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Tee EE, Faulkner C. Plasmodesmata and intercellular molecular traffic control. THE NEW PHYTOLOGIST 2024; 243:32-47. [PMID: 38494438 DOI: 10.1111/nph.19666] [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: 10/30/2023] [Accepted: 02/13/2024] [Indexed: 03/19/2024]
Abstract
Plasmodesmata are plasma membrane-lined connections that join plant cells to their neighbours, establishing an intercellular cytoplasmic continuum through which molecules can travel between cells, tissues, and organs. As plasmodesmata connect almost all cells in plants, their molecular traffic carries information and resources across a range of scales, but dynamic control of plasmodesmal aperture can change the possible domains of molecular exchange under different conditions. Plasmodesmal aperture is controlled by specialised signalling cascades accommodated in spatially discrete membrane and cell wall domains. Thus, the composition of plasmodesmata defines their capacity for molecular trafficking. Further, their shape and density can likewise define trafficking capacity, with the cell walls between different cell types hosting different numbers and forms of plasmodesmata to drive molecular flux in physiologically important directions. The molecular traffic that travels through plasmodesmata ranges from small metabolites through to proteins, and possibly even larger mRNAs. Smaller molecules are transmitted between cells via passive mechanisms but how larger molecules are efficiently trafficked through plasmodesmata remains a key question in plasmodesmal biology. How plasmodesmata are formed, the shape they take, what they are made of, and what passes through them regulate molecular traffic through plants, underpinning a wide range of plant physiology.
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Affiliation(s)
- Estee E Tee
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Christine Faulkner
- Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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2
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Li J, Yang J, Gao Y, Zhang Z, Gao C, Chen S, Liesche J. Parallel auxin transport via PINs and plasmodesmata during the Arabidopsis leaf hyponasty response. PLANT CELL REPORTS 2023; 43:4. [PMID: 38117314 PMCID: PMC10733227 DOI: 10.1007/s00299-023-03119-1] [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: 07/17/2023] [Accepted: 11/22/2023] [Indexed: 12/21/2023]
Abstract
KEY MESSAGE The leaf hyponasty response depends on tip-to-petiole auxin transport. This transport can happen through two parallel pathways: active trans-membrane transport mediated by PIN proteins and passive diffusion through plasmodesmata. A plant's ability to counteract potential shading by neighboring plants depends on transport of the hormone auxin. Neighbor sensing at the leaf tip triggers auxin production. Once this auxin reaches the abaxial petiole epidermis, it causes cell elongation, which leads to leaf hyponasty. Two pathways are known to contribute to this intercellular tip-to-petiole auxin movement: (i) transport facilitated by plasma membrane-localized PIN auxin transporters and (ii) diffusion enabled by plasmodesmata. We tested if these two modes of transport are arranged sequentially or in parallel. Moreover, we investigated if they are functionally linked. Mutants in which one of the two pathways is disrupted indicated that both pathways are necessary for a full hyponasty response. Visualization of PIN3-GFP and PIN7-GFP localization indicated PIN-mediated transport in parallel to plasmodesmata-mediated transport along abaxial midrib epidermis cells. We found plasmodesmata-mediated cell coupling in the pin3pin4pin7 mutant to match wild-type levels, indicating no redundancy between pathways. Similarly, PIN3, PIN4 and PIN7 mRNA levels were unaffected in a mutant with disrupted plasmodesmata pathway. Our results provide mechanistic insight on leaf hyponasty, which might facilitate the manipulation of the shade avoidance response in crops.
