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Chen J, Xu X, Liu W, Feng Z, Chen Q, Zhou Y, Sun M, Gan L, Zhou T, Xuan Y. Plasmodesmata Function and Callose Deposition in Plant Disease Defense. PLANTS (BASEL, SWITZERLAND) 2024; 13:2242. [PMID: 39204678 PMCID: PMC11359699 DOI: 10.3390/plants13162242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 08/02/2024] [Accepted: 08/06/2024] [Indexed: 09/04/2024]
Abstract
Callose, found in the cell walls of higher plants such as β-1,3-glucan with β-1,6 branches, is pivotal for both plant development and responses to biotic and abiotic stressors. Plasmodesmata (PD), membranous channels linking the cytoplasm, plasma membrane, and endoplasmic reticulum of adjacent cells, facilitate molecular transport, crucial for developmental and physiological processes. The regulation of both the structural and transport functions of PD is intricate. The accumulation of callose in the PD neck is particularly significant for the regulation of PD permeability. This callose deposition, occurring at a specific site of pathogenic incursion, decelerates the invasion and proliferation of pathogens by reducing the PD pore size. Scholarly investigations over the past two decades have illuminated pathogen-induced callose deposition and the ensuing PD regulation. This gradual understanding reveals the complex regulatory interactions governing defense-related callose accumulation and protein-mediated PD regulation, underscoring its role in plant defense. This review systematically outlines callose accumulation mechanisms and enzymatic regulation in plant defense and discusses PD's varied participation against viral, fungal, and bacterial infestations. It scrutinizes callose-induced structural changes in PD, highlighting their implications for plant immunity. This review emphasizes dynamic callose calibration in PD constrictions and elucidates the implications and potential challenges of this intricate defense mechanism, integral to the plant's immune system.
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Affiliation(s)
- Jingsheng Chen
- College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404100, China; (J.C.); (W.L.); (Z.F.); (Q.C.); (M.S.); (L.G.)
| | - Xiaofeng Xu
- College of Plant Protection, Northeast Agricultural University, Harbin 150030, China;
| | - Wei Liu
- College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404100, China; (J.C.); (W.L.); (Z.F.); (Q.C.); (M.S.); (L.G.)
| | - Ziyang Feng
- College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404100, China; (J.C.); (W.L.); (Z.F.); (Q.C.); (M.S.); (L.G.)
| | - Quan Chen
- College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404100, China; (J.C.); (W.L.); (Z.F.); (Q.C.); (M.S.); (L.G.)
| | - You Zhou
- College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404100, China; (J.C.); (W.L.); (Z.F.); (Q.C.); (M.S.); (L.G.)
| | - Miao Sun
- College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404100, China; (J.C.); (W.L.); (Z.F.); (Q.C.); (M.S.); (L.G.)
| | - Liping Gan
- College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing 404100, China; (J.C.); (W.L.); (Z.F.); (Q.C.); (M.S.); (L.G.)
| | - Tiange Zhou
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China
| | - Yuanhu Xuan
- State Key Laboratory of Elemento-Organic Chemistry, Department of Chemical Biology, National Pesticide Engineering Research Center (Tianjin), Nankai University, Tianjin 300071, China;
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2
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Wegner L, Ehlers K. Plasmodesmata dynamics in bryophyte model organisms: secondary formation and developmental modifications of structure and function. PLANTA 2024; 260:45. [PMID: 38965075 PMCID: PMC11224097 DOI: 10.1007/s00425-024-04476-1] [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: 03/25/2024] [Accepted: 06/25/2024] [Indexed: 07/06/2024]
Abstract
MAIN CONCLUSION Developing bryophytes differentially modify their plasmodesmata structure and function. Secondary plasmodesmata formation via twinning appears to be an ancestral trait. Plasmodesmata networks in hornwort sporophyte meristems resemble those of angiosperms. All land-plant taxa use plasmodesmata (PD) cell connections for symplasmic communication. In angiosperm development, PD networks undergo an extensive remodeling by structural and functional PD modifications, and by postcytokinetic formation of additional secondary PD (secPD). Since comparable information on PD dynamics is scarce for the embryophyte sister groups, we investigated maturating tissues of Anthoceros agrestis (hornwort), Physcomitrium patens (moss), and Marchantia polymorpha (liverwort). As in angiosperms, quantitative electron microscopy revealed secPD formation via twinning in gametophytes of all model bryophytes, which gives rise to laterally adjacent PD pairs or to complex branched PD. This finding suggests that PD twinning is an ancient evolutionary mechanism to adjust PD numbers during wall expansion. Moreover, all bryophyte gametophytes modify their existing PD via taxon-specific strategies resembling those of angiosperms. Development of type II-like PD morphotypes with enlarged diameters or formation of pit pairs might be required to maintain PD transport rates during wall thickening. Similar to angiosperm leaves, fluorescence redistribution after photobleaching revealed a considerable reduction of the PD permeability in maturating P. patens phyllids. In contrast to previous reports on monoplex meristems of bryophyte gametophytes with single initials, we observed targeted secPD formation in the multi-initial basal meristems of A. agrestis sporophytes. Their PD networks share typical features of multi-initial angiosperm meristems, which may hint at a putative homologous origin. We also discuss that monoplex and multi-initial meristems may require distinct types of PD networks, with or without secPD formation, to control maintenance of initial identity and positional signaling.
