of Yuhania in the Middle Jurassic re-confirms the Jurassic history for angiosperms that has been suggested by other independent research and adds to the on-going study on the early evolution of angiosperms.
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Affiliation(s)
- Zhong-Jian Liu
- Shenzhen Key Laboratory for Orchid Conservation and Utilization, National Orchid Conservation Center of China and Orchid Conservation & Research Center of Shenzhen, Shenzhen518114, China
| | - Xin Wang
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, CAS, Nanjing210008, China
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9
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Herendeen PS, Friis EM, Pedersen KR, Crane PR. Palaeobotanical redux: revisiting the age of the angiosperms. NATURE PLANTS 2017; 3:17015. [PMID: 28260783 DOI: 10.1038/nplants.2017.15] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 01/24/2017] [Indexed: 06/06/2023]
Abstract
Angiosperms (flowering plants) are the most diverse of all major lineages of land plants and the dominant autotrophs in most terrestrial ecosystems. Their evolutionary and ecological appearance is therefore of considerable interest and has significant implications for understanding patterns of diversification in other lineages, including insects and other animals. More than half a century ago, influential reviews showed that while angiosperms are richly represented in sediments of Late Cretaceous and younger ages, there are no reliable records of angiosperms from pre-Cretaceous rocks. The extensive new macrofossil, mesofossil, and microfossil data that have accumulated since have confirmed and reinforced this pattern. Recently, however, molecular dating methods have raised the possibility that angiosperms may have existed much earlier, and there have been scattered reports of putative angiosperms from Triassic and Jurassic rocks. Critical assessment of these reports shows that, so far, none provide unequivocal evidence of pre-Cretaceous angiosperms. Angiosperms may ultimately be recognized from Jurassic or earlier rocks, but credible palaeobotanical evidence will require unambiguous documentation of the diagnostic structural features that separate angiosperms from other groups of extant and extinct seed plants.
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Affiliation(s)
| | - Else Marie Friis
- Department of Palaeobiology, Swedish Museum of Natural History, SE-104 05 Stockholm, Sweden
| | | | - Peter R Crane
- Oak Spring Garden Foundation, 1776 Loughborough Lane, Upperville, Virginia 20184, USA
- Yale School of Forestry and Environmental Studies, 195 Prospect Street, New Haven, Connecticut 06511, USA
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11
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Liu ZJ, Wang X. A perfect flower from the Jurassic of China. HISTORICAL BIOLOGY 2016; 28:707-719. [PMID: 27134345 PMCID: PMC4841032 DOI: 10.1080/08912963.2015.1020423] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 02/03/2015] [Accepted: 02/04/2015] [Indexed: 05/10/2023]
Abstract
Flower, enclosed ovule and tetrasporangiate anther are three major characters distinguishing angiosperms from other seed plants. Morphologically, typical flowers are characterised by an organisation with gynoecium and androecium surrounded by corolla and calyx. Theoretically, flowers are derived from their counterparts in ancient ancestral gymnosperms. However, as for when, how and from which groups, there is no consensus among botanists yet. Although angiosperm-like pollen and angiosperms have been claimed in the Triassic and Jurassic, typical flowers with the aforesaid three key characters are still missing in the pre-Cretaceous age, making many interpretations of flower evolution tentative. Thus searching for flower in the pre-Cretaceous has been a tantalising task for palaeobotanists for a long time. Here, we report a typical flower, Euanthus paniigen. et sp. nov., from the Middle-Late Jurassic of Liaoning, China. Euanthus has sepals, petals, androecium with tetrasporangiate dithecate anthers and gynoecium with enclosed ovules, organised just like in perfect flowers of extant angiosperms. The discovery of Euanthus implies that typical angiosperm flowers have already been in place in the Jurassic, and provides a new insight unavailable otherwise for the evolution of flowers.
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Affiliation(s)
- Zhong-Jian Liu
- Shenzhen Key Laboratory for Orchid Conservation and Utilization, National Orchid Conservation Center of China and Orchid Conservation and Research Center of Shenzhen, Shenzhen518114, P.R. China
| | - Xin Wang
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Nanjing210008, P.R. China
- Palaeontological Center, Bohai University, Jinzhou121013, P.R. China
- Corresponding author.