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Affiliation(s)
- Jiazhou Li
- College of Life Sciences, Northwest A & F University, Yangling, 712100, China
- Biomass Energy Center for Arid and Semiarid Lands, Northwest A & F University, Yangling, 712100, China
- State Key Laboratory of Stress Biology for Arid Areas, Northwest A & F University, Yangling, 712100, China
| | - Jintao Yang
- College of Life Sciences, Northwest A & F University, Yangling, 712100, China
- Biomass Energy Center for Arid and Semiarid Lands, Northwest A & F University, Yangling, 712100, China
- State Key Laboratory of Stress Biology for Arid Areas, Northwest A & F University, Yangling, 712100, China
| | - Yibo Gao
- College of Life Sciences, Northwest A & F University, Yangling, 712100, China
| | - Ziyu Zhang
- College of Life Sciences, Northwest A & F University, Yangling, 712100, China
| | - Chen Gao
- Institute for Molecular Physiology, University of Düsseldorf, 40225, Düsseldorf, Germany
| | - Shaolin Chen
- College of Life Sciences, Northwest A & F University, Yangling, 712100, China
- Biomass Energy Center for Arid and Semiarid Lands, Northwest A & F University, Yangling, 712100, China
| | - Johannes Liesche
- College of Life Sciences, Northwest A & F University, Yangling, 712100, China.
- Biomass Energy Center for Arid and Semiarid Lands, Northwest A & F University, Yangling, 712100, China.
- State Key Laboratory of Stress Biology for Arid Areas, Northwest A & F University, Yangling, 712100, China.
- Institute of Biology, University of Graz, Schubertstraße 51, 8010, Graz, Austria.
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3
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Mäkinen K, Aspelin W, Pollari M, Wang L. How do they do it? The infection biology of potyviruses. Adv Virus Res 2023; 117:1-79. [PMID: 37832990 DOI: 10.1016/bs.aivir.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2023]
Affiliation(s)
- Kristiina Mäkinen
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.
| | - William Aspelin
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Maija Pollari
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Linping Wang
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
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Husted S, Minutello F, Pinna A, Tougaard SL, Møs P, Kopittke PM. What is missing to advance foliar fertilization using nanotechnology? TRENDS IN PLANT SCIENCE 2023; 28:90-105. [PMID: 36153275 DOI: 10.1016/j.tplants.2022.08.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 08/11/2022] [Accepted: 08/19/2022] [Indexed: 06/16/2023]
Abstract
An urgent challenge within agriculture is to improve fertilizer efficiency in order to reduce the environmental footprint associated with an increased production of crops on existing farmland. Standard soil fertilization strategies are often not very efficient due to immobilization in the soil and losses of nutrients by leaching or volatilization. Foliar fertilization offers an attractive supplementary strategy as it bypasses the adverse soil processes, but implementation is often hampered by a poor penetration through leaf barriers, leaf damage, and a limited ability of nutrients to translocate. Recent advances within bionanotechnology offer a range of emerging possibilities to overcome these challenges. Here we review how nanoparticles can be tailored with smart properties to interact with plant tissue for a more efficient delivery of nutrients.
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Affiliation(s)
- Søren Husted
- University of Copenhagen, Department of Plant and Environmental Sciences, Copenhagen Plant Science Center, DK-1871 Frederiksberg C, Denmark.
| | - Francesco Minutello
- University of Copenhagen, Department of Plant and Environmental Sciences, Copenhagen Plant Science Center, DK-1871 Frederiksberg C, Denmark
| | - Andrea Pinna
- University of Copenhagen, Department of Plant and Environmental Sciences, Copenhagen Plant Science Center, DK-1871 Frederiksberg C, Denmark
| | - Stine Le Tougaard
- University of Copenhagen, Department of Plant and Environmental Sciences, Copenhagen Plant Science Center, DK-1871 Frederiksberg C, Denmark
| | - Pauline Møs
- University of Copenhagen, Department of Plant and Environmental Sciences, Copenhagen Plant Science Center, DK-1871 Frederiksberg C, Denmark
| | - Peter M Kopittke
- The University of Queensland, School of Agriculture and Food Sciences, St Lucia 4072, Queensland, Australia
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5
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Pleyerová I, Hamet J, Konrádová H, Lipavská H. Versatile roles of sorbitol in higher plants: luxury resource, effective defender or something else? PLANTA 2022; 256:13. [PMID: 35713726 DOI: 10.1007/s00425-022-03925-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/21/2022] [Indexed: 06/15/2023]
Abstract
Sorbitol metabolism plays multiple roles in many plants, including energy and carbon enrichment, effective defence against various stresses and other emerging specific roles. The underlying mechanisms are, however, incompletely understood. This review provides the current state-of-the-art, highlights missing knowledge and poses several remaining questions. The basic properties of sugar alcohols are summarised and pathways of sorbitol metabolism, including biosynthesis, degradation and key enzymes are described. Sorbitol transport within the plant body is discussed and individual roles of sorbitol in different organs, specific cells or even cellular compartments, are elaborated, clarifying the critical importance of sorbitol allocation and distribution. In addition to plants that accumulate and transport significant quantities of sorbitol (usual producers), there are some that synthesize small amounts of sorbitol or only possess sorbitol metabolising enzymes (non-usual producers). Modern analytical methods have recently enabled large amounts of data to be acquired on this topic, although numerous uncertainties and questions remain. For a long time, it has been clear that enriching carbohydrate metabolism with a sorbitol branch improves plant fitness under stress. Nevertheless, this is probably valid only when appropriate growth and defence trade-offs are ensured. Information on the ectopic expression of sorbitol metabolism genes has contributed substantially to our understanding of the sorbitol roles and raises new questions regarding sorbitol signalling potential. We finally examine strategies in plants producing sorbitol compared with those producing mannitol. Providing an in-depth understanding of sugar alcohol metabolism is essential for the progress in plant physiology as well as in targeted, knowledge-based crop breeding.