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Affiliation(s)
- Linus Wegner
- Institute of Botany, Justus-Liebig University, 35392, Giessen, Germany.
| | - Katrin Ehlers
- Institute of Botany, Justus-Liebig University, 35392, Giessen, Germany.
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3
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Bayer EM, Benitez-Alfonso Y. Plasmodesmata: Channels Under Pressure. ANNUAL REVIEW OF PLANT BIOLOGY 2024; 75:291-317. [PMID: 38424063 DOI: 10.1146/annurev-arplant-070623-093110] [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] [Indexed: 03/02/2024]
Abstract
Multicellularity has emerged multiple times in evolution, enabling groups of cells to share a living space and reducing the burden of solitary tasks. While unicellular organisms exhibit individuality and independence, cooperation among cells in multicellular organisms brings specialization and flexibility. However, multicellularity also necessitates intercellular dependence and relies on intercellular communication. In plants, this communication is facilitated by plasmodesmata: intercellular bridges that allow the direct (cytoplasm-to-cytoplasm) transfer of information between cells. Plasmodesmata transport essential molecules that regulate plant growth, development, and stress responses. They are embedded in the extracellular matrix but exhibit flexibility, adapting intercellular flux to meet the plant's needs.In this review, we delve into the formation and functionality of plasmodesmata and examine the capacity of the plant communication network to respond to developmental and environmental cues. We illustrate how environmental pressure shapes cellular interactions and aids the plant in adapting its growth.
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Affiliation(s)
- Emmanuelle M Bayer
- Laboratoire de Biogenèse Membranaire (LBM), CNRS UMR5200, Université de Bordeaux, Villenave D'Ornon, France;
| | - Yoselin Benitez-Alfonso
- School of Biology, Centre for Plant Sciences, and Astbury Centre, University of Leeds, Leeds, United Kingdom;
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4
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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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5
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Chen X, Li WW, Gao J, Wu Z, Du J, Zhang X, Zhu YX. Arabidopsis PDLP7 modulated plasmodesmata function is related to BG10-dependent glucosidase activity required for callose degradation. Sci Bull (Beijing) 2024:S2095-9273(24)00312-8. [PMID: 38735789 DOI: 10.1016/j.scib.2024.04.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 04/01/2024] [Accepted: 04/25/2024] [Indexed: 05/14/2024]
Abstract
The microdomains of plasmodesmata, specialized cell-wall channels responsible for communications between neighboring cells, are composed of various plasmodesmata-located proteins (PDLPs) and lipids. Here, we found that, among all PDLP or homologous proteins in Arabidopsis thaliana genome, PDLP5 and PDLP7 possessed a C-terminal sphingolipid-binding motif, with the latter being the only member that was significantly upregulated upon turnip mosaic virus and cucumber mosaic virus infections. pdlp7 mutant plants exhibited significantly reduced callose deposition, larger plasmodesmata diameters, and faster viral transmission. These plants exhibited increased glucosidase activity but no change in callose synthase activity. PDLP7 interacted specifically with glucan endo-1,3-β-glucosidase 10 (BG10). Consistently, higher levels of callose deposition and slower virus transmission in bg10 mutants were observed. The interaction between PDLP7 and BG10 was found to depend on the presence of the Gnk2-homologous 1 (GnK2-1) domain at the N terminus of PDLP7 with Asp-35, Cys-42, Gln-44, and Leu-116 being essential. In vitro supplementation of callose was able to change the conformation of the GnK2-1 domain. Our data suggest that the GnK2-1 domain of PDLP7, in conjunction with callose and BG10, plays a key role in plasmodesmata opening and closure, which is necessary for intercellular movement of various molecules.
