1
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Yan H, Mendieta JP, Zhang X, Marand AP, Liang Y, Luo Z, Minow MAA, Roulé T, Wagner D, Tu X, Wang Y, Zhong S, Wessler SR, Schmitz RJ. Evolution of plant cell-type-specific cis -regulatory elements. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.08.574753. [PMID: 38260561 PMCID: PMC10802394 DOI: 10.1101/2024.01.08.574753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Cis -regulatory elements (CREs) are critical in regulating gene expression, and yet our understanding of CRE evolution remains a challenge. Here, we constructed a comprehensive single-cell atlas of chromatin accessibility in Oryza sativa , integrating data from 104,029 nuclei representing 128 discrete cell states across nine distinct organs. We used comparative genomics to compare cell-type resolved chromatin accessibility between O. sativa and 57,552 nuclei from four additional grass species ( Zea mays, Sorghum bicolor, Panicum miliaceum , and Urochloa fusca ). Accessible chromatin regions (ACRs) had different levels of conservation depending on the degree of cell-type specificity. We found a complex relationship between ACRs with conserved noncoding sequences, cell-type specificity, conservation, and tissue-specific switching. Additionally, we found that epidermal ACRs were less conserved compared to other cell types, potentially indicating that more rapid regulatory evolution has occurred in the L1 epidermal layer of these species. Finally, we identified and characterized a conserved subset of ACRs that overlapped the repressive histone modification H3K27me3, implicating them as potentially critical silencer CREs maintained by evolution. Collectively, this comparative genomics approach highlights the dynamics of cell-type-specific CRE evolution in plants.
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2
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Matilla AJ. The Interplay between Enucleated Sieve Elements and Companion Cells. PLANTS (BASEL, SWITZERLAND) 2023; 12:3033. [PMID: 37687278 PMCID: PMC10489895 DOI: 10.3390/plants12173033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/10/2023] [Accepted: 08/15/2023] [Indexed: 09/10/2023]
Abstract
In order to adapt to sessile life and terrestrial environments, vascular plants have developed highly sophisticated cells to transport photosynthetic products and developmental signals. Of these, two distinct cell types (i.e., the sieve element (SE) and companion cell) are arranged in precise positions, thus ensuring effective transport. During SE differentiation, most of the cellular components are heavily modified or even eliminated. This peculiar differentiation implies the selective disintegration of the nucleus (i.e., enucleation) and the loss of cellular translational capacity. However, some cellular components necessary for transport (e.g., plasmalemma) are retained and specific phloem proteins (P-proteins) appear. Likewise, MYB (i.e., APL) and NAC (i.e., NAC45 and NAC86) transcription factors (TFs) and OCTOPUS proteins play a notable role in SE differentiation. The maturing SEs become heavily dependent on neighboring non-conducting companion cells, to which they are connected by plasmodesmata through which only 20-70 kDa compounds seem to be able to pass. The study of sieve tube proteins still has many gaps. However, the development of a protocol to isolate proteins that are free from any contaminating proteins has constituted an important advance. This review considers the very detailed current state of knowledge of both bound and soluble sap proteins, as well as the role played by the companion cells in their presence. Phloem proteins travel long distances by combining two modes: non-selective transport via bulk flow and selective regulated movement. One of the goals of this study is to discover how the protein content of the sieve tube is controlled. The majority of questions and approaches about the heterogeneity of phloem sap will be clarified once the morphology and physiology of the plasmodesmata have been investigated in depth. Finally, the retention of specific proteins inside an SE is an aspect that should not be forgotten.
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Affiliation(s)
- Angel J Matilla
- Departamento de Biología Funcional, Universidad de Santiago de Compostela, 14971-Santiago de Compostela, Spain
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3
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Sun S, Shen X, Li Y, Li Y, Wang S, Li R, Zhang H, Shen G, Guo B, Wei J, Xu J, St-Pierre B, Chen S, Sun C. Single-cell RNA sequencing provides a high-resolution roadmap for understanding the multicellular compartmentation of specialized metabolism. NATURE PLANTS 2023; 9:179-190. [PMID: 36522449 DOI: 10.1038/s41477-022-01291-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 10/26/2022] [Indexed: 06/17/2023]
Abstract
Monoterpenoid indole alkaloids (MIAs) are among the most diverse specialized metabolites in plants and are of great pharmaceutical importance. We leveraged single-cell transcriptomics to explore the spatial organization of MIA metabolism in Catharanthus roseus leaves, and the transcripts of 20 MIA genes were first localized, updating the model of MIA biosynthesis. The MIA pathway was partitioned into three cell types, consistent with the results from RNA in situ hybridization experiments. Several candidate transporters were predicted to be essential players shuttling MIA intermediates between inter- and intracellular compartments, supplying potential targets to increase the overall yields of desirable MIAs in native plants or heterologous hosts through metabolic engineering and synthetic biology. This work provides not only a universal roadmap for elucidating the spatiotemporal distribution of biological processes at single-cell resolution, but also abundant cellular and genetic resources for further investigation of the higher-order organization of MIA biosynthesis, transport and storage.