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Affiliation(s)
- Iveta Pleyerová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 43, Prague 2, Czech Republic
| | - Jaromír Hamet
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 43, Prague 2, Czech Republic
| | - Hana Konrádová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 43, Prague 2, Czech Republic.
| | - Helena Lipavská
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 43, Prague 2, Czech Republic
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Zhang Y, Lu Y, El Sayyed H, Bian J, Lin J, Li X. Transcription factor dynamics in plants: Insights and technologies for in vivo imaging. PLANT PHYSIOLOGY 2022; 189:23-36. [PMID: 35134239 PMCID: PMC9070795 DOI: 10.1093/plphys/kiac042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 01/08/2022] [Indexed: 06/14/2023]
Abstract
Biochemical and genetic approaches have been extensively used to study transcription factor (TF) functions, but their dynamic behaviors and the complex ways in which they regulate transcription in plant cells remain unexplored, particularly behaviors such as translocation and binding to DNA. Recent developments in labeling and imaging techniques provide the necessary sensitivity and resolution to study these behaviors in living cells. In this review, we present an up-to-date portrait of the dynamics and regulation of TFs under physiologically relevant conditions and then summarize recent advances in fluorescent labeling strategies and imaging techniques. We then discuss future prospects and challenges associated with the application of these techniques to examine TFs' intricate dance in living plants.
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Affiliation(s)
- Yuan Zhang
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
| | - Yuqing Lu
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
| | - Hafez El Sayyed
- Department of Physics, University of Oxford, Oxford OX1 3PU, UK
| | - Jiahui Bian
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
| | - Jinxing Lin
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
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7
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Miras M, Pottier M, Schladt TM, Ejike JO, Redzich L, Frommer WB, Kim JY. Plasmodesmata and their role in assimilate translocation. JOURNAL OF PLANT PHYSIOLOGY 2022; 270:153633. [PMID: 35151953 DOI: 10.1016/j.jplph.2022.153633] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 01/26/2022] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
During multicellularization, plants evolved unique cell-cell connections, the plasmodesmata (PD). PD of angiosperms are complex cellular domains, embedded in the cell wall and consisting of multiple membranes and a large number of proteins. From the beginning, it had been assumed that PD provide passage for a wide range of molecules, from ions to metabolites and hormones, to RNAs and even proteins. In the context of assimilate allocation, it has been hypothesized that sucrose produced in mesophyll cells is transported via PD from cell to cell down a concentration gradient towards the phloem. Entry into the sieve element companion cell complex (SECCC) is then mediated on three potential routes, depending on the species and conditions, - either via diffusion across PD, after conversion to raffinose via PD using a polymer trap mechanism, or via a set of transporters which secrete sucrose from one cell and secondary active uptake into the SECCC. Multiple loading mechanisms can likely coexist. We here review the current knowledge regarding photoassimilate transport across PD between cells as a prerequisite for translocation from leaves to recipient organs, in particular roots and developing seeds. We summarize the state-of-the-art in protein composition, structure, transport mechanism and regulation of PD to apprehend their functions in carbohydrate allocation. Since many aspects of PD biology remain elusive, we highlight areas that require new approaches and technologies to advance our understanding of these enigmatic and important cell-cell connections.