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Affiliation(s)
- Xin Chen
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Wan-Wan Li
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Jin Gao
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Zhiguo Wu
- Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Juan Du
- Chinese Academy of Sciences, Institute of Zoology, State Key Lab Integrated Management Pest Insects, Beijing 100101, China
| | - XiaoMing Zhang
- Chinese Academy of Sciences, Institute of Zoology, State Key Lab Integrated Management Pest Insects, Beijing 100101, China
| | - Yu-Xian Zhu
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China; Institute for Advanced Studies, Wuhan University, Wuhan 430072, China.
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6
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Brunkard JO. Communicating Across Cell Walls: Structure, Evolution, and Regulation of Plasmodesmatal Transport in Plants. Results Probl Cell Differ 2024; 73:73-86. [PMID: 39242375 DOI: 10.1007/978-3-031-62036-2_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2024]
Abstract
Plasmodesmata are conduits in plant cell walls that allow neighboring cells to communicate and exchange resources. Despite their central importance to plant development and physiology, our understanding of plasmodesmata is relatively limited compared to other subcellular structures. In recent years, technical advances in electron microscopy, mass spectrometry, and phylogenomics have illuminated the structure, composition, and evolution of plasmodesmata in diverse plant lineages. In parallel, forward genetic screens have revealed key signaling pathways that converge to regulate plasmodesmatal transport, including chloroplast-derived retrograde signaling, phytohormone signaling, and metabolic regulation by the conserved eukaryotic Target of Rapamycin kinase. This review summarizes our current knowledge of the structure, evolution, and regulation of plasmodesmatal transport in plants.
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Affiliation(s)
- Jacob O Brunkard
- Laboratory of Genetics, University of Wisconsin - Madison, Madison, WI, USA.
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7
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Christensen AH, Gupta A, Chen G, Peters WS, Knoblauch M, Stone HA, Jensen KH. Locally optimal geometry for surface-enhanced diffusion. Phys Rev E 2023; 108:045101. [PMID: 37978587 DOI: 10.1103/physreve.108.045101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 08/16/2023] [Indexed: 11/19/2023]
Abstract
Molecular diffusion in bulk liquids proceeds according to Fick's law, which stipulates that the particle current is proportional to the conductive area. This constrains the efficiency of filtration systems in which both selectivity and permeability are valued. Previous studies have demonstrated that interactions between the diffusing species and solid boundaries can enhance or reduce particle transport relative to bulk conditions. However, only cases that preserve the monotonic relationship between particle current and conductive area are known. In this paper, we expose a system in which the diffusive current increases when the conductive area diminishes. These examples are based on the century-old theory of a charged particle interacting with an electrical double layer. This surprising discovery could improve the efficiency of filtration and may advance our understanding of biological pore structures.