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Affiliation(s)
- Sijie Sun
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiaofeng Shen
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yi Li
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ying Li
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shu Wang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Rucan Li
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Huibo Zhang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Guoan Shen
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Baolin Guo
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jianhe Wei
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jiang Xu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Benoit St-Pierre
- EA2106 Biomolécules et Biotechnologies Végétales, Université de Tours, Tours, France.
| | - Shilin Chen
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China.
- Chengdu University of Traditional Chinese Medicine, Chengdu, China.
| | - Chao Sun
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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4
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van Bel AJE, Schulz A, Patrick JW. New mosaic fragments toward reconstructing the elusive phloem system. JOURNAL OF PLANT PHYSIOLOGY 2022; 275:153754. [PMID: 35753158 DOI: 10.1016/j.jplph.2022.153754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Affiliation(s)
- Aart J E van Bel
- Institut of Phytopathology, Centre for Biosystems, Land Use and Nutrition, Justus-Liebig University, Heinrich-Buff-Ring 26-32, D-35392 Gieβen, Germany.
| | - Alexander Schulz
- Department of Plant and Environmental Sciences, Thorvaldsensvej 40, 1871 Frederiksberg, Copenhagen, Denmark
| | - John W Patrick
- Centre for Plant Science, School of Environmental and Life Sciences, The University of Newcastle, Callaghan NSW 2308, Australia
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5
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Otero S, Gildea I, Roszak P, Lu Y, Di Vittori V, Bourdon M, Kalmbach L, Blob B, Heo JO, Peruzzo F, Laux T, Fernie AR, Tavares H, Helariutta Y. A root phloem pole cell atlas reveals common transcriptional states in protophloem-adjacent cells. NATURE PLANTS 2022; 8:954-970. [PMID: 35927456 DOI: 10.1038/s41477-022-01178-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
Single-cell sequencing has recently allowed the generation of exhaustive root cell atlases. However, some cell types are elusive and remain underrepresented. Here we use a second-generation single-cell approach, where we zoom in on the root transcriptome sorting with specific markers to profile the phloem poles at an unprecedented resolution. Our data highlight the similarities among the developmental trajectories and gene regulatory networks common to protophloem sieve element (PSE)-adjacent lineages in relation to PSE enucleation, a key event in phloem biology. As a signature for early PSE-adjacent lineages, we have identified a set of DNA-binding with one finger (DOF) transcription factors, the PINEAPPLEs (PAPL), that act downstream of PHLOEM EARLY DOF (PEAR) genes and are important to guarantee a proper root nutrition in the transition to autotrophy. Our data provide a holistic view of the phloem poles that act as a functional unit in root development.
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Affiliation(s)
- Sofia Otero
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK
| | - Iris Gildea
- Institute of Biotechnology, HiLIFE/Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
- Department of Plant Biology and Genome Center, University of California, Davis, CA, USA
| | - Pawel Roszak
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK
| | - Yipeng Lu
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK
| | - Valerio Di Vittori
- Max-Planck-Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
- Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università Politecnica delle Marche, Ancona, Italy
| | - Matthieu Bourdon
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK
| | - Lothar Kalmbach
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK
| | - Bernhard Blob
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK
| | - Jung-Ok Heo
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK
| | | | - Thomas Laux
- Signalling Research Centres BIOSS and CIBSS, Freiburg, Germany
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Hugo Tavares
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK.
- Department of Genetics, University of Cambridge, Cambridge, UK.
| | - Yka Helariutta
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK.
- Institute of Biotechnology, HiLIFE/Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.
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6
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Tenorio Berrío R, Verstaen K, Vandamme N, Pevernagie J, Achon I, Van Duyse J, Van Isterdael G, Saeys Y, De Veylder L, Inzé D, Dubois M. Single-cell transcriptomics sheds light on the identity and metabolism of developing leaf cells. PLANT PHYSIOLOGY 2022; 188:898-918. [PMID: 34687312 PMCID: PMC8825278 DOI: 10.1093/plphys/kiab489] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 10/05/2021] [Indexed: 05/08/2023]
Abstract
As the main photosynthetic instruments of vascular plants, leaves are crucial and complex plant organs. A strict organization of leaf mesophyll and epidermal cell layers orchestrates photosynthesis and gas exchange. In addition, water and nutrients for leaf growth are transported through the vascular tissue. To establish the single-cell transcriptomic landscape of these different leaf tissues, we performed high-throughput transcriptome sequencing of individual cells isolated from young leaves of Arabidopsis (Arabidopsis thaliana) seedlings grown in two different environmental conditions. The detection of approximately 19,000 different transcripts in over 1,800 high-quality leaf cells revealed 14 cell populations composing the young, differentiating leaf. Besides the cell populations comprising the core leaf tissues, we identified subpopulations with a distinct identity or metabolic activity. In addition, we proposed cell-type-specific markers for each of these populations. Finally, an intuitive web tool allows for browsing the presented dataset. Our data present insights on how the different cell populations constituting a developing leaf are connected via developmental, metabolic, or stress-related trajectories.
