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Tang J, Huang X, Sun M, Liang W. DWARF TILLER1 regulates apical-basal pattern formation and proper orientation of rice embryos. PLANT PHYSIOLOGY 2024:kiae318. [PMID: 38905146 DOI: 10.1093/plphys/kiae318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 05/10/2024] [Indexed: 06/23/2024]
Abstract
Body axis establishment is one of the earliest patterning events in plant embryogenesis. Asymmetric zygote division is critical for apical-basal axis formation in Arabidopsis (Arabidopsis thaliana). However, how the orientation of the cell division plane is regulated and its relation to apical-basal axis establishment and proper position of embryos in grasses remain poorly understood. By characterizing mutants of 3 rice (Oryza sativa) WUSCHEL HOMEOBOX9 (WOX9) genes, whose paralogs in Arabidopsis play essential roles in zygotic asymmetric cell division and cell fate determination, we found 2 kinds of independent embryonic defects: topsy-turvy embryos, in which apical-basal axis twists from being parallel to the longitudinal axis of the seed to being perpendicular; and organ-less embryos. In contrast to their Arabidopsis orthologs, OsWOX9s displayed dynamic distribution during embryo development. Both DWT1/OsWOX9A and DWL2/WOX9C play major roles in the apical-basal axis formation and initiation of stem cells. In addition, DWT1 has a distinct function in regulating the first few embryonic cell divisions to ensure the correct orientation of the embryo in the ovary. In summary, DWT1 acts in 2 steps during rice embryo pattern formation: the initial zygotic division, and with DWL2 to establish the main body axes and stem cell fate 2 to 3 d after pollination.
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Affiliation(s)
- Jingyao Tang
- Joint International Research Laboratory of Metabolic and Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaorong Huang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Mengxiang Sun
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Wanqi Liang
- Joint International Research Laboratory of Metabolic and Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Yazhou Bay Institute of Deepsea Sci-Tech, Shanghai Jiao Tong University, Sanya 572024, China
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Ishimoto K, Nosaka-Takahashi M, Kishi-Kaboshi M, Watanabe T, Abe K, Shimizu-Sato S, Takahashi H, Nakazono M, Hirochika H, Sato Y. Post-embryonic function of GLOBULAR EMBRYO 4 (GLE4)/OsMPK6 in rice development. PLANT BIOTECHNOLOGY (TOKYO, JAPAN) 2023; 40:9-13. [PMID: 38213919 PMCID: PMC10777123 DOI: 10.5511/plantbiotechnology.22.1117a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 11/17/2022] [Indexed: 01/13/2024]
Abstract
In plants, mitogen activated protein kinases (MPKs) are involved in various signaling pathways that lead to biotic and abiotic responses as well as that regulate developmental processes. Among them, MPK6 and its closely related homologue, MPK3, act redundantly and are known to be involved in asymmetric cell divisions of meristemoid mother cells in stomata development and of zygotes in Arabidopsis. Loss-of-function mutants of GLE4/OsMPK6, which is an orthologue of MPK6 in rice, showed a defect in polarity establishment in early stage of embryogenesis. However, because of the embryo lethality of the mutations, the function of GLE4/OsMPK6 in post-embryonic development is not clarified. Here, we report the analysis of post embryonic function of GLE4/OsMPK6 in vegetative stage of rice using regenerated gle4/osmpk6 homozygous plants from tissue culture. The regenerated plants are dwarf and produce multiple shoots with small leaves. These shoots never develop into reproductive stage, instead, proliferate vegetative shoots repeatedly. Leaves of gle4/osmpk6 have small leaf blade at the tip and blade-sheath boundary become obscure. Stomata arrangement is also disturbed in gle4/osmpk6 leaf blade. The shape of shoot apical meristem of gle4/osmpk6 become disorganized. Thus, GLE4/OsMPK6 functions in shoot organization and stomata patterning in the post embryonic development in rice.