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Affiliation(s)
| | - Ankur Gupta
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, USA
| | - Guang Chen
- Department of Advanced Manufacturing and Robotics, College of Engineering, Peking University, Beijing 100871, People's Republic of China
| | - Winfried S Peters
- School of Biological Sciences, Washington State University, Pullman, Washington 99164, USA
| | - Michael Knoblauch
- School of Biological Sciences, Washington State University, Pullman, Washington 99164, USA
| | - Howard A Stone
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Kaare H Jensen
- Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
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8
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Barr ZK, Werner T, Tilsner J. Heavy Metal-Associated Isoprenylated Plant Proteins (HIPPs) at Plasmodesmata: Exploring the Link between Localization and Function. PLANTS (BASEL, SWITZERLAND) 2023; 12:3015. [PMID: 37631227 PMCID: PMC10459601 DOI: 10.3390/plants12163015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 08/09/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023]
Abstract
Heavy metal-associated isoprenylated plant proteins (HIPPs) are a metallochaperone-like protein family comprising a combination of structural features unique to vascular plants. HIPPs possess both one or two heavy metal-binding domains and an isoprenylation site, facilitating a posttranslational protein lipid modification. Recent work has characterized individual HIPPs across numerous different species and provided evidence for varied functionalities. Interestingly, a significant number of HIPPs have been identified in proteomes of plasmodesmata (PD)-nanochannels mediating symplastic connectivity within plant tissues that play pivotal roles in intercellular communication during plant development as well as responses to biotic and abiotic stress. As characterized functions of many HIPPs are linked to stress responses, plasmodesmal HIPP proteins are potentially interesting candidate components of signaling events at or for the regulation of PD. Here, we review what is known about PD-localized HIPP proteins specifically, and how the structure and function of HIPPs more generally could link to known properties and regulation of PD.
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Affiliation(s)
- Zoe Kathleen Barr
- Biomedical Sciences Research Complex, University of St Andrews, BMS Building, North Haugh, St Andrews, Fife KY16 9ST, UK;
- Cell & Molecular Sciences, The James Hutton Institute, Dundee DD2 5DA, UK
| | - Tomáš Werner
- Department of Biology, University of Graz, Schubertstraße 51, 8010 Graz, Austria
| | - Jens Tilsner
- Biomedical Sciences Research Complex, University of St Andrews, BMS Building, North Haugh, St Andrews, Fife KY16 9ST, UK;
- Cell & Molecular Sciences, The James Hutton Institute, Dundee DD2 5DA, UK
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9
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Heeney M, Frank MH. The mRNA mobileome: challenges and opportunities for deciphering signals from the noise. THE PLANT CELL 2023; 35:1817-1833. [PMID: 36881847 DOI: 10.1093/plcell/koad063] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 05/30/2023]
Abstract
Organismal communication entails encoding a message that is sent over space or time to a recipient cell, where that message is decoded to activate a downstream response. Defining what qualifies as a functional signal is essential for understanding intercellular communication. In this review, we delve into what is known and unknown in the field of long-distance messenger RNA (mRNA) movement and draw inspiration from the field of information theory to provide a perspective on what defines a functional signaling molecule. Although numerous studies support the long-distance movement of hundreds to thousands of mRNAs through the plant vascular system, only a small handful of these transcripts have been associated with signaling functions. Deciphering whether mobile mRNAs generally serve a role in plant communication has been challenging, due to our current lack of understanding regarding the factors that influence mRNA mobility. Further insight into unsolved questions regarding the nature of mobile mRNAs could provide an understanding of the signaling potential of these macromolecules.
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Affiliation(s)
- Michelle Heeney
- Plant Biology Section, School of Integrative Plant Science, Cornell University, 14853 Ithaca, NY, USA
| | - Margaret H Frank
- Plant Biology Section, School of Integrative Plant Science, Cornell University, 14853 Ithaca, NY, USA
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10
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Lu Y, Fricke W. Salt Stress-Regulation of Root Water Uptake in a Whole-Plant and Diurnal Context. Int J Mol Sci 2023; 24:ijms24098070. [PMID: 37175779 PMCID: PMC10179082 DOI: 10.3390/ijms24098070] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 04/25/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
This review focuses on the regulation of root water uptake in plants which are exposed to salt stress. Root water uptake is not considered in isolation but is viewed in the context of other potential tolerance mechanisms of plants-tolerance mechanisms which relate to water relations and gas exchange. Plants spend between one third and half of their lives in the dark, and salt stress does not stop with sunset, nor does it start with sunrise. Surprisingly, how plants deal with salt stress during the dark has received hardly any attention, yet any growth response to salt stress over days, weeks, months and years is the integrative result of how plants perform during numerous, consecutive day/night cycles. As we will show, dealing with salt stress during the night is a prerequisite to coping with salt stress during the day. We hope to highlight with this review not so much what we know, but what we do not know; and this relates often to some rather basic questions.