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Affiliation(s)
- Manuel Miras
- Institute for Molecular Physiology, Heinrich-Heine-University Düsseldorf, Düsseldorf, 40225, Germany
| | - Mathieu Pottier
- Institute for Molecular Physiology, Heinrich-Heine-University Düsseldorf, Düsseldorf, 40225, Germany
| | - T Moritz Schladt
- Institute for Molecular Physiology, Heinrich-Heine-University Düsseldorf, Düsseldorf, 40225, Germany
| | - J Obinna Ejike
- Institute for Molecular Physiology and Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University Düsseldorf, Düsseldorf, 40225, Germany
| | - Laura Redzich
- Institute for Molecular Physiology and Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University Düsseldorf, Düsseldorf, 40225, Germany
| | - Wolf B Frommer
- Institute for Molecular Physiology and Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University Düsseldorf, Düsseldorf, 40225, Germany; Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya, 464-8601, Japan.
| | - Ji-Yun Kim
- Institute for Molecular Physiology and Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University Düsseldorf, Düsseldorf, 40225, Germany
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8
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Deinum EE. More Insights from Ultrastructural and Functional Plasmodesmata Data Using PDinsight. Methods Mol Biol 2022; 2457:443-456. [PMID: 35349159 DOI: 10.1007/978-1-0716-2132-5_30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
PDinsight is a Python-based tool for computing effective wall permeability for symplasmic transport based on plasmodesma (PD) size and distribution data. PDinsight can be used for direct computation of such permeabilities if full data is available, as well as in an explorative way if some data is either not available or considered unreliable. In this chapter, we briefly describe the basic model underlying the PDinsight calculations and discuss how the different modes of PDinsight can be used in relation to typical research questions. We also offer advice on choosing appropriate values for diffusion coefficients and particle size based on the currently most used experimental probes.
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Affiliation(s)
- Eva E Deinum
- Wageningen University, Wageningen, The Netherlands.
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9
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Gersony JT, McClelland A, Holbrook NM. Raman spectroscopy reveals high phloem sugar content in leaves of canopy red oak trees. THE NEW PHYTOLOGIST 2021; 232:418-424. [PMID: 33991343 DOI: 10.1111/nph.17465] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
A robust understanding of phloem functioning in tall trees evades us because current methods for collecting phloem sap do not lend themselves to measuring actively photosynthesizing canopy leaves. We show that Raman spectroscopy can be used as a quantitative tool to assess sucrose concentration in leaf samples. Specifically, we found that Raman spectroscopy can predict physiologically relevant sucrose concentrations (adjusted R2 of 0.9) in frozen leaf extract spiked with sucrose. We then apply this method to estimate sieve element sucrose concentration in rapidly frozen petioles of canopy red oak (Quercus rubra) trees and found that sucrose concentrations are > 1100 mM at midday and midnight. This concentration is predicted to generate a sieve element turgor pressure high enough to generate bulk flow through the phloem, but is potentially too high to allow for sucrose diffusion from photosynthetic cells. Our findings support the Münch hypothesis for phloem transport once the carbon is in the phloem and challenge the passive-loading hypothesis for carbon movement into the phloem for red oak. This study provides the first ˜in-situ (frozen in the functioning state) source sieve element sucrose concentration characterization in any plant, opening a new avenue for investigation of phloem functioning.