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12
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Rothwell GW, Stockey RA. Phylogenetic diversification of Early Cretaceous seed plants: The compound seed cone of Doylea tetrahedrasperma. AMERICAN JOURNAL OF BOTANY 2016; 103:923-937. [PMID: 27208360 DOI: 10.3732/ajb.1600030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 03/07/2016] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY Discovery of cupulate ovules of Doylea tetrahedrasperma within a compact, compound seed cone highlights the rich diversity of fructification morphologies, pollination biologies, postpollination enclosure of seeds, and systematic diversity of Early Cretaceous gymnosperms. METHODS Specimens were studied using the cellulose acetate peel technique, three-dimensional reconstructions (in AVIZO), and morphological phylogenetic analyses (in TNT). KEY RESULTS Doylea tetrahedrasperma has bract/fertile short shoot complexes helically arranged within a compact, compound seed cone. Complexes diverge from the axis as a single unit and separate distally into a free bract tip and two sporophylls. Each sporophyll bears a single, abaxial seed, recurved toward the cone axis, that is enveloped after pollinaton by sporophyll tissue, forming a closed cupule. Ovules are pollinated by bisaccate grains captured by micropylar pollination horns. CONCLUSIONS The unique combination of characters shown by D. tetrahedrasperma includes the presence of cupulate seeds borne in conifer-like compound seed cones, an ovuliferous scale analogue structurally equivalent to the ovulate stalk of Ginkgo biloba, gymnospermous pollination, and nearly complete enclosure of mature seeds. These features characterize the Doyleales ord. nov., clearly distinguish it from the seed fern order Corystospermales, and allow for recognition of another recently described Early Cretaceous seed plant as a second species in genus Doylea. A morphological phylogenetic analysis highlights systematic relationships of the Doyleales ord. nov. and emphasizes the explosive phylogenetic diversification of gymnosperms that was underway at the time when flowering plants may have originated and/or first began to radiate.
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Affiliation(s)
- Gar W Rothwell
- Department of Botany and Plant Pathology, 2082 Cordley Hall, Oregon State University, Corvallis, Oregon 97331, USA Department of Environmental and Plant Biology, Ohio University, Athens, Ohio 45701, USA
| | - Ruth A Stockey
- Department of Botany and Plant Pathology, 2082 Cordley Hall, Oregon State University, Corvallis, Oregon 97331, USA
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13
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Ruhfel BR, Gitzendanner MA, Soltis PS, Soltis DE, Burleigh JG. From algae to angiosperms-inferring the phylogeny of green plants (Viridiplantae) from 360 plastid genomes. BMC Evol Biol 2014; 14:23. [PMID: 24533922 PMCID: PMC3933183 DOI: 10.1186/1471-2148-14-23] [Citation(s) in RCA: 322] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 01/13/2014] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Next-generation sequencing has provided a wealth of plastid genome sequence data from an increasingly diverse set of green plants (Viridiplantae). Although these data have helped resolve the phylogeny of numerous clades (e.g., green algae, angiosperms, and gymnosperms), their utility for inferring relationships across all green plants is uncertain. Viridiplantae originated 700-1500 million years ago and may comprise as many as 500,000 species. This clade represents a major source of photosynthetic carbon and contains an immense diversity of life forms, including some of the smallest and largest eukaryotes. Here we explore the limits and challenges of inferring a comprehensive green plant phylogeny from available complete or nearly complete plastid genome sequence data. RESULTS We assembled protein-coding sequence data for 78 genes from 360 diverse green plant taxa with complete or nearly complete plastid genome sequences available from GenBank. Phylogenetic analyses of the plastid data recovered well-supported backbone relationships and strong support for relationships that were not observed in previous analyses of major subclades within Viridiplantae. However, there also is evidence of systematic error in some analyses. In several instances we obtained strongly supported but conflicting topologies from analyses of nucleotides versus amino acid characters, and the considerable variation in GC content among lineages and within single genomes affected the phylogenetic placement of several taxa. CONCLUSIONS Analyses of the plastid sequence data recovered a strongly supported framework of relationships for green plants. This framework includes: i) the placement of Zygnematophyceace as sister to land plants (Embryophyta), ii) a clade of extant gymnosperms (Acrogymnospermae) with cycads + Ginkgo sister to remaining extant gymnosperms and with gnetophytes (Gnetophyta) sister to non-Pinaceae conifers (Gnecup trees), and iii) within the monilophyte clade (Monilophyta), Equisetales + Psilotales are sister to Marattiales + leptosporangiate ferns. Our analyses also highlight the challenges of using plastid genome sequences in deep-level phylogenomic analyses, and we provide suggestions for future analyses that will likely incorporate plastid genome sequence data for thousands of species. We particularly emphasize the importance of exploring the effects of different partitioning and character coding strategies.