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Affiliation(s)
- Rubén Tenorio Berrío
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Kevin Verstaen
- Department of Applied Mathematics, Ghent University, Computer Science and Statistics, Ghent, Belgium
- VIB Center for Inflammation Research, Ghent, Belgium
| | - Niels Vandamme
- Department of Applied Mathematics, Ghent University, Computer Science and Statistics, Ghent, Belgium
- VIB Center for Inflammation Research, Ghent, Belgium
| | - Julie Pevernagie
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Ignacio Achon
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Julie Van Duyse
- VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Gert Van Isterdael
- VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Yvan Saeys
- Department of Applied Mathematics, Ghent University, Computer Science and Statistics, Ghent, Belgium
- VIB Center for Inflammation Research, Ghent, Belgium
| | - Lieven De Veylder
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Dirk Inzé
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
- Author for communication:
| | - Marieke Dubois
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
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7
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Ma W, Pang Z, Huang X, Xu J, Pandey SS, Li J, Achor DS, Vasconcelos FNC, Hendrich C, Huang Y, Wang W, Lee D, Stanton D, Wang N. Citrus Huanglongbing is a pathogen-triggered immune disease that can be mitigated with antioxidants and gibberellin. Nat Commun 2022; 13:529. [PMID: 35082290 PMCID: PMC8791970 DOI: 10.1038/s41467-022-28189-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/04/2022] [Indexed: 12/17/2022] Open
Abstract
Huanglongbing (HLB) is a devastating disease of citrus, caused by the phloem-colonizing bacterium Candidatus Liberibacter asiaticus (CLas). Here, we present evidence that HLB is an immune-mediated disease. We show that CLas infection of Citrus sinensis stimulates systemic and chronic immune responses in phloem tissue, including callose deposition, production of reactive oxygen species (ROS) such as H2O2, and induction of immunity-related genes. The infection also upregulates genes encoding ROS-producing NADPH oxidases, and downregulates antioxidant enzyme genes, supporting that CLas causes oxidative stress. CLas-triggered ROS production localizes in phloem-enriched bark tissue and is followed by systemic cell death of companion and sieve element cells. Inhibition of ROS levels in CLas-positive stems by NADPH oxidase inhibitor diphenyleneiodonium (DPI) indicates that NADPH oxidases contribute to CLas-triggered ROS production. To investigate potential treatments, we show that addition of the growth hormone gibberellin (known to have immunoregulatory activities) upregulates genes encoding H2O2-scavenging enzymes and downregulates NADPH oxidases. Furthermore, foliar spray of HLB-affected citrus with gibberellin or antioxidants (uric acid, rutin) reduces H2O2 concentrations and cell death in phloem tissues and reduces HLB symptoms. Thus, our results indicate that HLB is an immune-mediated disease that can be mitigated with antioxidants and gibberellin.
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Affiliation(s)
- Wenxiu Ma
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Zhiqian Pang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Xiaoen Huang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Jin Xu
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Sheo Shankar Pandey
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Jinyun Li
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Diann S Achor
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Fernanda N C Vasconcelos
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Connor Hendrich
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Yixiao Huang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Wenting Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Donghwan Lee
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Daniel Stanton
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, IFAS, University of Florida, Lake Alfred, FL, USA.
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8
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Mishra BS, Sharma M, Laxmi A. Role of sugar and auxin crosstalk in plant growth and development. PHYSIOLOGIA PLANTARUM 2022; 174:e13546. [PMID: 34480799 DOI: 10.1111/ppl.13546] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 05/07/2023]
Abstract
Under the natural environment, nutrient signals interact with phytohormones to coordinate and reprogram plant growth and survival. Sugars are important molecules that control almost all morphological and physiological processes in plants, ranging from seed germination to senescence. In addition to their functions as energy resources, osmoregulation, storage molecules, and structural components, sugars function as signaling molecules and interact with various plant signaling pathways, such as hormones, stress, and light to modulate growth and development according to fluctuating environmental conditions. Auxin, being an important phytohormone, is associated with almost all stages of the plant's life cycle and also plays a vital role in response to the dynamic environment for better growth and survival. In the previous years, substantial progress has been made that showed a range of common responses mediated by sugars and auxin signaling. This review discusses how sugar signaling affects auxin at various levels from its biosynthesis to perception and downstream gene activation. On the same note, the review also highlights the role of auxin signaling in fine-tuning sugar metabolism and carbon partitioning. Furthermore, we discussed the crosstalk between the two signaling machineries in the regulation of various biological processes, such as gene expression, cell cycle, development, root system architecture, and shoot growth. In conclusion, the review emphasized the role of sugar and auxin crosstalk in the regulation of several agriculturally important traits. Thus, engineering of sugar and auxin signaling pathways could potentially provide new avenues to manipulate for agricultural purposes.