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Affiliation(s)
- Kiyoe Ishimoto
- Department of Plant Production Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | | | - Mitsuko Kishi-Kaboshi
- Molecular Genetics Department, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
| | - Tsuneaki Watanabe
- Molecular Genetics Department, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
| | - Kiyomi Abe
- Molecular Genetics Department, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
| | - Sae Shimizu-Sato
- National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Hirokazu Takahashi
- Department of Plant Production Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Mikio Nakazono
- Department of Plant Production Sciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Hirohiko Hirochika
- Molecular Genetics Department, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
| | - Yutaka Sato
- National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
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Nagata H, Ono A, Tonosaki K, Kawakatsu T, Sato Y, Yano K, Kishima Y, Kinoshita T. Temporal changes in transcripts of miniature inverted-repeat transposable elements during rice endosperm development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:1035-1047. [PMID: 35128739 PMCID: PMC9314911 DOI: 10.1111/tpj.15698] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 01/19/2022] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
The repression of transcription from transposable elements (TEs) by DNA methylation is necessary to maintain genome integrity and prevent harmful mutations. However, under certain circumstances, TEs may escape from the host defense system and reactivate their transcription. In Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa), DNA demethylases target the sequences derived from TEs in the central cell, the progenitor cell for the endosperm in the female gametophyte. Genome-wide DNA demethylation is also observed in the endosperm after fertilization. In the present study, we used a custom microarray to survey the transcripts generated from TEs during rice endosperm development and at selected time points in the embryo as a control. The expression patterns of TE transcripts are dynamically up- and downregulated during endosperm development, especially those of miniature inverted-repeat TEs (MITEs). Some TE transcripts were directionally controlled, whereas the other DNA transposons and retrotransposons were not. We also discovered the NUCLEAR FACTOR Y binding motif, CCAAT, in the region near the 5' terminal inverted repeat of Youren, one of the transcribed MITEs in the endosperm. Our results uncover dynamic changes in TE activity during endosperm development in rice.
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Affiliation(s)
- Hiroki Nagata
- Kihara Institute for Biological Research, Yokohama City University641‐12 MaiokaTotsuka, YokohamaKanagawa244‐0813Japan
| | - Akemi Ono
- Kihara Institute for Biological Research, Yokohama City University641‐12 MaiokaTotsuka, YokohamaKanagawa244‐0813Japan
| | - Kaoru Tonosaki
- Kihara Institute for Biological Research, Yokohama City University641‐12 MaiokaTotsuka, YokohamaKanagawa244‐0813Japan
- Faculty of AgricultureIwate University3‐18‐8 UedaMoriokaIwate020‐8550Japan
| | - Taiji Kawakatsu
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization3‐1‐3 Kan‐nondaiTsukubaIbaraki305‐8604Japan
| | - Yutaka Sato
- Genetic Strains Research CenterNational Institute of GeneticsMishima, Shizuoka411‐8540Japan
| | - Kentaro Yano
- Department of Life SciencesSchool of Agriculture, Meiji University1‐1‐1 Higashi‐mitaKawasaki214‐8571Japan
| | - Yuji Kishima
- Research Faculty of AgricultureHokkaido UniversityKita‐9 Nishi‐9Kita‐ku, Sapporo060‐8589Japan
| | - Tetsu Kinoshita
- Kihara Institute for Biological Research, Yokohama City University641‐12 MaiokaTotsuka, YokohamaKanagawa244‐0813Japan
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Wang P, Li J, Zhang Z, Zhang Q, Li X, Xiao J, Ma H, Wang S. OsVQ1 links rice immunity and flowering via interaction with a mitogen-activated protein kinase OsMPK6. PLANT CELL REPORTS 2021; 40:1989-1999. [PMID: 34368900 DOI: 10.1007/s00299-021-02766-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