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Affiliation(s)
- Brad R Ruhfel
- Department of Biological Sciences, Eastern Kentucky University, Richmond, KY 40475, USA
| | - Matthew A Gitzendanner
- Department of Biology, University of Florida, Gainesville, FL 32611-8525, USA
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611-7800, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Pamela S Soltis
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611-7800, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Douglas E Soltis
- Department of Biology, University of Florida, Gainesville, FL 32611-8525, USA
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611-7800, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - J Gordon Burleigh
- Department of Biology, University of Florida, Gainesville, FL 32611-8525, USA
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
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Uptake of gold nanoparticles in several rat organs after intraperitoneal administration in vivo: a fluorescence study. BIOMED RESEARCH INTERNATIONAL 2013; 2013:353695. [PMID: 23956977 PMCID: PMC3730147 DOI: 10.1155/2013/353695] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 06/21/2013] [Accepted: 06/22/2013] [Indexed: 11/17/2022]
Abstract
Background. The gold nanoparticles (GNPs) have potential applications in cancer diagnosis and therapy. In an attempt to characterise the potential toxicity or hazards of GNPs as a therapeutic or diagnostic tool, the fluorescence spectra in several rat organs in vivo were measured after intraperitoneal administration of GNPs. Methods. The experimental rats were divided into control and six groups (G1A, G1B, G2A, G2B, G3A, and G3B; G1: 20 nm; G2: 10 nm; G3: 50 nm; A: infusion of GNPs for 3 days; B: infusion of GNPs for 7 days). The fluorescence measurements were investigated in the liver, kidney, heart, and lung organs of rats after intraperitoneal administration of GNPs for periods of 3 and 7 days in vivo. Results. The 10 and 20 nm GNPs exhibited spherical morphology shape, while the 50 nm GNPs exhibited hexagonal shape. A sharp decrease in the fluorescence intensity induced with the larger 50 nm GNPs in the liver, kidney, heart, and lung organs of rats at the exposure duration of 3 and 7 days in vivo compared with the smaller 10 and 20 nm GNPs was observed. Conclusions. The decrease in fluorescence intensity may be attributed to occurrence of strong quenching, decrease in number and surface area of GNPs, and high clearance of GNPs via urine and bile. Moreover, decreasing size may lead to an exponential increase in surface area relative to volume, thus making GNPs surface more reactive on aggregation and to its surrounding biological components. The size, shape, surface area, number, and clearance of GNPs play a key role in toxicity and accumulation in the different rat organs. This study demonstrates that fluorescence peak intensity is particle size and exposure duration dependent. This study suggests that fluorescence intensity can be used as a useful tool for pointing to bioaccumulation and toxicity induced by GNPs in the different rat organs.