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Affiliation(s)
- Bhuwaneshwar Sharan Mishra
- National Institute of Plant Genome Research, New Delhi, India
- Bhuwaneshwar Sharan Mishra, Ram Gulam Rai P. G. College Banktashiv, Affiliated to Deen Dayal Upadhyaya Gorakhpur University Gorakhpur, Deoria, Uttar Pradesh, India
| | - Mohan Sharma
- National Institute of Plant Genome Research, New Delhi, India
| | - Ashverya Laxmi
- National Institute of Plant Genome Research, New Delhi, India
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9
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Truernit E. Sieve elements and their cell neighbours in the Arabidopsis root - Roles and relationships. JOURNAL OF PLANT PHYSIOLOGY 2022; 268:153569. [PMID: 34801777 DOI: 10.1016/j.jplph.2021.153569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/06/2021] [Accepted: 11/11/2021] [Indexed: 06/13/2023]
Affiliation(s)
- Elisabeth Truernit
- ETH Zürich, Institute of Molecular Plant Biology, Department of Biology, Universitätsstrasse 2, 8092 Zürich, Switzerland.
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10
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van Bel AJE. The plant axis as the command centre for (re)distribution of sucrose and amino acids. JOURNAL OF PLANT PHYSIOLOGY 2021; 265:153488. [PMID: 34416599 DOI: 10.1016/j.jplph.2021.153488] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 07/13/2021] [Accepted: 08/01/2021] [Indexed: 06/13/2023]
Abstract
Along with the increase in size required for optimal colonization of terrestrial niches, channels for bidirectional bulk transport of materials in land plants evolved during a period of about 100 million years. These transport systems are essentially still in operation - though perfected over the following 400 million years - and make use of hydrostatic differentials. Substances are accumulated or released at the loading and unloading ends, respectively, of the transport channels. The intermediate stretch between the channel termini is bifunctional and executes orchestrated release and retrieval of solutes. Analyses of anatomical and physiological data demonstrate that the release/retrieval zone extends deeper into sources and sinks than is commonly thought and covers usually much more than 99% of the translocation stretch. This review sketches the significance of events in the intermediate stretch for distribution of organic materials over the plant body. Net leakage from the channels does not only serve maintenance and growth of tissues along the pathway, but also diurnal, short-term or seasonal storage of reserve materials, and balanced distribution of organic C- and N-compounds over axial and terminal sinks. Release and retrieval are controlled by plasma-membrane transporters at the vessel/parenchyma interface in the contact pits along xylem vessels and by plasma-membrane transporters at the interface between companion cells and phloem parenchyma along sieve tubes. The xylem-to-phloem pathway vice versa is a bifacial, radially oriented system comprising a symplasmic pathway, of which entrance and exit are controlled at specific membrane checkpoints, and a parallel apoplasmic pathway. A broad range of specific sucrose and amino-acid transporters are deployed at the checkpoint plasma membranes. SUCs, SUTs, STPs, SWEETs, and AAPs, LTHs, CATs are localized to the plasma membranes in question, both in monocots and eudicots. Presence of Umamits in monocots is uncertain. There is some evidence for endo- and exocytosis at the vessel/parenchyma interface supplementary to the transporter-mediated uptake and release. Actions of transporters at the checkpoints are equally decisive for storage and distribution of amino acids and sucrose in monocots and eudicots, but storage and distribution patterns may differ between both taxa. While the majority of reserves is sequestered in vascular parenchyma cells in dicots, lack of space in monocot vasculature urges "outsourcing" of storage in ground parenchyma around the translocation path. In perennial dicots, specialized radial pathways (rays) include the sites for seasonal alternation of storage and mobilization. In dicots, apoplasmic phloem loading and a correlated low rate of release along the path would favour supply with photoassimilates of terminal sinks, while symplasmic phloem loading and a correlated higher rate of release along the path favours supply of axial sinks and transfer to the xylem. The balance between the resource acquisition by terminal and axial sinks is an important determinant of relative growth rate and, hence, for the fitness of plants in various habitats. Body enlargement as the evolutionary drive for emergence of vascular systems and mass transport propelled by hydrostatic differentials.
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Affiliation(s)
- Aart J E van Bel
- Institute of Phythopathology, Centre for BioSystems, Land Use and Nutrition, Justus-Liebig University, Heinrich-Buff-Ring 26-32, D-35392, Giessen, Germany.
