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Kuhn SA, Nogueira FM, Schürer T, Mariath JEA. Reproductive biology of the "Brazilian pine" (Araucaria angustifolia-Araucariaceae): the pollen tube growth and the seed cone development. PLANT REPRODUCTION 2024; 37:1-13. [PMID: 37449999 DOI: 10.1007/s00497-023-00473-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/19/2023] [Indexed: 07/18/2023]
Abstract
KEY MESSAGE In Araucaria angustifolia, the seed scale is part of the ovule, the female gametophyte presents a monosporic origin and arises from a coenocytic tetrad, and the pollen tube presents a single axis. The seed cone of conifers has many informative features, and its ontogenetic data may help interpret relationships among function, development patterns, and homology among seed plants. We reported the seed cone development, from pollination to pre-fertilization, including seed scale, ovule ontogeny, and pollen tube growth in Araucaria angustifolia. The study was performed using light microscopy, scanning electron microscopy, and X-ray microcomputed tomography (μCT). During the pollination period, the ovule arises right after the seed scale has emerged. From that event to the pre-fertilization period takes about 14 months. Megasporogenesis occurs three weeks after ovule formation, producing a coenocytic tetrad. At the same time as the female gametophyte's first nuclear division begins, the pollen tube grows through the seed scale adaxial face. Until maturity, the megagametophyte goes through the free nuclei stage, cellularization stage, and cellular growth stage. Along its development, many pollen tubes develop in the nucellar tissue extending straight toward the female gametophyte. Our observations show that the seed scale came out of the same primordia of the ovule, agreeing with past studies that this structure is part of the ovule itself. The formation of a female gametophyte with a monosporic origin that arises from a coenocytic tetrad was described for the first time in conifers, and the three-dimensional reconstruction of the ovule revealed the presence of pollen tubes with only one axis and no branches, highlighting a new pattern of pollen tube growth in Araucariaceae.
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Affiliation(s)
- Sofia A Kuhn
- Laboratório de Anatomia Vegetal (LAVeg), Instituto de Biociências, Departamento de Botânica, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Porto Alegre, RS, Brazil.
| | - Fernanda M Nogueira
- Laboratório de Biologia Molecular de Plantas, Departamento de Biologia, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto (FFCLRP) - Universidade de São Paulo-USP, Av. Bandeirantes 3900, Ribeirão Preto, 14040-901, Brazil
| | - Tainá Schürer
- Laboratório de Anatomia Vegetal (LAVeg), Instituto de Biociências, Departamento de Botânica, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Porto Alegre, RS, Brazil
| | - Jorge E A Mariath
- Laboratório de Anatomia Vegetal (LAVeg), Instituto de Biociências, Departamento de Botânica, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Porto Alegre, RS, Brazil
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Goeten D, Rogge-Renner GD, Schmidt ÉC, Bouzon ZL, Farias-Soares FL, Guerra MP, Steiner N. Updating embryonic ontogenesis in Araucaria angustifolia: from Burlingame (1915) to the present. PROTOPLASMA 2020; 257:931-948. [PMID: 31950285 DOI: 10.1007/s00709-020-01481-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 01/08/2020] [Indexed: 06/10/2023]
Abstract
This study addresses gaps in our understanding of pre-fertilization and archegonia development and reinterprets embryonic ontogenesis from Burlingame (Bot Gaz 59:1-39, 1915) to the present based on timescale and structural features allowing us to determine functionally and developmentally accurate terminology for all these stages in A. angustifolia. Different from previous reports, only after pollination, pre-fertilization tissue development occurs (0-13 months after pollination (MAP)) and gives rise to a mature megagametophyte. During all this period, pollen is in a dormant state at the microphyla, and pollen tube germination in nucellus tissue is only observed at the stage of archegonia formation (13 MAP) and not at the free nuclei stage as reported before. For the first time, 14 months after pollination, a fertilization window was indicated, and at 15 MAP, the polyzygotic polyembryony from different archegonia was also seen. After that, subordinated proembryo regression occurs and at least three embryonic developmental stages of dominant embryo were characterized: proembryogenic, early embryogenic, and late embryogenic (15-23 MAP). Along these stages, histochemical and ultrastructural analyses suggest the occurrence of cell death in suspensor and in cap cells of dominant embryo that was not previously reported. The differentiation of meristems, procambium, pith, and cortex tissues in late embryogenic stage was detailed. The morphohistological characterization of pre-fertilization and embryonic stages, together with the timescale of megastrobili development, warranted a referential map of female reproductive structure in this species.
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Affiliation(s)
- Daniela Goeten
- Plant Physiology Laboratory, Department of Botany, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, Brazil
| | - Gladys D Rogge-Renner
- Biological Sciences Department, University of Joinville Region, Joinville, SC, 89219-710, Brazil
| | - Éder C Schmidt
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, Florianópolis, SC, 88040-400, Brazil
| | - Zenilda L Bouzon
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, Florianópolis, SC, 88040-400, Brazil
| | - Francine L Farias-Soares
- Plant Developmental Physiology and Genetics Laboratory, Department of Plant Science, Federal University of Santa Catarina, Florianópolis, SC, 88034-001, Brazil
| | - Miguel P Guerra
- Plant Developmental Physiology and Genetics Laboratory, Department of Plant Science, Federal University of Santa Catarina, Florianópolis, SC, 88034-001, Brazil
- Graduate Program in Agricultural and Natural Ecosystems, Federal University of Santa Catarina, Curitibanos, SC, 89520-000, Brazil
| | - Neusa Steiner
- Plant Physiology Laboratory, Department of Botany, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, Brazil.
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Moitra A, Bhatnagar SP. Ultrastructure, cytochemical, and histochemical studies on pollen and male gamete development in gymnosperms. ACTA ACUST UNITED AC 1982. [DOI: 10.1002/mrd.1120050108] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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