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Cheng X, Pan M, E Z, Zhou Y, Niu B, Chen C. The maternally expressed polycomb group gene OsEMF2a is essential for endosperm cellularization and imprinting in rice. PLANT COMMUNICATIONS 2021; 2:100092. [PMID: 33511344 PMCID: PMC7816080 DOI: 10.1016/j.xplc.2020.100092] [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] [Received: 02/02/2020] [Revised: 06/17/2020] [Accepted: 06/22/2020] [Indexed: 05/18/2023]
Abstract
Cellularization is a key event in endosperm development. Polycomb group (PcG) genes, such as Fertilization-Independent Seed 2 (FIS2), are vital for the syncytium-to-cellularization transition in Arabidopsis plants. In this study, we found that OsEMF2a, a rice homolog of the Arabidopsis PcG gene Embryonic Flower2 (EMF2), plays a role similar to that of FIS2 in regard to seed development, although there is limited sequence similarity between the genes. Delayed cellularization was observed in osemf2a, associated with an unusual activation of type I MADS-box genes. The cell cycle was persistently activated in osemf2a caryopses, which was likely caused by cytokinin overproduction. However, the overaccumulation of auxin was not found to be associated with the delayed cellularization. As OsEMF2a is a maternally expressed gene in the endosperm, a paternally inherited functional allele was unable to recover the maternal defects of OsEMF2a. Many imprinted rice genes were deregulated in the defective hybrid seeds of osemf2a (♀)/9311 (♂) (m9). The paternal expression bias of some paternally expressed genes was disrupted in m9 due to either the activation of maternal alleles or the repression of paternal alleles. These findings suggest that OsEMF2a-PRC2-mediated H3K27me3 is necessary for endosperm cellularization and genomic imprinting in rice.
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Affiliation(s)
- Xiaojun Cheng
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| | - Meiyao Pan
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| | - Zhiguo E
- Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Yong Zhou
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| | - Baixiao Niu
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
| | - Chen Chen
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, China
- Corresponding author
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Dhatt BK, Paul P, Sandhu J, Hussain W, Irvin L, Zhu F, Adviento‐Borbe MA, Lorence A, Staswick P, Yu H, Morota G, Walia H. Allelic variation in rice Fertilization Independent Endosperm 1 contributes to grain width under high night temperature stress. THE NEW PHYTOLOGIST 2021; 229:335-350. [PMID: 32858766 PMCID: PMC7756756 DOI: 10.1111/nph.16897] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 08/09/2020] [Indexed: 05/23/2023]
Abstract
A higher minimum (night-time) temperature is considered a greater limiting factor for reduced rice yield than a similar increase in maximum (daytime) temperature. While the physiological impact of high night temperature (HNT) has been studied, the genetic and molecular basis of HNT stress response remains unexplored. We examined the phenotypic variation for mature grain size (length and width) in a diverse set of rice accessions under HNT stress. Genome-wide association analysis identified several HNT-specific loci regulating grain size as well as loci that are common for optimal and HNT stress conditions. A novel locus contributing to grain width under HNT conditions colocalized with Fie1, a component of the FIS-PRC2 complex. Our results suggest that the allelic difference controlling grain width under HNT is a result of differential transcript-level response of Fie1 in grains developing under HNT stress. We present evidence to support the role of Fie1 in grain size regulation by testing overexpression (OE) and knockout mutants under heat stress. The OE mutants were either unaltered or had a positive impact on mature grain size under HNT, while the knockouts exhibited significant grain size reduction under these conditions.
