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Current Opinion in Plant Biology Feb 2013Expression profiling of single cells can yield insights into cell specification, cellular differentiation processes, and cell type-specific responses to environmental... (Review)
Review
Expression profiling of single cells can yield insights into cell specification, cellular differentiation processes, and cell type-specific responses to environmental stimuli. Recent work has established excellent tools to perform genome-wide expression studies of individual cell types, even if the cells of interest occur at low frequency within an organ. We review the advances and impact of gene expression studies of rare cell types, as exemplified by recently gained insights into the development and function of the angiosperm female gametophyte. The detailed transcriptional characterization of different stages during female gametophyte development has significantly helped to improve our understanding of cellular specification or cell-cell communication processes. Next-generation sequencing approaches--used increasingly for expression profiling--will now allow for comparative approaches that focus on agriculturally, ecologically or evolutionarily relevant aspects of plant reproduction.
Topics: Cell Differentiation; Gene Expression Profiling; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; High-Throughput Nucleotide Sequencing; Magnoliopsida; Organ Specificity; Ovule; Reproduction; Sequence Analysis, DNA; Single-Cell Analysis
PubMed: 23276786
DOI: 10.1016/j.pbi.2012.12.001 -
International Journal of Molecular... Jan 2023The European grapevine ( L.) is one of the world's most widely cultivated and economically important fruit crops. Seedless fruits are particularly desired for table...
The European grapevine ( L.) is one of the world's most widely cultivated and economically important fruit crops. Seedless fruits are particularly desired for table grapes, with seedlessness resulting from stenospermocarpy being an important goal for cultivar improvement. The establishment of an RNA in situ hybridisation (ISH) system for grape berries and ovules is, therefore, important for understanding the molecular mechanisms of ovule abortion in stenospermocarpic seedless cultivars. We improved RNA in situ hybridisation procedures for developing berries and ovules by targeting two transcription factor genes, and , using two seeded varieties, 'Red Globe' and 'Pinot Noir', and two seedless cultivars, 'Flame Seedless' and 'Thompson Seedless'. Optimisation focused on the time of proteinase K treatment, probe length, probe concentration, hybridisation temperature and post-hybridisation washing conditions. The objectives were to maximise hybridisation signals and minimise background interference, while still preserving tissue integrity. For the target genes and samples tested, the best results were obtained with a pre-hybridisation proteinase K treatment of 30 min, probe length of 150 bp and concentration of 100 ng/mL, hybridisation temperature of 50 °C, three washes with 0.2× saline sodium citrate (SSC) solution and blocking with 1% blocking reagent for 45 min during the subsequent hybridisation. The improved ISH system was used to study the spatiotemporal expression patterns of genes related to ovule development at a microscopic level.
Topics: Fruit; Ovule; RNA; Endopeptidase K; Seeds; Vitis
PubMed: 36614240
DOI: 10.3390/ijms24010800 -
ELife Jan 2021A fundamental question in biology is how morphogenesis integrates the multitude of processes that act at different scales, ranging from the molecular control of gene...
A fundamental question in biology is how morphogenesis integrates the multitude of processes that act at different scales, ranging from the molecular control of gene expression to cellular coordination in a tissue. Using machine-learning-based digital image analysis, we generated a three-dimensional atlas of ovule development in , enabling the quantitative spatio-temporal analysis of cellular and gene expression patterns with cell and tissue resolution. We discovered novel morphological manifestations of ovule polarity, a new mode of cell layer formation, and previously unrecognized subepidermal cell populations that initiate ovule curvature. The data suggest an irregular cellular build-up of expression in the primordium and new functions for in restricting nucellar cell proliferation and the organization of the interior chalaza. Our work demonstrates the analytical power of a three-dimensional digital representation when studying the morphogenesis of an organ of complex architecture that eventually consists of 1900 cells.