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11
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Krausko M, Labajová M, Peterková D, Jásik J. Specific expression of AtIRT1 in phloem companion cells suggests its role in iron translocation in aboveground plant organs. PLANT SIGNALING & BEHAVIOR 2021; 16:1925020. [PMID: 34057037 PMCID: PMC8281124 DOI: 10.1080/15592324.2021.1925020] [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: 03/24/2021] [Accepted: 03/28/2021] [Indexed: 06/12/2023]
Abstract
IRON-REGULATED TRANSPORTER 1 (IRT1) is a central iron transporter responsible for the uptake of iron from the rhizosphere to root epidermal cells. This study uses immunohistochemistry, histochemistry, and fluorometry to show that this gene's promoter is also active in the aboveground parts, specifically in phloem companied cells. Promoter activity here was regulated by iron as it was in the roots. The promoter of the close IRT2 homolog was root-specific and only weakly active in the stem pits. RT-PCR showed the presence of a long splicing form exclusively in iron-deficient roots. The short splicing form was present in all organs regardless of the presence of iron. Immunohistology exhibited labeling on the periphery of the epidermal cells in matured root zone and intracellular patches in the meristematic cells. In the aboveground organs, the protein was seen in the whole volume of companion cells and in neighboring sieve elements as bodies. The fluorescent protein technique revealed the short IRT1 form to be present in the patches accumulated mainly around the nucleus and the long form as a continuous layer along the cells periphery. These results suggest that IRT1 has a role also in the aboveground organs.
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Affiliation(s)
- Miroslav Krausko
- Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Bratislava 4, Slovak Republic
| | - Mária Labajová
- Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Bratislava 4, Slovak Republic
| | - Darina Peterková
- Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Bratislava 4, Slovak Republic
| | - Ján Jásik
- Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Bratislava 4, Slovak Republic
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12
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Paulmann MK, Zimmermann MR, Wegner L, van Bel AJE, Kunert G, Furch ACU. Species-Specific and Distance-Dependent Dispersive Behaviour of Forisomes in Different Legume Species. Int J Mol Sci 2021; 22:E492. [PMID: 33419062 PMCID: PMC7825422 DOI: 10.3390/ijms22020492] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 12/30/2020] [Accepted: 01/02/2021] [Indexed: 01/12/2023] Open
Abstract
Forisomes are giant fusiform protein complexes composed of sieve element occlusion (SEO) protein monomers, exclusively found in sieve elements (SEs) of legumes. Forisomes block the phloem mass flow by a Ca2+-induced conformational change (swelling and rounding). We studied the forisome reactivity in four different legume species-Medicago sativa, Pisum sativum, Trifolium pratense and Vicia faba. Depending on the species, we found direct relationships between SE diameter, forisome surface area and distance from the leaf tip, all indicative of a developmentally tuned regulation of SE diameter and forisome size. Heat-induced forisome dispersion occurred later with increasing distance from the stimulus site. T. pratense and V. faba dispersion occurred faster for forisomes with a smaller surface area. Near the stimulus site, electro potential waves (EPWs)-overlapping action (APs), and variation potentials (VPs)-were linked with high full-dispersion rates of forisomes. Distance-associated reduction of forisome reactivity was assigned to the disintegration of EPWs into APs, VPs and system potentials (SPs). Overall, APs and SPs alone were unable to induce forisome dispersion and only VPs above a critical threshold were capable of inducing forisome reactions.
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Affiliation(s)
- Maria K. Paulmann
- Plant Physiology, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Faculty of Biological Science, Friedrich Schiller University Jena, Dornburger Straße 159, 07743 Jena, Germany; (M.K.P.); (M.R.Z.); (L.W.)
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745 Jena, Germany;
| | - Matthias R. Zimmermann
- Plant Physiology, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Faculty of Biological Science, Friedrich Schiller University Jena, Dornburger Straße 159, 07743 Jena, Germany; (M.K.P.); (M.R.Z.); (L.W.)
| | - Linus Wegner
- Plant Physiology, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Faculty of Biological Science, Friedrich Schiller University Jena, Dornburger Straße 159, 07743 Jena, Germany; (M.K.P.); (M.R.Z.); (L.W.)
| | - Aart J. E. van Bel
- Interdisciplinary Research Centre, Institute of Phytopathology, Justus Liebig University, Heinrich-Buff-Ring 26, 35392 Giessen, Germany;
| | - Grit Kunert
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745 Jena, Germany;
| | - Alexandra C. U. Furch
- Plant Physiology, Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Faculty of Biological Science, Friedrich Schiller University Jena, Dornburger Straße 159, 07743 Jena, Germany; (M.K.P.); (M.R.Z.); (L.W.)