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Abdelhalim MAK, Mady MM. Liver uptake of gold nanoparticles after intraperitoneal administration in vivo: a fluorescence study. Lipids Health Dis 2011; 10:195. [PMID: 22040092 PMCID: PMC3219743 DOI: 10.1186/1476-511x-10-195] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 10/31/2011] [Indexed: 11/15/2022] Open
Abstract
Background One particularly exciting field of research involves the use of gold nanoparticles (GNPs) in the detection and treatment of cancer cells in the liver. The detection and treatment of cancer is an area in which the light absorption and emission characteristics of GNPs have become useful. Currently, there are no data available regarding the fluorescence spectra or in vivo accumulation of nanoparticles (NPs) in rat liver after repeated administration. In an attempt to characterise the potential toxicity or hazards of GNPs in therapeutic or diagnostic use, the present study measured fluorescence spectra, bioaccumulation and toxic effects of GNPs at 3 and 7 days following intraperitoneal administration of a 50 μl/day dose of 10, 20 or 50 nm GNPs in rats. Methods The experimental rats were divided into one normal group (Ng) and six experimental groups (G1A, G1B, G2A, G2B, G3A and G3B; G1: 20 nm; G2: 10 nm; G3: 50 nm; A: infusion of GNPs for 3 days; B: infusion of GNPs for 7 days). A 50 μl dose of GNPs (0.1% Au by volume) was administered to the animals via intraperitoneal injection, and fluorescence measurements were used to identify the toxicity and tissue distribution of GNPs in vivo. Seventy healthy male Wistar-Kyoto rats were exposed to GNPs, and tissue distribution and toxicity were evaluated after 3 or 7 days of repeated exposure. Results After administration of 10 and 20 nm GNPs into the experimental rats, two fluorescence peaks were observed at 438 nm and 487 nm in the digested liver tissue. The fluorescence intensity for 10 and 20 nm GNPs (both first and second peaks) increased with the infusion time of GNPs in test rats compared to normal rats. The position of the first peak was similar for G1A, G2A, G1B, G2B, G3B and the normal (438 nm); that for G3A was shifted to a longer wavelength (444 nm) compared to the normal. The position of the second peak was similar for G1A, G1B, G2A, G2B and the control (487 nm), while it was shifted to a shorter wavelength for G3A (483 nm) and G3B (483 nm). The fluorescence intensity of the first and second peaks increased for G1A, G2A, G1B and G2B, while it decreased for G3A and G3B compared to the control. Conclusions The fluorescence intensity of GNPs varied with the number, size and shape of particles and with the ratio of surface area to volume in a given sample. Fluorescence intensity changes during infusion depended on the size and shape of GNPs, with smaller particles experiencing larger changes during the infusion time in addition to the quenching produced by the larger GNPs. It is likely that smaller particles, which have a much higher ratio of surface area to volume compared to larger particles, are more prone to aggregation and surface interaction with biological components. This study suggests that fluorescence intensity can be used to evaluate bioaccumulation and the toxicity of gold nanoparticles in rats.
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Affiliation(s)
- Mohamed Anwar K Abdelhalim
- Department of Physics and Astronomy, College of Science, King Saud University, P,O, 2455, Riyadth 11451, Saudi Arabia.
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Abstract
• Plants have utterly transformed the planet, but testing hypotheses of causality requires a reliable time-scale for plant evolution. While clock methods have been extensively developed, less attention has been paid to the correct interpretation and appropriate implementation of fossil data. • We constructed 17 calibrations, consisting of minimum constraints and soft maximum constraints, for divergences between model representatives of the major land plant lineages. Using a data set of seven plastid genes, we performed a cross-validation analysis to determine the consistency of the calibrations. Six molecular clock analyses were then conducted, one with the original calibrations, and others exploring the impact on divergence estimates of changing maxima at basal nodes, and prior probability densities within calibrations. • Cross-validation highlighted Tracheophyta and Euphyllophyta calibrations as inconsistent, either because their soft maxima were overly conservative or because of undetected rate variation. Molecular clock analyses yielded estimates ranging from 568-815 million yr before present (Ma) for crown embryophytes and from 175-240 Ma for crown angiosperms. • We reject both a post-Jurassic origin of angiosperms and a post-Cambrian origin of land plants. Our analyses also suggest that the establishment of the major embryophyte lineages occurred at a much slower tempo than suggested in most previous studies. These conclusions are entirely compatible with current palaeobotanical data, although not necessarily with their interpretation by palaeobotanists.
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Affiliation(s)
- John T Clarke
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
- Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK
| | - Rachel C M Warnock
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
| | - Philip C J Donoghue
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
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WANG X. Schmeissneria: An angiosperm from the Early Jurassic. JOURNAL OF SYSTEMATICS AND EVOLUTION 2010. [PMID: 0 DOI: 10.1111/j.1759-6831.2010.00090.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
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Abstract
The evolution of the seed represents a remarkable life-history transition for photosynthetic organisms. Here, we review the recent literature and historical understanding of how and why seeds evolved. Answering the 'how' question involves a detailed understanding of the developmental morphology and anatomy of seeds, as well as the genetic programs that determine seed size. We complement this with a special emphasis on the evolution of dormancy, the characteristic of seeds that allows for long 'distance' time travel. Answering the 'why' question involves proposed hypotheses of how natural selection has operated to favor the seed life-history phenomenon. The recent flurry of research describing the comparative biology of seeds is discussed. The review will be divided into sections dealing with: (1) the development and anatomy of seeds; (2) the endosperm; (3) dormancy; (4) early seed-like structures and the transition to seeds; and (5) the evolution of seed size (mass). In many cases, a special distinction is made between angiosperm and gymnosperm seeds. Finally, we make some recommendations for future research in seed biology.