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Affiliation(s)
- Jess T Gersony
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Arthur McClelland
- Center for Nanoscale Systems, Harvard University, Cambridge, MA, 02138, USA
| | - N Michele Holbrook
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
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Barceló-Anguiano M, Holbrook NM, Hormaza JI, Losada JM. Changes in ploidy affect vascular allometry and hydraulic function in Mangifera indica trees. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:541-554. [PMID: 34403543 DOI: 10.1111/tpj.15460] [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: 06/14/2021] [Revised: 08/09/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
The enucleated vascular elements of the xylem and the phloem offer an excellent system to test the effect of ploidy on plant function because variation in vascular geometry has a direct influence on transport efficiency. However, evaluations of conduit sizes in polyploid plants have remained elusive, most remarkably in woody species. We used a combination of molecular, physiological and microscopy techniques to model the hydraulic resistance between source and sinks in tetraploid and diploid mango trees. Tetraploids exhibited larger chloroplasts, mesophyll cells and stomatal guard cells, resulting in higher leaf elastic modulus and lower dehydration rates, despite the high water potentials of both ploidies in the field. Both the xylem and the phloem displayed a scaling of conduits with ploidy, revealing attenuated hydraulic resistance in tetraploids. Conspicuous wall hygroscopic moieties in the cells involved in transpiration and transport indicate a role in volumetric adjustments as a result of turgor change in both ploidies. In autotetraploids, the enlargement of organelles, cells and tissues, which are critical for water and photoassimilate transport at long distances, point to major physiological novelties associated with whole-genome duplication.
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Affiliation(s)
- Miguel Barceló-Anguiano
- Institute for Mediterranean and Subtropical Horticulture 'La Mayora' - CSIC - UMA, Avda. Dr. Wienberg s/n, Málaga, 29750, Spain
| | - N Michele Holbrook
- Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, Massachusetts, 02138, USA
| | - José I Hormaza
- Institute for Mediterranean and Subtropical Horticulture 'La Mayora' - CSIC - UMA, Avda. Dr. Wienberg s/n, Málaga, 29750, Spain
| | - Juan M Losada
- Institute for Mediterranean and Subtropical Horticulture 'La Mayora' - CSIC - UMA, Avda. Dr. Wienberg s/n, Málaga, 29750, Spain
- Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, Massachusetts, 02138, USA
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Li Y, Jiao M, Li Y, Zhong Y, Li X, Chen Z, Chen S, Wang J. Penicillium chrysogenum polypeptide extract protects tobacco plants from tobacco mosaic virus infection through modulation of ABA biosynthesis and callose priming. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:3526-3539. [PMID: 33687058 PMCID: PMC8096601 DOI: 10.1093/jxb/erab102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 03/02/2021] [Indexed: 05/26/2023]
Abstract
The polypeptide extract of the dry mycelium of Penicillium chrysogenum (PDMP) can protect tobacco plants from tobacco mosaic virus (TMV), although the mechanism underlying PDMP-mediated TMV resistance remains unknown. In our study, we analysed a potential mechanism via RNA sequencing (RNA-seq) and found that the abscisic acid (ABA) biosynthetic pathway and β-1,3-glucanase, a callose-degrading enzyme, might play an important role in PDMP-induced priming of resistance to TMV. To test our hypothesis, we successfully generated a Nicotiana benthamiana ABA biosynthesis mutant and evaluated the role of the ABA pathway in PDMP-induced callose deposition during resistance to TMV infection. Our results suggested that PDMP can induce callose priming to defend against TMV movement. PDMP inhibited TMV movement by increasing callose deposition around plasmodesmata, but this phenomenon did not occur in the ABA biosynthesis mutant; moreover, these effects of PDMP on callose deposition could be rescued by treatment with exogenous ABA. Our results suggested that callose deposition around plasmodesmata in wild-type plants is mainly responsible for the restriction of TMV movement during the PDMP-induced defensive response to TMV infection, and that ABA biosynthesis apparently plays a crucial role in PDMP-induced callose priming for enhancing defence against TMV.