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13
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Seo M, Kim H, Lee JY. Information on the move: vascular tissue development in space and time during postembryonic root growth. CURRENT OPINION IN PLANT BIOLOGY 2020; 57:110-117. [PMID: 32905917 DOI: 10.1016/j.pbi.2020.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 07/08/2020] [Accepted: 08/04/2020] [Indexed: 05/27/2023]
Abstract
Cascades of temporal and spatial regulation of gene expression play crucial roles in the vascular development in plant roots. Once vascular cell fates are determined, the timing of their differentiation is tightly controlled in a cell-autonomous manner. In contrast, extensive cell-to-cell communication contributes to the positioning and specifying of vascular cell types in the root meristem. Diverse factors moving short distances in a radial direction were found to be key contributors to these processes. Furthermore, signals from differentiated phloem were found to influence the phloem precursor and determine how the corresponding asymmetric cell division proceeded. These findings highlight the potential importance of underexplored types of intercellular communication in relation to vascular tissue development during postembryonic root growth.
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Affiliation(s)
- Minji Seo
- School of Biological Sciences, College of Natural Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyoujin Kim
- School of Biological Sciences, College of Natural Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Ji-Young Lee
- School of Biological Sciences, College of Natural Science, Seoul National University, Seoul 08826, Republic of Korea; Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Republic of Korea.
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14
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Bagdassarian KS, Brown CM, Jones ET, Etchells P. Connections in the cambium, receptors in the ring. CURRENT OPINION IN PLANT BIOLOGY 2020; 57:96-103. [PMID: 32866742 DOI: 10.1016/j.pbi.2020.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 07/05/2020] [Accepted: 07/22/2020] [Indexed: 05/04/2023]
Abstract
In plants, pluripotent cells in meristems divide to provide cells for the formation of postembryonic tissues. The cambium is the meristem from which the vascular tissue is derived and is the main driver for secondary (radial) growth in dicots. Xylem and phloem are specified on opposing sides of the cambium, and tightly regulated cell divisions ensure their spatial separation. Peptide ligands, phytohormones, and their receptors are central to maintaining this patterning and regulating proliferation. Here, we describe recent advances in our understanding of how these signals are integrated to control vascular development and secondary growth.
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Affiliation(s)
| | - Catherine M Brown
- Department of Biosciences, Durham University, Durham, DH1 3LE, United Kingdom
| | - Ewan T Jones
- Department of Biosciences, Durham University, Durham, DH1 3LE, United Kingdom
| | - Peter Etchells
- Department of Biosciences, Durham University, Durham, DH1 3LE, United Kingdom.
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15
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Champeyroux C, Stoof C, Rodriguez-Villalon A. Signaling phospholipids in plant development: small couriers determining cell fate. CURRENT OPINION IN PLANT BIOLOGY 2020; 57:61-71. [PMID: 32771964 DOI: 10.1016/j.pbi.2020.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/24/2020] [Accepted: 05/23/2020] [Indexed: 05/25/2023]
Abstract
The survival of plants hinges on their ability to perceive various environmental stimuli and translate them into appropriate biochemical responses. Phospholipids, a class of membrane lipid compounds that are asymmetrically distributed within plant cells, stand out among signal transmitters for their diversity of mechanisms by which they modulate stress and developmental processes. By modifying the chemo-physical properties of the plasma membrane (PM) as well as vesicle trafficking, phospholipids contribute to changes in the protein membrane landscape, and hence, signaling responses. In this article, we review the distinct signaling mechanisms phospholipids are involved in, with a special focus on the nuclear role of these compounds. Additionally, we summarize exemplary developmental processes greatly influenced by phospholipids.
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Affiliation(s)
- Chloe Champeyroux
- Group of Plant Vascular Development, Swiss Federal Institute of Technology (ETH) Zurich, 8092 Zurich, Switzerland
| | - Claudia Stoof
- Group of Plant Vascular Development, Swiss Federal Institute of Technology (ETH) Zurich, 8092 Zurich, Switzerland
| | - Antia Rodriguez-Villalon
- Group of Plant Vascular Development, Swiss Federal Institute of Technology (ETH) Zurich, 8092 Zurich, Switzerland.
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16
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Wendrich JR, Yang B, Vandamme N, Verstaen K, Smet W, Van de Velde C, Minne M, Wybouw B, Mor E, Arents HE, Nolf J, Van Duyse J, Van Isterdael G, Maere S, Saeys Y, De Rybel B. Vascular transcription factors guide plant epidermal responses to limiting phosphate conditions. Science 2020; 370:science.aay4970. [PMID: 32943451 DOI: 10.1126/science.aay4970] [Citation(s) in RCA: 137] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/17/2020] [Accepted: 09/04/2020] [Indexed: 12/25/2022]
Abstract
Optimal plant growth is hampered by deficiency of the essential macronutrient phosphate in most soils. Plant roots can, however, increase their root hair density to efficiently forage the soil for this immobile nutrient. By generating and exploiting a high-resolution single-cell gene expression atlas of Arabidopsis roots, we show an enrichment of TARGET OF MONOPTEROS 5/LONESOME HIGHWAY (TMO5/LHW) target gene responses in root hair cells. The TMO5/LHW heterodimer triggers biosynthesis of mobile cytokinin in vascular cells and increases root hair density during low-phosphate conditions by modifying both the length and cell fate of epidermal cells. Moreover, root hair responses in phosphate-deprived conditions are TMO5- and cytokinin-dependent. Cytokinin signaling links root hair responses in the epidermis to perception of phosphate depletion in vascular cells.