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Affiliation(s)
- Balpreet K. Dhatt
- Department of Agronomy and HorticultureUniversity of Nebraska‐LincolnLincolnNE68583USA
| | - Puneet Paul
- Department of Agronomy and HorticultureUniversity of Nebraska‐LincolnLincolnNE68583USA
| | - Jaspreet Sandhu
- Department of Agronomy and HorticultureUniversity of Nebraska‐LincolnLincolnNE68583USA
| | - Waseem Hussain
- Department of Agronomy and HorticultureUniversity of Nebraska‐LincolnLincolnNE68583USA
| | - Larissa Irvin
- Department of Agronomy and HorticultureUniversity of Nebraska‐LincolnLincolnNE68583USA
| | - Feiyu Zhu
- Department of Computer Science and EngineeringUniversity of Nebraska‐LincolnLincolnNE68588USA
| | | | - Argelia Lorence
- Department of Chemistry and PhysicsArkansas Biosciences InstituteArkansas State UniversityJonesboroAR72467USA
| | - Paul Staswick
- Department of Agronomy and HorticultureUniversity of Nebraska‐LincolnLincolnNE68583USA
| | - Hongfeng Yu
- Department of Computer Science and EngineeringUniversity of Nebraska‐LincolnLincolnNE68588USA
| | - Gota Morota
- Department of Animal and Poultry SciencesVirginia Polytechnic Institute and State UniversityBlacksburgVA24061USA
| | - Harkamal Walia
- Department of Agronomy and HorticultureUniversity of Nebraska‐LincolnLincolnNE68583USA
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Niu B, Deng H, Li T, Sharma S, Yun Q, Li Q, E Z, Chen C. OsbZIP76 interacts with OsNF-YBs and regulates endosperm cellularization in rice (Oryza sativa). JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2020; 62:1983-1996. [PMID: 32621654 DOI: 10.1111/jipb.12989] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/03/2020] [Indexed: 05/23/2023]
Abstract
Following double fertilization, plant endosperm nuclei undergo syncytial divisions, followed by synchronous cellularization. Cellularization is a key event during endosperm development, but our understanding of its regulation is limited to Arabidopsis. In this study we show that OsbZIP76 regulates cellularization in rice (Oryza sativa). Activation of OsbZIP76 coincided with the initiation of cellularization, and its knockdown or knockout mutants exhibited precocious cellularization. Genes involved in endosperm development or starch biosynthesis were prematurely activated in the osbzip76 caryopsis. As a putative transcription factor, OsbZIP76 alone lacked transcriptional activation activity; however, it interacted with the nuclear factor Y (NF-Y) family transcription factors OsNF-YB9 and OsNF-YB1 in yeast and in planta. OsbZIP76 and OsNF-YB9 were predominantly expressed in the endosperm and the proteins colocalized. Seeds of osnf-yb1 and osbzip76 mutants showed reduced size and reduced apparent amylose content. The parent-of-origin-dependent expression of OsbZIP76 is variable in different rice accessions. In summary, OsbZIP76 is an endosperm-expressed imprinted gene that regulates endosperm development in rice.
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Affiliation(s)
- Baixiao Niu
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, 225009, China
| | - Hui Deng
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, 225009, China
| | - Tingting Li
- Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310000, China
| | - Sandeep Sharma
- Department of Genetics and Plant Breeding, Institute of Agricultural Sciences, BHU, Varanasi, 221005, India
| | - Qianbin Yun
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, 225009, China
| | - Qianru Li
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, 225009, China
| | - Zhiguo E
- Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310000, China
| | - Chen Chen
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College of Yangzhou University, Yangzhou, 225009, China
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Cheng X, Pan M, E Z, Zhou Y, Niu B, Chen C. Functional divergence of two duplicated Fertilization Independent Endosperm genes in rice with respect to seed development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:124-137. [PMID: 33463824 DOI: 10.1111/tpj.14911] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 05/14/2020] [Accepted: 06/26/2020] [Indexed: 05/22/2023]
Abstract
Fertilization Independent Endosperm (FIE) is an essential member of Polycomb Repressive Complex 2 (PRC2) that plays important roles in the developmental regulation of plants. OsFIE1 and OsFIE2 are two FIE homologs in the rice genome. Here, we showed that OsFIE1 probably duplicated from OsFIE2 after the origin of the tribe Oryzeae, but has a specific expression pattern and methylation landscape. During evolution, OsFIE1 underwent a less intensive purifying selection than did OsFIE2. The mutant osfie1 produced smaller seeds and displayed reduced dormancy, indicating that OsFIE1 predominantly functions in late seed development. Ectopic expression of OsFIE1, but not OsFIE2, was deleterious to vegetative growth in a dose-dependent manner. The newly evolved N-terminal tail of OsFIE1 was probably not the cause of the adverse effects on vegetative growth. The CRISPR/Cas9-derived mutant osfie2 exhibited impaired cellularization of the endosperm, which suggested that OsFIE2 is indispensable for early seed development as a positive regulator of cellularization. Autonomous endosperm was observed in both OsFIE2+- and osfie1/OsFIE2+- but at a very low frequency. Although OsFIE1-PRC2 exhibited H3K27me3 methyltransferase ability in plants, OsFIE1-PRC2 is likely to be less important for development in rice than is OsFIE2-PRC2. Our findings revealed the functional divergence of OsFIE1 and OsFIE2 and shed light on their distinct evolution following duplication.