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Affiliation(s)
- Yu Li
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Mengting Jiao
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Yingjuan Li
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Yu Zhong
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Xiaoqin Li
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Zhuangzhuang Chen
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Suiyun Chen
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
| | - Jianguang Wang
- Biocontrol Engineering Research Center of Crop Disease & Pest of Yunnan Province, School of Life Science, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Plant Disease & Pest, School of Life Science, Yunnan University, Kunming, China
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12
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Wang G, Wu Y, Ma L, Lin Y, Hu Y, Li M, Li W, Ding Y, Chen L. Phloem loading in rice leaves depends strongly on the apoplastic pathway. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:3723-3738. [PMID: 33624763 DOI: 10.1093/jxb/erab085] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 02/19/2021] [Indexed: 06/12/2023]
Abstract
Phloem loading is the first step in sucrose transport from source leaves to sink organs. The phloem loading strategy in rice remains unclear. To determine the potential phloem loading mechanism in rice, yeast invertase (INV) was overexpressed by a 35S promoter specifically in the cell wall to block sugar transmembrane loading in rice. The transgenic lines exhibited obvious phloem loading suppression characteristics accompanied by the accumulation of sucrose and starch, restricted vegetative growth and decreased grain yields. The decreased sucrose exudation rate with p-chloromercuribenzenesulfonic acid (PCMBS) treatment also indicated that rice actively transported sucrose into the phloem. OsSUT1 (SUCROSE TRANSPORTER 1) showed the highest mRNA levels of the plasma membrane-localized OsSUTs in source leaves. Cross sections of the OsSUT::GUS transgenic plants showed that the expression of OsSUT1 and OsSUT5 occurred in the phloem companion cells. Rice ossut1 mutants showed reduced growth and grain yield, supporting the hypothesis of OsSUT1 acting in phloem loading. Based on these results, we conclude that apoplastic phloem loading plays a major role in the export of sugar from rice leaves.
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Affiliation(s)
- Gaopeng Wang
- College of Agriculture, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Crop Physiology & Ecology in Southern China, Ministry of Agricultural University, Nanjing, China
| | - Yue Wu
- College of Agriculture, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Crop Physiology & Ecology in Southern China, Ministry of Agricultural University, Nanjing, China
| | - Li Ma
- College of Agriculture, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Crop Physiology & Ecology in Southern China, Ministry of Agricultural University, Nanjing, China
| | - Yan Lin
- College of Agriculture, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Crop Physiology & Ecology in Southern China, Ministry of Agricultural University, Nanjing, China
| | - Yuxiang Hu
- College of Agriculture, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Crop Physiology & Ecology in Southern China, Ministry of Agricultural University, Nanjing, China
| | - Mengzhu Li
- College of Agriculture, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Crop Physiology & Ecology in Southern China, Ministry of Agricultural University, Nanjing, China
| | - Weiwei Li
- College of Agriculture, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Crop Physiology & Ecology in Southern China, Ministry of Agricultural University, Nanjing, China
| | - Yanfeng Ding
- College of Agriculture, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Crop Physiology & Ecology in Southern China, Ministry of Agricultural University, Nanjing, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing, China
| | - Lin Chen
- College of Agriculture, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Crop Physiology & Ecology in Southern China, Ministry of Agricultural University, Nanjing, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing, China
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13
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Peters WS, Jensen KH, Stone HA, Knoblauch M. Plasmodesmata and the problems with size: Interpreting the confusion. JOURNAL OF PLANT PHYSIOLOGY 2021; 257:153341. [PMID: 33388666 DOI: 10.1016/j.jplph.2020.153341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 05/14/2023]
Abstract
Plant tissues exhibit a symplasmic organization; the individual protoplasts are connected to their neighbors via cytoplasmic bridges that extend through pores in the cell walls. These bridges may have diameters of a micrometer or more, as in the sieve pores of the phloem, but in most cell types they are smaller. Historically, botanists referred to cytoplasmic bridges of all sizes as plasmodesmata. The meaning of the term began to shift when the transmission electron microscope (TEM) became the preferred tool for studying these structures. Today, a plasmodesma is widely understood to be a 'nano-scale' pore. Unfortunately, our understanding of these nanoscopic channels suffers from methodological limitations. This is exemplified by the fact that state-of-the-art EM techniques appear to reveal plasmodesmal pore structures that are much smaller than the tracer molecules known to diffuse through these pores. In general, transport processes in pores that have dimensions in the size range of the transported molecules are governed by different physical parameters than transport process in the macroscopic realm. This can lead to unexpected effects, as experience in nanofluidic technologies demonstrates. Our discussion of problems of size in plasmodesma research leads us to conclude that the field will benefit from technomimetic reasoning - the utilization of concepts developed in applied nanofluidics for the interpretation of biological systems.