Knocking out OsVQ1 in rice released OsMPK6 for activation and in turn promoted H2O2 accumulation, which repressed the expression of flowering-promoting genes, thus delaying rice flowering but enhancing disease resistance. The valine-glutamine (VQ) protein family, which contains the conserved motif FxxxVQxLTG ("x" represents any amino acid), plays a crucial role in plant growth and immunity along with mitogen-activated protein kinase (MAPK) cascades. However, only a few rice VQ proteins have been functionally characterized, and the roles of the MAPK-VQ module in rice biological processes are not fully understood. Here, we investigated the role of OsVQ1 in rice disease resistance and the control of flowering time. The OsVQ1-knock out (KO) mutants exhibited increased resistance to Xanthomonas oryzae pathovars, accumulated high levels of hydrogen peroxide (H2O2), and showed a late flowering phenotype under natural long-day conditions, while the OsVQ1-overexpressing plants showed phenotypes similar to that of the wild type. Further studies revealed that OsVQ1 physically interacted with and inhibited OsMPK6 activity. In addition, OsVQ1 expression was downregulated by the pathogen-induced OsMPKK10.2-OsMPK6-OsWRKY45 cascade, suggesting a feedback loop between OsVQ1 and OsMPK6. Moreover, the OsVQ1-KO/osmpk6 double-mutant exhibited increased susceptibility to X. oryzae infection and showed an early flowering phenotype, which may partially be attributed to the reduced accumulation of H2O2 and the consequent up-expression of flowering-promoting genes. These results suggested that the OsVQ1-OsMPK6 module was involved in rice immunity and flowering.
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Affiliation(s)
- Peilun Wang
- National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Juan Li
- National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhenzhen Zhang
- National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Qinglu Zhang
- National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Xianghua Li
- National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Jinghua Xiao
- National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
| | - Haigang Ma
- National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China.
| | - Shiping Wang
- National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China.
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Takafuji Y, Shimizu-Sato S, Ta KN, Suzuki T, Nosaka-Takahashi M, Oiwa T, Kimura W, Katoh H, Fukai M, Takeda S, Sato Y, Hattori T. High-resolution spatiotemporal transcriptome analyses during cellularization of rice endosperm unveil the earliest gene regulation critical for aleurone and starchy endosperm cell fate specification. JOURNAL OF PLANT RESEARCH 2021; 134:1061-1081. [PMID: 34279738 DOI: 10.1007/s10265-021-01329-w] [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: 06/04/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
The major tissues of the cereal endosperm are the starchy endosperm (SE) in the inner and the aleurone layer (AL) at the outer periphery. The fates of the cells that comprise these tissues are determined according to positional information; however, our understanding of the underlying molecular mechanisms remains limited. Here, we conducted a high-resolution spatiotemporal analysis of the rice endosperm transcriptome during early cellularization. In rice, endosperm cellularization proceeds in a concentric pattern from a primary alveolus cell layer, such that developmental progression can be defined by the number of cell layers. Using laser-capture microdissection to obtain precise tissue sections, transcriptomic changes were followed through five histologically defined stages of cellularization from the syncytial to 3-cell layer (3 L) stage. In addition, transcriptomes were compared between the inner and the outermost peripheral cell layers. Large differences in the transcriptomes between stages and between the inner and the peripheral cells were found. SE attributes were expressed at the alveolus-cell-layer stage but were preferentially activated in the inner cell layers that resulted from periclinal division of the alveolus cell layer. Similarly, AL attributes started to be expressed only after the 2 L stage and were localized to the outermost peripheral cell layer. These results indicate that the first periclinal division of the alveolus cell layer is asymmetric at the transcriptome level, and that the cell-fate-specifying positional cues and their perception system are already operating before the first periclinal division. Several genes related to epidermal identity (i.e., type IV homeodomain-leucine zipper genes and wax biosynthetic genes) were also found to be expressed at the syncytial stage, but their expression was localized to the outermost peripheral cell layer from the 2 L stage onward. We believe that our findings significantly enhance our knowledge of the mechanisms underlying cell fate specification in rice endosperm.