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Affiliation(s)
- Yingying Lu
- School of Biology and Environmental Science, University College Dublin (UCD), Belfield, D04 N2E5 Dublin, Ireland
| | - Wieland Fricke
- School of Biology and Environmental Science, University College Dublin (UCD), Belfield, D04 N2E5 Dublin, Ireland
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11
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Grünhofer P, Schreiber L. Cutinized and suberized barriers in leaves and roots: Similarities and differences. JOURNAL OF PLANT PHYSIOLOGY 2023; 282:153921. [PMID: 36780757 DOI: 10.1016/j.jplph.2023.153921] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 11/18/2022] [Accepted: 01/09/2023] [Indexed: 06/18/2023]
Abstract
Anatomical, histochemical, chemical, and biosynthetic similarities and differences of cutinized and suberized plant cell walls are presented and reviewed in brief. Based on this, the functional properties of cutinized and suberized plant cell walls acting as transport barriers are compared and discussed in more detail. This is of general importance because fundamental misconceptions about relationships in plant-environment water relations are commonly encountered in the scientific literature. It will be shown here, that cuticles represent highly efficient apoplastic transport barriers significantly reducing the diffusion of water and dissolved compounds. The transport barrier of cuticles is mainly established by the deposition of cuticular waxes. Upon wax extraction, with the cutin polymer remaining, cuticular permeability for water and dissolved non-ionized and lipophilic solutes are increasing by 2-3 orders of magnitude, whereas polar and charged substances (e.g., nutrient ions) are only weakly affected (2- to 3-fold increases in permeability). Suberized apoplastic barriers without the deposition of wax are at least as permeable as the cutin polymer matrix without waxes and hardly offer any resistance to the free movement of water. Only upon the deposition of significant amounts of wax, as it is the case with suberized periderms exposed to the atmosphere, an efficient transport barrier for water can be established by suberized cell walls. Comparing the driving forces (gradients between water potentials inside leaves and roots and the surrounding environment) for water loss acting on leaves and roots, it is shown that leaves must have a genetically pre-defined highly efficient transpiration barrier fairly independent from rapidly changing environmental influences. Roots, in most conditions facing a soil environment with relative humidities very close to 100%, are orders of magnitude more permeable to water than leaf cuticles. Upon desiccation, the permanent wilting point of plants is defined as -1.5 MPa, which still corresponds to nearly 99% relative humidity in soil. Thus, the main reason for plant water stress leading to dehydration is the inability of root tissues to decrease their internal water potential to values more negative than -1.5 MPa and not the lack of a transport barrier for water in roots and leaves. Taken together, the commonly mentioned concepts that a drought-induced increase of cuticular wax or root suberin considerably strengthens the apoplastic leaf or root transport barriers and thus aids in water conservation appears highly questionable.
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Affiliation(s)
- Paul Grünhofer
- Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115, Bonn, Germany.
| | - Lukas Schreiber
- Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115, Bonn, Germany.
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12
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Pavlicek A, Neubauer S, Zafiu C, Huber-Humer M, Ehmoser EK, Part F. The use and detection of quantum dots as nanotracers in environmental fate studies of engineered nanoparticles. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 317:120461. [PMID: 36272608 DOI: 10.1016/j.envpol.2022.120461] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 10/07/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
Investigations of the behavior and effects of engineered nanoparticles (ENPs) on human health and the environment need detailed knowledge of their fate and transport in environmental compartments. Such studies are highly challenging due to low environmental concentrations, varying size distribution of the particles and the interference with the natural background. A strategy to overcome these limits is to use mimics of ENPs with unique detectable properties that match the properties of the ENPs as nanotracers. A special class of ENPs that can be tracked are quantum dots (QDs). QDs are composed of different metals, metalloids, or more recently also carbon (e.g., graphene), that result in unique optical properties. This allows the tracking of such particles by fluorescence microscopic and photometric techniques. Many types of QDs consist of heavy elements, allowing to track and visualize these particles also by electron microscopy and to quantitate the particles indirectly based on these elements. QDs can also be surface modified in various ways which enable them to be used as a label or as traceable mimics for ENPs. This review reflects a broad range of methods to synthesize and modify QDs based on metals, metalloids, and graphene for studying the environmental fate of nanoparticles and discusses and compares analytical methods that can be used for tracking and quantifying QDs. In addition, we review applications of QDs as ENP mimics in environmental studies of surface waters, soils, microorganisms, and plants with respect to the applied analytical techniques.