Topics: Arabidopsis; Cell Proliferation; Flowers; Gene Expression Regulation, Developmental; Ovule
PubMed: 33404501
DOI: 10.7554/eLife.63262 -
Plant Physiology May 2017Tetrapyrrole biosynthesis is one of the most essential metabolic pathways in almost all organisms. Coproporphyrinogen III oxidase (CPO) catalyzes the conversion of...
Tetrapyrrole biosynthesis is one of the most essential metabolic pathways in almost all organisms. Coproporphyrinogen III oxidase (CPO) catalyzes the conversion of coproporphyrinogen III into protoporphyrinogen IX in this pathway. Here, we report that mutation in the Arabidopsis () CPO-coding gene () adversely affects silique length, ovule number, and seed set. mutant alleles were transmitted via both male and female gametes, but homozygous mutants were never recovered. Plants carrying mutant alleles showed defects in gametophyte development, including nonviable pollen and embryo sacs with unfused polar nuclei. Improper differentiation of the central cell led to defects in endosperm development. Consequently, embryo development was arrested at the globular stage. The mutant phenotype was completely rescued by transgenic expression of Promoter and transcript analyses indicated that is expressed mainly in floral tissues and developing seeds. AtHEMN1-green fluorescent protein fusion protein was found targeted to mitochondria. Loss of function increased coproporphyrinogen III level and reduced protoporphyrinogen IX level, suggesting the impairment of tetrapyrrole biosynthesis. Blockage of tetrapyrrole biosynthesis in the mutant led to increased reactive oxygen species (ROS) accumulation in anthers and embryo sacs, as evidenced by nitroblue tetrazolium staining. Our results suggest that the accumulated ROS disrupts mitochondrial function by altering their membrane polarity in floral tissues. This study highlights the role of mitochondrial ROS homeostasis in gametophyte and seed development and sheds new light on tetrapyrrole/heme biosynthesis in plant mitochondria.
Topics: Arabidopsis; Arabidopsis Proteins; Coproporphyrinogen Oxidase; Coproporphyrinogens; Endosperm; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Germ Cells, Plant; Mitochondria; Mutation; Ovule; Plants, Genetically Modified; Pollen; Reactive Oxygen Species; Seeds
PubMed: 28270625
DOI: 10.1104/pp.16.01482 -
Proceedings of the National Academy of... Oct 2011The present study investigated whether kisspeptin-G protein-coupled receptor 54 (GPR54) signaling plays a role in mediating mating-induced ovulation in the musk shrew...
The present study investigated whether kisspeptin-G protein-coupled receptor 54 (GPR54) signaling plays a role in mediating mating-induced ovulation in the musk shrew (Suncus murinus), a reflex ovulator. For this purpose, we cloned suncus Kiss1 and Gpr54 cDNA from the hypothalamus and found that suncus kisspeptin (sKp) consists of 29 amino acid residues (sKp-29). Injection of exogenous sKp-29 mimicked the mating stimulus to induce follicular maturation and ovulation. Administration of several kisspeptins and GPR54 agonists also induced presumed ovulation in a dose-dependent manner, and Gpr54 mRNA was distributed in the hypothalamus, showing that kisspeptins induce ovulation through binding to GPR54. The sKp-29-induced ovulation was blocked completely by pretreatment with a gonadotropin-releasing hormone (GnRH) antagonist, suggesting that kisspeptin activates GnRH neurons to induce ovulation in the musk shrew. In addition, in situ hybridization revealed that Kiss1-expressing cells are located in the medial preoptic area (POA) and arcuate nucleus in the musk shrew hypothalamus. The number of Kiss1-expressing cells in the POA or arcuate nucleus was up-regulated or down-regulated by estradiol, suggesting that kisspeptin neurons in these regions were the targets of the estrogen feedback action. Finally, mating stimulus largely induced c-Fos expression in Kiss1-positive cells in the POA, indicating that the mating stimulus activates POA kisspeptin neurons to induce ovulation. Taken together, these results indicate that kisspeptin-GPR54 signaling plays a role in the induction of ovulation in the musk shrew, a reflex ovulator, as it does in spontaneous ovulators.