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Affiliation(s)
- Jos R Wendrich
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - BaoJun Yang
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Niels Vandamme
- Data Mining and Modelling for Biomedicine, VIB Center for Inflammation Research, Ghent, Belgium.,Department of Applied Mathematics, Computer Science and Statistics, Ghent University, Ghent, Belgium
| | - Kevin Verstaen
- Data Mining and Modelling for Biomedicine, VIB Center for Inflammation Research, Ghent, Belgium.,Department of Applied Mathematics, Computer Science and Statistics, Ghent University, Ghent, Belgium
| | - Wouter Smet
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Celien Van de Velde
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Max Minne
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Brecht Wybouw
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Eliana Mor
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Helena E Arents
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Jonah Nolf
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Julie Van Duyse
- VIB Flow Core, VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Gert Van Isterdael
- VIB Flow Core, VIB Center for Inflammation Research, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Steven Maere
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Yvan Saeys
- Data Mining and Modelling for Biomedicine, VIB Center for Inflammation Research, Ghent, Belgium. .,Department of Applied Mathematics, Computer Science and Statistics, Ghent University, Ghent, Belgium
| | - Bert De Rybel
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium. .,VIB Center for Plant Systems Biology, Ghent, Belgium
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17
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Kappagantu M, Collum TD, Dardick C, Culver JN. Viral Hacks of the Plant Vasculature: The Role of Phloem Alterations in Systemic Virus Infection. Annu Rev Virol 2020; 7:351-370. [PMID: 32453971 DOI: 10.1146/annurev-virology-010320-072410] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
For plant viruses, the ability to load into the vascular phloem and spread systemically within a host is an essential step in establishing a successful infection. However, access to the vascular phloem is highly regulated, representing a significant obstacle to virus loading, movement, and subsequent unloading into distal uninfected tissues. Recent studies indicate that during virus infection, phloem tissues are a source of significant transcriptional and translational alterations, with the number of virus-induced differentially expressed genes being four- to sixfold greater in phloem tissues than in surrounding nonphloem tissues. In addition, viruses target phloem-specific components as a means to promote their own systemic movement and disrupt host defense processes. Combined, these studies provide evidence that the vascular phloem plays a significant role in the mediation and control of host responses during infection and as such is a site of considerable modulation by the infecting virus. This review outlines the phloem responses and directed reprograming mechanisms that viruses employ to promote their movement through the vasculature.
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Affiliation(s)
- Madhu Kappagantu
- Institute of Bioscience and Biotechnology Research, University of Maryland, College Park, Maryland 20742, USA;
| | - Tamara D Collum
- Foreign Disease-Weed Science Research Unit, US Department of Agriculture Agricultural Research Service, Frederick, Maryland 21702, USA
| | - Christopher Dardick
- Appalachian Fruit Research Station, US Department of Agriculture Agricultural Research Service, Kearneysville, West Virginia 25430, USA
| | - James N Culver
- Institute of Bioscience and Biotechnology Research, University of Maryland, College Park, Maryland 20742, USA; .,Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742, USA
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18
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Gujas B, Kastanaki E, Sturchler A, Cruz TMD, Ruiz-Sola MA, Dreos R, Eicke S, Truernit E, Rodriguez-Villalon A. A Reservoir of Pluripotent Phloem Cells Safeguards the Linear Developmental Trajectory of Protophloem Sieve Elements. Curr Biol 2020; 30:755-766.e4. [PMID: 32037095 DOI: 10.1016/j.cub.2019.12.043] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/15/2019] [Accepted: 12/12/2019] [Indexed: 11/26/2022]
Abstract
Plant cells can change their identity based on positional information, a mechanism that confers developmental plasticity to plants. This ability, common to distinct multicellular organisms, is particularly relevant for plant phloem cells. Protophloem sieve elements (PSEs), one type of phloem conductive cells, act as the main organizers of the phloem pole, which comprises four distinct cell files organized in a conserved pattern. Here, we report how Arabidopsis roots generate a reservoir of meristematic phloem cells competent to swap their cell identities. Although PSE misspecification induces cell identity hybridism, the activity of RECEPTOR LIKE PROTEIN KINASE 2 (RPK2) by perceiving CLE45 peptide contributes to restrict PSE identity to the PSE position. By maintaining a spatiotemporal window when PSE and PSE-adjacent cells' identities are interchangeable, CLE45 signaling endows phloem cells with the competence to re-pattern a functional phloem pole when protophloem fails to form.