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Affiliation(s)
- Ada Linkies
- Botany/Plant Physiology, Institute for Biology II, Faculty of Biology, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany (http://www.seedbiology.de)
| | - Kai Graeber
- Botany/Plant Physiology, Institute for Biology II, Faculty of Biology, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany (http://www.seedbiology.de)
| | - Charles Knight
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93401, USA
| | - Gerhard Leubner-Metzger
- Botany/Plant Physiology, Institute for Biology II, Faculty of Biology, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany (http://www.seedbiology.de)
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Wang X, Zheng S. The earliest normal flower from Liaoning Province, China. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2009; 51:800-11. [PMID: 19686377 DOI: 10.1111/j.1744-7909.2009.00838.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The early evolution of angiosperms has been a focus of intensive research for more than a century. The Yixian Formation in western Liaoning yields one of the earliest angiosperm macrofloras. Despite multitudes of angiosperm fossils uncovered, including Archaefructus and Sinocarpus, no bona fide normal flower has been dated to 125 Ma (mega-annum) or older. Here we report Callianthus dilae gen. et sp. nov. from the Yixian Formation (Early Cretaceous) in western Liaoning, China as the earliest normal flower known to date. The flower demonstrates a typical floral organization, including tepals, androecium, and gynoecium. The tepals are spatulate with parallel veins. The stamens have a slender filament, a globular anther, bristles at the anther apex, and in situ round-triangular pollen grains. The gynoecium is composed of two stylate carpels enclosed in a fleshy envelope, and develops into a "hip" when mature. Since the well-accepted history of angiosperms is not much longer than 125 Ma, Callianthus together with Chaoyangia, Archaefructus and Sinocarpus from the Yixian Formation demonstrate a surprisingly high diversity of angiosperms, implying a history of angiosperms much longer than currently accepted.
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Affiliation(s)
- Xin Wang
- Nanjing Institute of Geology and Palaeontology, the Chinese Academy of Sciences, Nanjing, China.
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Tsunewaki K, Matsuoka Y, Yamazaki Y, Ogihara Y. Evolutionary dynamics of wheat mitochondrial gene structure with special remarks on the origin and effects of RNA editing in cereals. Genes Genet Syst 2008; 83:301-20. [PMID: 18931456 DOI: 10.1266/ggs.83.301] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We investigated the evolutionary dynamics of wheat mitochondrial genes with respect to their structural differentiation during organellar evolution, and to mutations that occurred during cereal evolution. First, we compared the nucleotide sequences of three wheat mitochondrial genes to those of wheat chloroplast, alpha-proteobacterium and cyanobacterium orthologs. As a result, we were able to (1) differentiate the conserved and variable segments of the orthologs, (2) reveal the functional importance of the conserved segments, and (3) provide a corroborative support for the alpha-proteobacterial and cyanobacterial origins of those mitochondrial and chloroplast genes, respectively. Second, we compared the nucleotide sequences of wheat mitochondrial genes to those of rice and maize to determine the types and frequencies of base changes and indels occurred in cereal evolution. Our analyses showed that both the evolutionary speed, in terms of number of base substitutions per site, and the transition/transversion ratio of the cereal mitochondrial genes were less than two-fifths of those of the chloroplast genes. Eight mitochondrial gene groups differed in their evolutionary variability, RNA and Complex I (nad) genes being most stable whereas Complex V (atp) and ribosomal protein genes most variable. C-to-T transition was the most frequent type of base change; C-to-G and G-to-C transversions occurred at lower rates than all other changes. The excess of C-to-T transitions was attributed to C-to-U RNA editing that developed in early stage of vascular plant evolution. On the contrary, the editing of C residues at cereal T-to-C transition sites developed mostly during cereal divergence. Most indels were associated with short direct repeats, suggesting intra- and intermolecular recombination as an important mechanism for their origin. Most of the repeats associated with indels were di- or trinucleotides, although no preference was noticed for their sequences. The maize mt genome was characterized by a high incidence of indels, comparing to the wheat and rice mt genomes.
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