Topics: Amino Acid Sequence; Animals; Arcuate Nucleus of Hypothalamus; Base Sequence; Copulation; Corpus Luteum; DNA, Complementary; Estradiol; Female; Gene Expression; Gonadotropin-Releasing Hormone; Kisspeptins; Male; Molecular Sequence Data; Ovarian Follicle; Ovulation; Phylogeny; Preoptic Area; RNA, Messenger; Receptors, G-Protein-Coupled; Sequence Homology, Amino Acid; Shrews; Tissue Distribution
PubMed: 21987818
DOI: 10.1073/pnas.1113035108 -
Annals of Botany Sep 2018In the Brassicaceae family, apomictic development is characteristic of the genus Boechera. Hybridization, polyploidy and environmental adaptation that arose during the...
BACKGROUND AND AIMS
In the Brassicaceae family, apomictic development is characteristic of the genus Boechera. Hybridization, polyploidy and environmental adaptation that arose during the evolution of Boechera may serve as (epi)genetic regulators of apomictic initiation in this genus. Here we focus on Boechera stricta, a predominantly diploid species that reproduces sexually. However, apomictic development in this species has been reported in several studies, indicating non-obligate sexuality.
METHODS
A progressive investigation of flower development was conducted using three accessions to assess the reproductive system of B. stricta. We employed molecular and cyto-embryological identification using histochemistry, transmission electron microscopy and Nomarski and epifluorescence microscopy.
KEY RESULTS
Data from internal transcribed spacer (ITS) and chloroplast haplotype sequencing, in addition to microsatellite variation, confirmed the B. stricta genotype for all lines. Embryological data indicated irregularities in sexual reproduction manifested by heterochronic ovule development, longevity of meiocyte and dyad stages, diverse callose accumulation during meiocyte-to-gametophyte development, and the formation of triads and tetrads in several patterns. The arabinogalactan-related sugar epitope recognized by JIM13 immunolocalized to one or more megaspores. Furthermore, pollen sterility and a high frequency of seed abortion appeared to accompany reproduction of the accession ES512, along with the initiation of parthenogenesis. Data from flow cytometric screening revealed both sexual and apomictic seed formation.
CONCLUSION
These results imply that B. stricta is a species with an underlying ability to initiate apomixis, at least with respect to the lines examined here. The existence of apomixis in an otherwise diploid sexual B. stricta may provide the genomic building blocks for establishing highly penetrant apomictic diploids and hybrid relatives. Our findings demonstrate that apomixis per se is a variable trait upon which natural selection could act.
Topics: Apomixis; Brassicaceae; Diploidy; Genome, Plant; Genotype; Hybridization, Genetic; Microsatellite Repeats; Ovule; Phenotype; Pollen; Polyploidy; Seeds; Selection, Genetic
PubMed: 29982367
DOI: 10.1093/aob/mcy114 -
International Journal of Molecular... Mar 2024Strigolactones (SLs) were recently defined as a novel class of plant hormones that act as key regulators of diverse developmental processes and environmental responses....
Strigolactones (SLs) were recently defined as a novel class of plant hormones that act as key regulators of diverse developmental processes and environmental responses. Much research has focused on SL biosynthesis and signaling in roots and shoots, but little is known about whether SLs are produced in early developing seeds and about their roles in ovule development after fertilization. This study revealed that the fertilized ovules and early developing pericarp in produced minute amounts of two strigolactones: 5-deoxystrigol and strigol. Their content decreased in the plants with the addition of exogenous phosphate (Pi) compared to those without the Pi treatment. The exogenous application of an SL analog (GR24) and a specific inhibitor of SL biosynthesis (TIS108) affected early seed development and fruit set. In the genome, we identified 69 potential homologs of genes involved in SL biological synthesis and signaling. Using RNA-seq to characterize the expression of these genes in the fertilized ovules, 37 genes were found to express differently in the fertilized ovules that were aborting compared to the normally developing ovules. A transcriptome analysis also revealed that in normally developing ovules after fertilization, 12 potential invertase genes were actively expressed. Hexoses (glucose and fructose) accumulated at high concentrations in normally developing ovules during syncytial endosperm development. In contrast, a low ratio of hexose and sucrose levels was detected in aborting ovules with a high strigolactone content. virus-induced gene silencing (VIGS) increased the hexose content in fertilized ovules and induced the proliferation of endosperm free nuclei, thereby promoting early seed development and fruit set. We propose that the crosstalk between sugar and strigolactone signals may be an important part of a system that accurately regulates the abortion of ovules after fertilization. This study is useful for understanding the mechanisms underlying ovule abortion, which will serve as a guide for genetic or chemical approaches to promote seed yield in .
