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Current Opinion in Plant Biology Jun 2024Messenger RNAs (mRNAs) are the templates for protein translation but can also act as non-cell-autonomous signaling molecules. Plants input endogenous and exogenous cues... (Review)
Review
Messenger RNAs (mRNAs) are the templates for protein translation but can also act as non-cell-autonomous signaling molecules. Plants input endogenous and exogenous cues to mobile mRNAs and output them to local or systemic target cells and organs to support specific plant responses. Mobile mRNAs form ribonucleoprotein (RNP) complexes with proteins during transport. Components of these RNP complexes could interact with plasmodesmata (PDs), a major mediator of mRNA transport, to ensure mRNA mobility and transport selectivity. Based on advances in the last two to three years, this review summarizes mRNA transport mechanisms in local and systemic signaling from the perspective of RNP complex formation and PD transport. We also discuss the physiological roles of endogenous mRNA transport and the recently revealed roles of non-cell-autonomous mRNAs in inter-organism communication.
Topics: RNA, Messenger; Plasmodesmata; Ribonucleoproteins; RNA, Plant; RNA Transport; Plants; Signal Transduction; Cell Communication
PubMed: 38663258
DOI: 10.1016/j.pbi.2024.102541 -
Protoplasma Jan 2011Plasmodesmata (PD) are plasma membrane-lined cytoplasmic channels that cross the cell wall and establish symplasmic continuity between neighboring cells in plants.... (Review)
Review
Plasmodesmata (PD) are plasma membrane-lined cytoplasmic channels that cross the cell wall and establish symplasmic continuity between neighboring cells in plants. Recently, a wide range of cellular RNAs (including mRNAs and small RNAs (sRNAs)) have been reported to move from cell to cell through PD trafficking pathways. sRNAs are key molecules that function in transcriptional and post-transcriptional RNA silencing, which is a gene expression regulatory mechanism that is conserved among eukaryotes and is important for protection against invading nucleic acids (such as viruses and transposons) and for developmental and physiological regulation. One of the most intriguing aspects of RNA silencing is that it can function either cell autonomously or non-cell autonomously in post-transcriptional RNA silencing pathways. Although the mechanisms underlying cell-to-cell trafficking of RNA and RNA silencing signals are not fully understood, the movement of specific RNAs seems to play a critical role in cell-to-cell and long-distance regulation of gene expression, thereby coordinating growth and developmental processes, gene silencing, and stress responses. In this review, we summarize the current knowledge regarding cell-to-cell trafficking of RNA molecules (including small RNAs), and we discuss potential molecular mechanisms of cell-to-cell trafficking that are mediated by complex networks.
Topics: Cell Communication; MicroRNAs; Plant Proteins; Plant Vascular Bundle; Plant Viral Movement Proteins; Plasmodesmata; Potexvirus; RNA Interference; RNA Transport; RNA, Small Interfering; RNA, Viral
PubMed: 21042816
DOI: 10.1007/s00709-010-0225-6 -
Plant & Cell Physiology Nov 2021Grafting is a means to connect tissues from two individual plants and grow a single chimeric plant through the establishment of both apoplasmic and symplasmic... (Review)
Review
Grafting is a means to connect tissues from two individual plants and grow a single chimeric plant through the establishment of both apoplasmic and symplasmic connections. Recent molecular studies using RNA-sequencing data have provided genetic information on the processes involved in tissue reunion, including wound response, cell division, cell-cell adhesion, cell differentiation and vascular formation. Thus, studies on grafting increase our understanding of various aspects of plant biology. Grafting has also been used to study systemic signaling and transport of micromolecules and macromolecules in the plant body. Given that graft viability and molecular transport across graft junctions largely depend on vascular formation, a major focus in grafting biology has been the mechanism of vascular development. In addition, it has been thought that symplasmic connections via plasmodesmata are fundamentally important to share cellular information among newly proliferated cells at the graft interface and to accomplish tissue differentiation correctly. Therefore, this review focuses on plasmodesmata formation during grafting. We take advantage of interfamily grafts for unambiguous identification of the graft interface and summarize morphological aspects of de novo formation of plasmodesmata. Important molecular events are addressed by re-examining the time-course transcriptome of interfamily grafts, from which we recently identified the cell-cell adhesion mechanism. Plasmodesmata-associated genes upregulated during graft healing that may provide a link to symplasm establishment are described. We also discuss future research directions.