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Affiliation(s)
- Anna Pavlicek
- University of Natural Resources and Life Sciences, Department of Nanobiotechnology, Institute for Synthetic Bioarchitectures, Muthgasse 11/II, 1190, Vienna, Austria
| | - Simon Neubauer
- University of Natural Resources and Life Sciences, Department of Water-Atmosphere-Environment, Institute of Waste Management and Circularity, Muthgasse 107, 1190, Vienna, Austria
| | - Christian Zafiu
- University of Natural Resources and Life Sciences, Department of Water-Atmosphere-Environment, Institute of Waste Management and Circularity, Muthgasse 107, 1190, Vienna, Austria.
| | - Marion Huber-Humer
- University of Natural Resources and Life Sciences, Department of Water-Atmosphere-Environment, Institute of Waste Management and Circularity, Muthgasse 107, 1190, Vienna, Austria
| | - Eva-Kathrin Ehmoser
- University of Natural Resources and Life Sciences, Department of Nanobiotechnology, Institute for Synthetic Bioarchitectures, Muthgasse 11/II, 1190, Vienna, Austria
| | - Florian Part
- University of Natural Resources and Life Sciences, Department of Water-Atmosphere-Environment, Institute of Waste Management and Circularity, Muthgasse 107, 1190, Vienna, Austria
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13
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Reinhardt D, Gola EM. Law and order in plants - the origin and functional relevance of phyllotaxis. TRENDS IN PLANT SCIENCE 2022; 27:1017-1032. [PMID: 35643801 DOI: 10.1016/j.tplants.2022.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 03/31/2022] [Accepted: 04/26/2022] [Indexed: 06/15/2023]
Abstract
The regular arrangement of organs (phyllotaxis) in vegetative shoots and flowers is one of the most stunning features of plants. Spiral patterns characterized by Fibonacci numbers have attracted the particular interest of natural scientists and mathematicians. Numerous reviews have dealt with the molecular genetic mechanisms underlying phyllotaxis, and modeling studies have sought to recreate phyllotaxis according to mathematical, biochemical, or physical laws. However, what is the functional significance of regular plant architecture, and how did it evolve? We discuss the developmental constraints and selective forces that may have favored the selection of phyllotaxis, and we argue that a central driver of regular phyllotaxis may have been limitations in the allocation of founder cells and metabolic resources to the different tissues in the shoot apex.
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Affiliation(s)
- Didier Reinhardt
- Department of Biology, Route Albert Gockel 3, University of Fribourg, 1700 Fribourg, Switzerland.
| | - Edyta M Gola
- Department of Plant Developmental Biology, Faculty of Plant Sciences, University of Wroclaw, Kanonia 6/8, 50-328, Wroclaw, Poland
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14
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Kitagawa M, Xu X, Jackson D. Trafficking and localization of KNOTTED1 related mRNAs in shoot meristems. Commun Integr Biol 2022; 15:158-163. [PMID: 35832536 PMCID: PMC9272838 DOI: 10.1080/19420889.2022.2095125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/24/2022] [Accepted: 06/24/2022] [Indexed: 11/10/2022] Open
Abstract
Multicellular organisms use transcripts and proteins as signaling molecules for cell-to-cell communication. Maize KNOTTED1 (KN1) was the first homeodomain transcription factor identified in plants, and functions in maintaining shoot stem cells. KN1 acts non-cell autonomously, and both its messenger RNA (mRNA) and protein traffic between cells through intercellular nanochannels called plasmodesmata. KN1 protein and mRNA trafficking are regulated by a chaperonin subunit and a catalytic subunit of the RNA exosome, respectively. These studies suggest that the function of KN1 in stem cell regulation requires the cell-to-cell transport of both its protein and mRNA. However, in situ hybridization experiments published 25 years ago suggested that KN1 mRNA was missing from the epidermal (L1) layer of shoot meristems, suggesting that only the KN1 protein could traffic. Here, we show evidence that KN1 mRNA is present at a low level in L1 cells of maize meristems, supporting an idea that both KN1 protein and mRNA traffic to the L1 layer. We also summarize mRNA expression patterns of KN1 homologs in diverse angiosperm species, and discuss KN1 trafficking mechanisms.