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Affiliation(s)
- Yoshinori Takafuji
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | - Sae Shimizu-Sato
- National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Kim Nhung Ta
- National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Toshiya Suzuki
- National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
- Department of Genetics, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Misuzu Nosaka-Takahashi
- National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
- Department of Genetics, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Tetsuro Oiwa
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | - Wakana Kimura
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | - Hirokazu Katoh
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | - Mao Fukai
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | - Shin Takeda
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan.
| | - Yutaka Sato
- National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
- Department of Genetics, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
| | - Tsukaho Hattori
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan.
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Dresselhaus T, Jürgens G. Comparative Embryogenesis in Angiosperms: Activation and Patterning of Embryonic Cell Lineages. ANNUAL REVIEW OF PLANT BIOLOGY 2021; 72:641-676. [PMID: 33606951 DOI: 10.1146/annurev-arplant-082520-094112] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Following fertilization in flowering plants (angiosperms), egg and sperm cells unite to form the zygote, which generates an entire new organism through a process called embryogenesis. In this review, we provide a comparative perspective on early zygotic embryogenesis in flowering plants by using the Poaceae maize and rice as monocot grass and crop models as well as Arabidopsis as a eudicot model of the Brassicaceae family. Beginning with the activation of the egg cell, we summarize and discuss the process of maternal-to-zygotic transition in plants, also taking recent work on parthenogenesis and haploid induction into consideration. Aspects like imprinting, which is mainly associated with endosperm development and somatic embryogenesis, are not considered. Controversial findings about the timing of zygotic genome activation as well as maternal versus paternal contribution to zygote and early embryo development are highlighted. The establishment of zygotic polarity, asymmetric division, and apical and basal cell lineages represents another chapter in which we also examine and compare the role of major signaling pathways, cell fate genes, and hormones in early embryogenesis. Except for the model Arabidopsis, little is known about embryopatterning and the establishment of the basic body plan in angiosperms. Using available in situ hybridization, RNA-sequencing, and marker data, we try to compare how and when stem cell niches are established. Finally, evolutionary aspects of plant embryo development are discussed.
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Affiliation(s)
- Thomas Dresselhaus
- Department of Cell Biology and Plant Biochemistry, University of Regensburg, D-93053 Regensburg, Germany;
| | - Gerd Jürgens
- Department of Cell Biology, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
- Center for Plant Molecular Biology, University of Tübingen, D-72076 Tübingen, Germany;
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Qi D, Wen Q, Meng Z, Yuan S, Guo H, Zhao H, Cui S. OsLFR is essential for early endosperm and embryo development by interacting with SWI/SNF complex members in Oryza sativa. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:901-916. [PMID: 32808364 DOI: 10.1111/tpj.14967] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 07/09/2020] [Accepted: 07/29/2020] [Indexed: 05/26/2023]
Abstract
Rice (Oryza sativa L.) endosperm provides the developing embryo with nutrients and provides human beings with a staple food. The embryo eventually develops into a new sporophyte generation. Despite their important roles, the molecular mechanisms underlying early-stage endosperm and embryo development remain elusive. Here, we established the fundamental functions of rice OsLFR, an ortholog of the Arabidopsis SWI/SNF chromatin-remodeling complex (CRC) component LFR. OsLFR was expressed primarily in the rice spikelets and seeds, and the OsLFR protein was localized to the nucleus. We conducted genetic, cellular and molecular analyses of loss-of-function mutants and transgenic rescue lines. OsLFR depletion resulted in homozygous lethality in the early seed stage through endosperm and embryo defects, which could be successfully recovered by the OsLFR genomic sequence. Cytological observations revealed that the oslfr endosperm had relatively fewer free nuclei, had abnormal and arrested cellularization, and demonstrated premature programed cell death: the embryo was reduced in size and failed to differentiate. Transcriptome profiling showed that many genes, involved in DNA replication, cell cycle, cell wall assembly and cell death, were differentially expressed in a knockout mutant of OsLFR (oslfr-1), which was consistent with the observed seed defects. Protein-protein interaction analysis showed that OsLFR physically interacts with several putative rice SWI/SNF CRC components. Our findings demonstrate that OsLFR, possibly as one component of the SWI/SNF CRC, is an essential regulator of rice seed development, and provide further insights into the regulatory mechanism of early-stage rice endosperm and embryo development.