Topics: Plant Cells; Plant Physiological Phenomena; Plasmodesmata; Transplantation
PubMed: 34252186
DOI: 10.1093/pcp/pcab109 -
The New Phytologist Sep 2023Sugar loading of developing seeds comprises a cohort of transport events that contribute to reproductive success and seed yield. Understanding these events is most... (Review)
Review
Sugar loading of developing seeds comprises a cohort of transport events that contribute to reproductive success and seed yield. Understanding these events is most advanced for grain crops (Brassicaceae, Fabaceae and Gramineae) and Arabidopsis. For these species, 75-80% of their final seed biomass is derived from phloem-imported sucrose. Sugar loading consecutively traverses three genomically distinct, and symplasmically isolated, seed domains: maternal pericarp/seed coat, filial endosperm and filial embryo. Sink status of each domain co-ordinately transitions from growth to storage. The latter is dominated by embryos (Brassicaceae and Fabaceae) or endosperms (Gramineae). Intradomain sugar transport occurs symplasmically through plasmodesmata. Interdomain sugar transport relies on plasma-membrane transporters operating in efflux (maternal and endosperm) or influx (endosperm and embryo) modes. Discussed is substantial progress made in identifying, and functionally evaluating, sugar symporters (STPs, SUTs or SUCs) and uniporters (SWEETs). These findings have underpinned a mechanistic understanding of seed loading. Less well researched are possible physical limitations imposed by hydraulic conductivities of differentiating protophloem and of subsequent plasmodesmal transport. The latter is coupled with sugar homeostasis within each domain mediated by sugar transporters. A similar conclusion is ascribed to fragmentary understanding of regulatory mechanisms integrating transport events with seed growth and storage.
Topics: Sugars; Phloem; Plasmodesmata; Biological Transport; Seeds; Membrane Transport Proteins; Arabidopsis; Poaceae; Fabaceae
PubMed: 37306002
DOI: 10.1111/nph.19058 -
Current Opinion in Virology Jun 2021Plant viruses have evolved efficient mechanisms to move cell-to-cell through plasmodesmata (PD) for systemic infection. Potyviruses including many economically important... (Review)
Review
Plant viruses have evolved efficient mechanisms to move cell-to-cell through plasmodesmata (PD) for systemic infection. Potyviruses including many economically important viruses constitute the largest group of known plant-infecting RNA viruses. Potyviral intercellular movement is accomplished by the coordinated action of at least three viral proteins and diverse host components. It requires the viral coat protein and is interlinked with active virus replication that generates, through RNA-polymerase slippage, a small percentage of frameshift viral RNA for the production of another essential movement protein named P3N-PIPO. This PD-located protein targets the virus-encoded cylindrical inclusion protein to PD to form special conical structures for potyviral passage, possibly in the form of virion. Here, I highlight and discuss major advances of potyviral intercellular trafficking.
Topics: Capsid Proteins; Cell Movement; Genome, Viral; Plant Diseases; Plant Viral Movement Proteins; Plant Viruses; Plasmodesmata; Potyvirus; RNA, Viral; Viral Proteins; Virion; Virus Replication
PubMed: 33784579
DOI: 10.1016/j.coviro.2021.03.002 -
Journal of Experimental Botany Dec 2017The infection of plants by viruses depends on cellular mechanisms that support the replication of the viral genomes, and the cell-to-cell and systemic movement of the... (Review)
Review
The infection of plants by viruses depends on cellular mechanisms that support the replication of the viral genomes, and the cell-to-cell and systemic movement of the virus via plasmodesmata (PD) and the connected phloem. While the propagation of some viruses requires the conventional endoplasmic reticulum (ER)-Golgi pathway, others replicate and spread between cells in association with the ER and are independent of this pathway. Using selected viruses as examples, this review re-examines the involvement of membranes and the cytoskeleton during virus infection and proposes potential roles of class VIII myosins and membrane-tethering proteins in controlling viral functions at specific ER subdomains, such as cortical microtubule-associated ER sites, ER-plasma membrane contact sites, and PD.