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Affiliation(s)
| | - Xiaosa Xu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - David Jackson
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
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15
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Ostermeyer GP, Jensen KH, Franzen AR, Peters WS, Knoblauch M. Diversity of funnel plasmodesmata in angiosperms: the impact of geometry on plasmodesmal resistance. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 110:707-719. [PMID: 35124855 DOI: 10.1111/tpj.15697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/30/2021] [Accepted: 01/25/2022] [Indexed: 06/14/2023]
Abstract
In most plant tissues, threads of cytoplasm, or plasmodesmata, connect the protoplasts via pores in the cell walls. This enables symplasmic transport, for instance in phloem loading, transport and unloading. Importantly, the geometry of the wall pore limits the size of the particles that may be transported, and also (co-)defines plasmodesmal resistance to diffusion and convective flow. However, quantitative information on transport through plasmodesmata in non-cylindrical cell wall pores is scarce. We have found conical, funnel-shaped cell wall pores in the phloem-unloading zone in growing root tips of five eudicot and two monocot species, specifically between protophloem sieve elements and phloem pole pericycle cells. 3D reconstructions by electron tomography suggested that funnel plasmodesmata possess a desmotubule but lack tethers to fix it in a central position. Model calculations showed that both diffusive and hydraulic resistance decrease drastically in conical and trumpet-shaped cell wall pores compared with cylindrical channels, even at very small opening angles. Notably, the effect on hydraulic resistance was relatively larger. We conclude that funnel plasmodesmata generally are present in specific cell-cell interfaces in angiosperm roots, where they appear to facilitate symplasmic phloem unloading. Interestingly, cytosolic sleeves of most plasmodesmata reported in the literature do not resemble annuli of constant diameter but possess variously shaped widenings. Our evaluations suggest that widenings too small for unambiguous identification on electron micrographs may drastically reduce the hydraulic and diffusional resistance of these pores. Consequently, theoretical models assuming cylindrical symmetries will underestimate plasmodesmal conductivities.
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Affiliation(s)
- Grayson P Ostermeyer
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Kaare H Jensen
- Department of Physics, Technical University of Denmark, DK-2800 Kgs, Lyngby, Denmark
| | - Aslak R Franzen
- Department of Physics, Technical University of Denmark, DK-2800 Kgs, Lyngby, Denmark
| | - 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
| | - Michael Knoblauch
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
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16
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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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17
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Tomkins M, Hughes A, Morris RJ. An update on passive transport in and out of plant cells. PLANT PHYSIOLOGY 2021; 187:1973-1984. [PMID: 35235675 PMCID: PMC8644452 DOI: 10.1093/plphys/kiab406] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 07/30/2021] [Indexed: 05/09/2023]
Abstract
Transport across membranes is critical for plant survival. Membranes are the interfaces at which plants interact with their environment. The transmission of energy and molecules into cells provides plants with the source material and power to grow, develop, defend, and move. An appreciation of the physical forces that drive transport processes is thus important for understanding the plant growth and development. We focus on the passive transport of molecules, describing the fundamental concepts and demonstrating how different levels of abstraction can lead to different interpretations of the driving forces. We summarize recent developments on quantitative frameworks for describing diffusive and bulk flow transport processes in and out of cells, with a more detailed focus on plasmodesmata, and outline open questions and challenges.
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Affiliation(s)
- Melissa Tomkins
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, NR4 7UH Norwich, UK
| | - Aoife Hughes
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, NR4 7UH Norwich, UK
| | - Richard J Morris
- Computational and Systems Biology, John Innes Centre, Norwich Research Park, NR4 7UH Norwich, UK
- Author for communication:
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18
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McCubbin TJ, Braun DM. Phloem anatomy and function as shaped by the cell wall. JOURNAL OF PLANT PHYSIOLOGY 2021; 266:153526. [PMID: 34555540 DOI: 10.1016/j.jplph.2021.153526] [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: 06/30/2021] [Revised: 09/12/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
The partitioning of assimilated carbon is a complex process that involves the loading, long-distance transport, and subsequent unloading of carbohydrates from source to sink tissues. The network of plumbing that facilitates this coordinated process is the phloem tissue. Our understanding of the physiology of phloem transport has grown tremendously since the modern theory of mass flow was first put forward, aided by the concomitant progress of technology and experimental methodologies. Recent findings have put a renewed emphasis on the underlying anatomy of the phloem, and in particular the important role that cell walls play in enabling the high-pressure flow of photoassimilates through the sieve element. This review will briefly summarize the foundational work in phloem anatomy and highlight recent work exploring the physiology of phloem cell wall structure and mechanics.