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Affiliation(s)
- Dongmei Qi
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
| | - Qingqing Wen
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
| | - Ze Meng
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
| | - Shan Yuan
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
| | - Hong Guo
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
| | - Hongtao Zhao
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
| | - Sujuan Cui
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Normal University, Hebei, 050024, China
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Normal University, Hebei, 050024, China
- Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Hebei, 050024, China
- College of Life Science, Hebei Normal University, Hebei, 050024, China
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8
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Kimata Y, Ueda M. Intracellular dynamics and transcriptional regulations in plant zygotes: a case study of Arabidopsis. PLANT REPRODUCTION 2020; 33:89-96. [PMID: 32322957 DOI: 10.1007/s00497-020-00389-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/09/2020] [Indexed: 06/11/2023]
Abstract
Recent understandings ofArabidopsiszygote. Body axis formation is essential for the proper development of multicellular organisms. The apical-basal axis in Arabidopsis thaliana is determined by the asymmetric division of the zygote, following its cellular polarization. However, the regulatory mechanism of zygote polarization is unclear due to technical issues. The zygote is located deep in the seed (ovule) in flowers, which prevents the living dynamics of zygotes from being observed. In addition, elucidation of molecular pathways by conventional forward genetic screens was not enough because of high gene redundancy in early development. Here, we present a review introducing two new methods, which have been developed to overcome these problems. Method 1: the two-photon live-cell imaging method provides a new system to visualize the dynamics of intracellular structures in Arabidopsis zygotes, such as cytoskeletons and vacuoles. Microtubules form transverse rings and control zygote elongation, while vacuoles dynamically change their shapes along longitudinal actin filaments and support polar nuclear migration. Method 2: the transcriptome method uses isolated Arabidopsis zygotes and egg cells to reveal the gene expression profiles before and after fertilization. This approach revealed that de novo transcription occurs extensively and immediately after fertilization. Moreover, inhibition of the de novo transcription was shown to sufficiently block the zygotic division, thus indicating a strong possibility that yet unidentified zygote regulators can be found using this transcriptome approach. These new strategies in Arabidopsis will help to further our understanding of the fundamental principles regarding the proper formation of plant bodies from unicellular zygotes.
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Affiliation(s)
- Yusuke Kimata
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
| | - Minako Ueda
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan.
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan.
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9
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Jacob D, Brian J. The short and intricate life of the suspensor. PHYSIOLOGIA PLANTARUM 2020; 169:110-121. [PMID: 31808953 DOI: 10.1111/ppl.13057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/04/2019] [Accepted: 12/04/2019] [Indexed: 06/10/2023]
Abstract
The suspensor is a short-lived tissue critical for proper embryonic development in many higher plants. While the tissue was initially thought to simply suspend the embryo in the endosperm, it has been found through decades of research that it serves multiple important purposes. The suspensor has been found to be vital for proper embryo patterning and numerous studies have been undertaken into the complex transcriptional cross-talk between the suspensor and the embryo proper. Indeed, many suspensor mutants also display abnormalities in the embryo. The suspensor's role as a nutrient conduit has been shown using ultrastructural and histochemical techniques. Biochemical approaches have found that the suspensor is a centre of early embryonic hormone production in several species. The suspensor has also been frequently used as a model for programmed cell death as it shows signs of termination almost immediately upon developing. This review covers the essential functions of the suspensor throughout its short existence from multiple disciplines including structural, genetic and biochemical perspectives.
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Affiliation(s)
- Downs Jacob
- Faculty of Science, University of Sydney, Sydney, NSW, 2006, Australia
| | - Jones Brian
- Faculty of Science, University of Sydney, Sydney, NSW, 2006, Australia
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