Topics: Cell Membrane; Cytoskeleton; Endoplasmic Reticulum; Microtubules; Myosins; Plant Diseases; Plant Proteins; Plant Viruses; Plants; Plasmodesmata; Virus Replication
PubMed: 29036578
DOI: 10.1093/jxb/erx334 -
Methods in Molecular Biology (Clifton,... 2022In bryophytes (i.e., mosses, liverworts, and hornworts), extant representatives of early land plants, plasmodesmata have been described in a wide range of tissues....
In bryophytes (i.e., mosses, liverworts, and hornworts), extant representatives of early land plants, plasmodesmata have been described in a wide range of tissues. Although their contribution to bryophyte morphogenesis remains largely unexplored, several recent studies have suggested that the deposition of callose around plasmodesmata might regulate developmental and physiological responses in mosses. In this chapter, we provide a protocol to image and quantify callose levels in the filamentous body of the model moss Physcomitrium (Physcomitrella) patens and discuss possible alternatives and pitfalls. More generally, this protocol establishes a framework to explore the distribution of callose in other bryophytes.
Topics: Bryophyta; Bryopsida; Glucans; Phylogeny; Plasmodesmata
PubMed: 35349140
DOI: 10.1007/978-1-0716-2132-5_11 -
Nature Reviews. Molecular Cell Biology Sep 2004The evolution of intercellular communication had an important role in the increasing complexity of both multicellular and supracellular organisms. Plasmodesmata, the... (Review)
Review
The evolution of intercellular communication had an important role in the increasing complexity of both multicellular and supracellular organisms. Plasmodesmata, the intercellular organelles of the plant kingdom, establish an effective pathway for local and long-distance signalling. In higher plants, this pathway involves the trafficking of proteins and various forms of RNA that function non-cell-autonomously to affect developmental programmes.
Topics: Cell Communication; Green Fluorescent Proteins; Luminescent Proteins; Models, Biological; Plant Development; Plant Diseases; Plant Physiological Phenomena; Plant Proteins; Plants; Plasmodesmata; Protein Transport; RNA, Plant
PubMed: 15340379
DOI: 10.1038/nrm1470 -
Methods in Molecular Biology (Clifton,... 2022Plasmodesmata are nanoscale cell wall channels connecting neighboring cells in plants. Intercellular trafficking of molecules via plasmodesmata plays important roles in...
Plasmodesmata are nanoscale cell wall channels connecting neighboring cells in plants. Intercellular trafficking of molecules via plasmodesmata plays important roles in various developmental processes and stress responses. The turnover of callose, a β-1,3-glucan polysaccharide depositing in the cell wall around plasmodesmata, controls the plasmodesmal permeability and symplasmic transport. Here, we describe a protocol for the spatiotemporally controlled induction of callose synthesis and plasmodesmata closure using the cals3m system. In this system, cals3m, a mutant CALLOSE SYNTHASE 3 (CALS3) gene, is driven by inducible tissue-specific promoters of interest. After appropriate induction by 17-β-estradiol, callose is overproduced within the corresponding specific domains, resulting in temporal closure of plasmodesmata at the cell-cell interfaces. This approach can be used to validate and dissect the function of plasmodesmata-mediated symplasmic communications.
Topics: Cell Wall; Glucans; Glucosyltransferases; Plasmodesmata
PubMed: 35349155
DOI: 10.1007/978-1-0716-2132-5_26 -
Methods in Molecular Biology (Clifton,... 2022An important approach to investigate intercellular connectivity via plasmodesmata is to visualize and track the movement of fluorescent proteins between cells. The...
An important approach to investigate intercellular connectivity via plasmodesmata is to visualize and track the movement of fluorescent proteins between cells. The intercellular connectivity is largely controlled by the size exclusion limit of the pores. Over the past few decades, the technique to observe and analyze intercellular movement of a fluorescent protein has been developed mainly in angiosperms such as Arabidopsis thaliana. We recently applied the corresponding system to track the intercellular movement of the fluorescent protein Dendra2 in the moss Physcomitrium (Physcomitrella) patens. The protonemal tissues are particularly suited for observation of the intercellular movement due to the simple organization. Here, we describe a protocol suitable for the analysis of Dendra2 movement between cells in P. patens.
Topics: Arabidopsis; Bryopsida; Plasmodesmata
PubMed: 35349151
DOI: 10.1007/978-1-0716-2132-5_22