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Affiliation(s)
- Winfried S Peters
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA; Department of Biology, Purdue University Fort Wayne, Fort Wayne, IN, 46805, USA.
| | - Kaare H Jensen
- Department of Physics, Technical University of Denmark, DK-2800 Kgs., Lyngby, Denmark.
| | - Howard A Stone
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, 08544, USA.
| | - Michael Knoblauch
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA.
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14
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Lazareva EA, Lezzhov AA, Chergintsev DA, Golyshev SA, Dolja VV, Morozov SY, Heinlein M, Solovyev AG. Reticulon-like properties of a plant virus-encoded movement protein. THE NEW PHYTOLOGIST 2021; 229:1052-1066. [PMID: 32866987 DOI: 10.1111/nph.16905] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/20/2020] [Indexed: 06/11/2023]
Abstract
Plant viruses encode movement proteins (MPs) that ensure the transport of viral genomes through plasmodesmata (PD) and use cell endomembranes, mostly the endoplasmic reticulum (ER), for delivery of viral genomes to PD and formation of PD-anchored virus replication compartments. Here, we demonstrate that the Hibiscus green spot virus BMB2 MP, an integral ER protein, induces constrictions of ER tubules, decreases the mobility of ER luminal content, and exhibits an affinity to highly curved membranes. These properties are similar to those described for reticulons, cellular proteins that induce membrane curvature to shape the ER tubules. Similar to reticulons, BMB2 adopts a W-like topology within the ER membrane. BMB2 targets PD and increases their size exclusion limit, and these BMB2 activities correlate with the ability to induce constrictions of ER tubules. We propose that the induction of ER constrictions contributes to the BMB2-dependent increase in PD permeability and formation of the PD-associated replication compartments, therefore facilitating the virus intercellular spread. Furthermore, we show that the ER tubule constrictions also occur in cells expressing TGB2, one of the three MPs of Potato virus X (PVX), and in PVX-infected cells, suggesting that reticulon-like MPs are employed by diverse RNA viruses.
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Affiliation(s)
- Ekaterina A Lazareva
- Department of Virology, Biological Faculty, Moscow State University, Moscow, 119234, Russia
| | - Alexander A Lezzhov
- Faculty of Bioengineering and Bioinformatics, Moscow State University, Moscow, 119991, Russia
| | - Denis A Chergintsev
- Department of Plant Physiology, Biological Faculty, Moscow State University, Moscow, 119234, Russia
| | - Sergei A Golyshev
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia
| | - Valerian V Dolja
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA
| | - Sergey Y Morozov
- Department of Virology, Biological Faculty, Moscow State University, Moscow, 119234, Russia
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia
| | - Manfred Heinlein
- Institute for Plant Molecular Biology (IBMP-CNRS), University of Strasbourg, Strasbourg, 67000, France
| | - Andrey G Solovyev
- Department of Virology, Biological Faculty, Moscow State University, Moscow, 119234, Russia
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, 119991, Russia
- Institute of Agricultural Biotechnology, Russian Academy of Agricultural Sciences, Moscow, 127550, Russia
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15
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Abstract
The modern view of the mechanism of intercellular movement of viruses is based largely on data from the study of the tobacco mosaic virus (TMV) 30-kDa movement protein (MP). The discovered properties and abilities of TMV MP, namely, (a) in vitro binding of single-stranded RNA in a non-sequence-specific manner, (b) participation in the intracellular trafficking of genomic RNA to the plasmodesmata (Pd), and (c) localization in Pd and enhancement of Pd permeability, have been used as a reference in the search and analysis of candidate proteins from other plant viruses. Nevertheless, although almost four decades have passed since the introduction of the term “movement protein” into scientific circulation, the mechanism underlying its function remains unclear. It is unclear why, despite the absence of homology, different MPs are able to functionally replace each other in trans-complementation tests. Here, we consider the complexity and contradictions of the approaches for assessment of the ability of plant viral proteins to perform their movement function. We discuss different aspects of the participation of MP and MP/vRNA complexes in intra- and intercellular transport. In addition, we summarize the essential MP properties for their functioning as “conditioners”, creating a favorable environment for viral reproduction.