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Affiliation(s)
- Xiaojun Cheng
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Meiyao Pan
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Zhiguo E
- Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Yong Zhou
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Baixiao Niu
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Chen Chen
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou, China
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Controlling Apomixis: Shared Features and Distinct Characteristics of Gene Regulation. Genes (Basel) 2020; 11:genes11030329. [PMID: 32245021 PMCID: PMC7140868 DOI: 10.3390/genes11030329] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/13/2020] [Accepted: 03/18/2020] [Indexed: 02/06/2023] Open
Abstract
In higher plants, sexual and asexual reproduction through seeds (apomixis) have evolved as alternative strategies. As apomixis leads to the formation of clonal offspring, its great potential for agricultural applications has long been recognized. However, the genetic basis and the molecular control underlying apomixis and its evolutionary origin are to date not fully understood. Both in sexual and apomictic plants, reproduction is tightly controlled by versatile mechanisms regulating gene expression, translation, and protein abundance and activity. Increasing evidence suggests that interrelated pathways including epigenetic regulation, cell-cycle control, hormonal pathways, and signal transduction processes are relevant for apomixis. Additional molecular mechanisms are being identified that involve the activity of DNA- and RNA-binding proteins, such as RNA helicases which are increasingly recognized as important regulators of reproduction. Together with other factors including non-coding RNAs, their association with ribosomes is likely to be relevant for the formation and specification of the apomictic reproductive lineage. Subsequent seed formation appears to involve an interplay of transcriptional activation and repression of developmental programs by epigenetic regulatory mechanisms. In this review, insights into the genetic basis and molecular control of apomixis are presented, also taking into account potential relations to environmental stress, and considering aspects of evolution.
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Ingram GC. Family plot: the impact of the endosperm and other extra-embryonic seed tissues on angiosperm zygotic embryogenesis. F1000Res 2020; 9. [PMID: 32055398 PMCID: PMC6961419 DOI: 10.12688/f1000research.21527.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/10/2020] [Indexed: 12/22/2022] Open
Abstract
The zygotic embryos of angiosperms develop buried deep within seeds and surrounded by two main extra-embryonic tissues: the maternally derived seed coat tissues and the zygotic endosperm. Generally, these tissues are considered to play an important role in nurturing the developing embryo by acting as conduits for maternally derived nutrients. They are also critical for key seed traits (dormancy establishment and control, longevity, and physical resistance) and thus for seed and seedling survival. However, recent studies have highlighted the fact that extra-embryonic tissues in the seed also physically and metabolically limit embryonic development and that unique mechanisms may have evolved to overcome specific developmental and genetic constraints associated with the seed habit in angiosperms. The aim of this review is to illustrate how these studies have begun to reveal the highly complex physical and physiological relationship between extra-embryonic tissues and the developing embryo. Where possible I focus on Arabidopsis because of space constraints, but other systems will be cited where relevant.
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Affiliation(s)
- Gwyneth C Ingram
- Laboratoire Reproduction et Développement des Plantes, University of Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, Lyon, France
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Pires ND, Grossniklaus U. Identification of Parent-of-Origin-Dependent QTLs Using Bulk-Segregant Sequencing (Bulk-Seq). Methods Mol Biol 2018; 1675:361-371. [PMID: 29052202 DOI: 10.1007/978-1-4939-7318-7_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Parent-of-origin effects play important roles in plant reproduction and are often mediated by epigenetic modifications at the histone or DNA level. However, the genetic basis underlying these modifications can be challenging to identify. Here, we describe an approach (Bulk-Seq) that can be used to map loci mediating parent-of-origin-dependent effects using whole-genome sequencing of pools of DNA.
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Affiliation(s)
- Nuno D Pires
- Department of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zollikerstrasse 107, 8008, Zürich, Switzerland.
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology, Zürich-Basel Plant Science Center, University of Zürich, Zollikerstrasse 107, 8008, Zürich, Switzerland
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Ingram GC. Dying to live: cell elimination as a developmental strategy in angiosperm seeds. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:785-796. [PMID: 27702990 DOI: 10.1093/jxb/erw364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The complete elimination of unwanted cells during development is a repeated theme in both multicellular animals and in plants. In plants, such events have been extensively studied and reviewed in terms of their molecular regulation, of marker genes and proteins expressed, and in terms of cellular changes associated with their progression. This review will take a slightly different view of developmental cell elimination and will concentrate specifically on the numerous elimination events that occur during ovule and seed development (here grouped together as seed development). It asks why this cell elimination occurs in specific seed tissues, in order to understand something about the commonalities underlying how seemingly disparate events are triggered and regulated. Finally, by placing the seed in its broader evolutionary context, the question of why cell elimination may have emerged as such a key component of the seed developmental toolbox will be considered.
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Affiliation(s)
- Gwyneth C Ingram
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, CNRS (UMR 5667), INRA (UMR 0879), UCB Lyon 1, Ecole Normale Supérieure de Lyon, F-69342 Lyon, France
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