Topics: Ovule; Fertilization; Seeds; Sapindaceae; Hexoses; Gene Expression Regulation, Plant; Heterocyclic Compounds, 3-Ring; Lactones
PubMed: 38542248
DOI: 10.3390/ijms25063276 -
Nature Communications Sep 2018The date palm tree is a commercially important member of the genus Phoenix whose 14 species are dioecious with separate male and female individuals. To identify sex...
The date palm tree is a commercially important member of the genus Phoenix whose 14 species are dioecious with separate male and female individuals. To identify sex determining genes we sequenced the genomes of 15 female and 13 male Phoenix trees representing all 14 species. We identified male-specific sequences and extended them using phased single-molecule sequencing or BAC clones. We observed that only four genes contained sequences conserved in all analyzed Phoenix males. Most of these sequences showed similarity to a single genomic locus in the closely related monoecious oil palm. CYP703 and GPAT3, two single copy genes present in males and critical for male flower development in other monocots, were absent in females. A LOG-like gene appears translocated into the Y-linked region and is suggested to play a role in suppressing female flowers. Our data are consistent with a two-mutation model for the evolution of dioecy in Phoenix.
Topics: Genes, Plant; Genome, Plant; High-Throughput Nucleotide Sequencing; Models, Genetic; Mutation; Ovule; Phoeniceae; Pollen; Species Specificity
PubMed: 30266991
DOI: 10.1038/s41467-018-06375-y -
The Plant Cell Sep 2020
Topics: Arabidopsis; Female; Gene Expression Regulation, Plant; Germ Cells; Ovule; RNA Interference; RNA, Plant
PubMed: 32753429
DOI: 10.1105/tpc.20.00599 -
American Journal of Botany Dec 2021Unlike most flowering plants, orchid flowers have under-developed ovules that complete development only after pollination. Classical studies reported variation in the...
PREMISE
Unlike most flowering plants, orchid flowers have under-developed ovules that complete development only after pollination. Classical studies reported variation in the stage in which ovule development is arrested, but the extent of this variation and its evolutionary and ecological significance are unclear.
METHODS
Here, we used light microscopy to observe ovule development at anthesis for 39 species not previously studied and surveyed the literature gaining information on 94 orchid species. Tropical and temperate members of all five orchid subfamilies as well as species with contrasting pollination strategies (rewarding versus deceptive) and life forms (epiphytic versus terrestrial) were represented. We analyzed the data using statistical comparisons and a phylogenetic generalized least square (PGLS) analysis.
RESULTS
Apostasioideae, the sister to the rest of the orchids, have mature ovules similar to other Asparagales, while under-differentiated ovules are present in the other subfamilies. Ovule developmental stages showed high variation even among closely related groups. Ovules were more developed in terrestrial than in epiphytic, in temperate than in tropical, and in rewarding than in deceptive pollination orchid species. This latter comparison was also significant in the PGLS analysis.
CONCLUSIONS
These results suggest that ovule developmental stage in orchids can be shaped by ecological factors, such as seasonality and pollination strategy, and can be selected for optimizing female reproductive investment.
Topics: Flowers; Orchidaceae; Ovule; Phylogeny; Pollination
PubMed: 34622937
DOI: 10.1002/ajb2.1770