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16
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Gao C, Liu X, De Storme N, Jensen KH, Xu Q, Yang J, Liu X, Chen S, Martens HJ, Schulz A, Liesche J. Directionality of Plasmodesmata-Mediated Transport in Arabidopsis Leaves Supports Auxin Channeling. Curr Biol 2020; 30:1970-1977.e4. [DOI: 10.1016/j.cub.2020.03.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 02/09/2020] [Accepted: 03/06/2020] [Indexed: 01/12/2023]
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17
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Plasmodesmata Conductivity Regulation: A Mechanistic Model. PLANTS 2019; 8:plants8120595. [PMID: 31842374 PMCID: PMC6963776 DOI: 10.3390/plants8120595] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/03/2019] [Accepted: 12/10/2019] [Indexed: 01/16/2023]
Abstract
Plant cells form a multicellular symplast via cytoplasmic bridges called plasmodesmata (Pd) and the endoplasmic reticulum (ER) that crosses almost all plant tissues. The Pd proteome is mainly represented by secreted Pd-associated proteins (PdAPs), the repertoire of which quickly adapts to environmental conditions and responds to biotic and abiotic stresses. Although the important role of Pd in stress-induced reactions is universally recognized, the mechanisms of Pd control are still not fully understood. The negative role of callose in Pd permeability has been convincingly confirmed experimentally, yet the roles of cytoskeletal elements and many PdAPs remain unclear. Here, we discuss the contribution of each protein component to Pd control. Based on known data, we offer mechanistic models of mature leaf Pd regulation in response to stressful effects.
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18
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Deinum EE, Mulder BM, Benitez-Alfonso Y. From plasmodesma geometry to effective symplasmic permeability through biophysical modelling. eLife 2019; 8:49000. [PMID: 31755863 PMCID: PMC6994222 DOI: 10.7554/elife.49000] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 11/16/2019] [Indexed: 12/12/2022] Open
Abstract
Regulation of molecular transport via intercellular channels called plasmodesmata (PDs) is important for both coordinating developmental and environmental responses among neighbouring cells, and isolating (groups of) cells to execute distinct programs. Cell-to-cell mobility of fluorescent molecules and PD dimensions (measured from electron micrographs) are both used as methods to predict PD transport capacity (i.e., effective symplasmic permeability), but often yield very different values. Here, we build a theoretical bridge between both experimental approaches by calculating the effective symplasmic permeability from a geometrical description of individual PDs and considering the flow towards them. We find that a dilated central region has the strongest impact in thick cell walls and that clustering of PDs into pit fields strongly reduces predicted permeabilities. Moreover, our open source multi-level model allows to predict PD dimensions matching measured permeabilities and add a functional interpretation to structural differences observed between PDs in different cell walls.
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Affiliation(s)
- Eva E Deinum
- Mathematical and statistical methods (Biometris), Wageningen University, Wageningen, Netherlands
| | - Bela M Mulder
- Living Matter Department, Institute AMOLF, Amsterdam, Netherlands.,Laboratory of Cell Biology, Wageningen University, Wageningen, Netherlands
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19
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Quantification of Symplasmic Phloem Loading Capacity with Live-Cell Microscopy. Methods Mol Biol 2019. [PMID: 31197799 DOI: 10.1007/978-1-4939-9562-2_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Sugars produced by photosynthesis in leaves get transported to other organs in the phloem vascular tissue. Three general mechanisms have been proposed for the loading of sugars into the phloem. These differ in the involvement of active transport across the phloem cell's membrane and their capacity for passive intercellular transport through plasmodesmata. This capacity for diffusion from the mesophyll into the phloem cells can be quantified by live-cell microscopy. Instead of sugar molecules, the movement of fluorescent tracers of similar size can be observed. In this chapter, a simple method is described that allows quantification of plasmodesmata-mediated intercellular diffusion across the mesophyll-bundle sheath interface and the bundle sheath-phloem cell interfaces. The fluorescent tracer carboxyfluorescein is loaded into intact leaves and its diffusion monitored with confocal microscopy after photobleaching of a bundle sheath cell.
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