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Affiliation(s)
- Tyler J McCubbin
- Division of Plant Science and Technology, Interdisciplinary Plant Group, The Missouri Maize Center, University of Missouri,Columbia, MO, 65211, USA
| | - David M Braun
- Division of Plant Science and Technology, Interdisciplinary Plant Group, The Missouri Maize Center, University of Missouri,Columbia, MO, 65211, USA; Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA.
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19
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Robinson DG, Draguhn A. Plants have neither synapses nor a nervous system. JOURNAL OF PLANT PHYSIOLOGY 2021; 263:153467. [PMID: 34247030 DOI: 10.1016/j.jplph.2021.153467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/16/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
The alleged existence of so-called synapses or equivalent structures in plants provided the basis for the concept of Plant Neurobiology (Baluska et al., 2005; Brenner et al., 2006). More recently, supporters of this controversial theory have even speculated that the phloem acts as a kind of nerve system serving long distance electrical signaling (Mediano et al., 2021; Baluska and Mancuso, 2021). In this review we have critically examined the literature cited by these authors and arrive at a completely different conclusion. Plants do not have any structures resembling animal synapses (neither chemical nor electrical). While they certainly do have complex cell contacts and signaling mechanisms, none of these structures provides a basis for neuronal-like synaptic transmission. Likewise, the phloem is undoubtedly a conduit for the propagation of electrical signaling, but the characteristics of this process are in no way comparable to the events underlying information processing in neuronal networks. This has obvious implications in regard to far-going speculations into the realms of cognition, sentience and consciousness.
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Affiliation(s)
- David G Robinson
- Centre for Organismal Studies, University of Heidelberg, 69120, Heidelberg, Germany.
| | - Andreas Draguhn
- Institute for Physiology and Pathophysiology, Medical Faculty, University of Heidelberg, 69120, Heidelberg, Germany
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20
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Liu J, Zhang L, Yan D. Plasmodesmata-Involved Battle Against Pathogens and Potential Strategies for Strengthening Hosts. FRONTIERS IN PLANT SCIENCE 2021; 12:644870. [PMID: 34149749 PMCID: PMC8210831 DOI: 10.3389/fpls.2021.644870] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 04/28/2021] [Indexed: 06/01/2023]
Abstract
Plasmodesmata (PD) are membrane-lined pores that connect adjacent cells to mediate symplastic communication in plants. These intercellular channels enable cell-to-cell trafficking of various molecules essential for plant development and stress responses, but they can also be utilized by pathogens to facilitate their infection of hosts. Some pathogens or their effectors are able to spread through the PD by modifying their permeability. Yet plants have developed various corresponding defense mechanisms, including the regulation of PD to impede the spread of invading pathogens. In this review, we aim to illuminate the various roles of PD in the interactions between pathogens and plants during the infection process. We summarize the pathogenic infections involving PD and how the PD could be modified by pathogens or hosts. Furthermore, we propose several hypothesized and promising strategies for enhancing the disease resistance of host plants by the appropriate modulation of callose deposition and plasmodesmal permeability based on current knowledge.
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Affiliation(s)
- Jie Liu
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Lin Zhang
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou, China
| | - Dawei Yan
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
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21
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Mai MH, Holbrook NM. A tale to astonish: Ant-Man at the plasmodesmal gates. JOURNAL OF PLANT PHYSIOLOGY 2021; 261:153431. [PMID: 33964797 DOI: 10.1016/j.jplph.2021.153431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
- Melissa H Mai
- Harvard Biophysics Program, Harvard University, United States
| | - N Michele Holbrook
- Department of Organismic and Evolutionary Biology, Harvard University, United States.
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