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Affiliation(s)
- Bojan Gujas
- Group of Plant Vascular Development, Swiss Federal Institute of Technology (ETH) Zurich, 8092 Zurich, Switzerland
| | - Elizabeth Kastanaki
- Group of Plant Vascular Development, Swiss Federal Institute of Technology (ETH) Zurich, 8092 Zurich, Switzerland
| | - Alessandra Sturchler
- Group of Plant Vascular Development, Swiss Federal Institute of Technology (ETH) Zurich, 8092 Zurich, Switzerland
| | - Tiago M D Cruz
- Group of Plant Vascular Development, Swiss Federal Institute of Technology (ETH) Zurich, 8092 Zurich, Switzerland
| | - M Aguila Ruiz-Sola
- Group of Phloem Development, Swiss Federal Institute of Technology (ETH) Zurich, 8092 Zurich, Switzerland
| | - Rene Dreos
- Group of NCCR RNA and Disease, University of Lausanne, 1015 Lausanne, Switzerland
| | - Simona Eicke
- Group of Phloem Development, Swiss Federal Institute of Technology (ETH) Zurich, 8092 Zurich, Switzerland
| | - Elisabeth Truernit
- Group of Phloem Development, Swiss Federal Institute of Technology (ETH) Zurich, 8092 Zurich, Switzerland
| | - Antia Rodriguez-Villalon
- Group of Plant Vascular Development, Swiss Federal Institute of Technology (ETH) Zurich, 8092 Zurich, Switzerland.
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19
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van Bel AJE, Musetti R. Sieve element biology provides leads for research on phytoplasma lifestyle in plant hosts. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:3737-3755. [PMID: 30972422 DOI: 10.1093/jxb/erz172] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 03/26/2019] [Indexed: 06/09/2023]
Abstract
Phytoplasmas reside exclusively in sieve tubes, tubular arrays of sieve element-companion cell complexes. Hence, the cell biology of sieve elements may reveal (ultra)structural and functional conditions that are of significance for survival, propagation, colonization, and effector spread of phytoplasmas. Electron microscopic images suggest that sieve elements offer facilities for mobile and stationary stages in phytoplasma movement. Stationary stages may enable phytoplasmas to interact closely with diverse sieve element compartments. The unique, reduced sieve element outfit requires permanent support by companion cells. This notion implies a future focus on the molecular biology of companion cells to understand the sieve element-phytoplasma inter-relationship. Supply of macromolecules by companion cells is channelled via specialized symplasmic connections. Ca2+-mediated gating of symplasmic corridors is decisive for the communication within and beyond the sieve element-companion cell complex and for the dissemination of phytoplasma effectors. Thus, Ca2+ homeostasis, which affects sieve element Ca2+ signatures and induces a range of modifications, is a key issue during phytoplasma infection. The exceptional physical and chemical environment in sieve elements seems an essential, though not the only factor for phytoplasma survival.
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Affiliation(s)
- Aart J E van Bel
- Institute of Phytopathology, Centre for BioSystems, Land Use and Nutrition, Justus-Liebig University, Giessen, Germany
| | - Rita Musetti
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
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20
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Abstract
Sugars and other macromolecules arrive in heterotrophic plant tissues through the phloem, a long-distance transport system. Owing to a recent study, we now have a better understanding of how these molecules exit the phloem at their final destinations.
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Affiliation(s)
- Elisabeth Truernit
- Institute of Molecular Plant Biology, ETH Zurich, Universitätsstrasse 2, 8092 Zürich, Switzerland.
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21
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Rodriguez-Villalon A, Brady SM. Single cell RNA sequencing and its promise in reconstructing plant vascular cell lineages. CURRENT OPINION IN PLANT BIOLOGY 2019; 48:47-56. [PMID: 31071514 DOI: 10.1016/j.pbi.2019.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 04/01/2019] [Accepted: 04/02/2019] [Indexed: 06/09/2023]
Abstract
In the last decade, recent advances in single-cell RNA sequencing coupled with computational algorithms have opened new avenues to study the cell type composition of tissues and organs as well as to infer cell developmental trajectories. These technologies have been used to resolve and map atlases of tissues and organs in many animal species as well as to further order cell developmental trajectories. Despite these advances in animals, many of the current plant cell type expression profiles confound multiple developmental stages preventing an accurate monitoring of cell lineage. In this review, we propose how the application of single-cell sequencing will improve our molecular understanding of cell type differentiation. Using root vascular cells as a model, we highlight the potential of single cell transcriptomics as well as its limitations to monitor the progression of vascular maturation. By comparing cell morphology, functionality and gene expression, we aim to provide a new perspective of plant cell type differentiation.
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Affiliation(s)
| | - Siobhan M Brady
- Department of Plant Biology and the Genome Center, University of California, Davis, CA 95616, USA.
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22
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Anne P, Hardtke CS. Phloem function and development-biophysics meets genetics. CURRENT OPINION IN PLANT BIOLOGY 2018; 43:22-28. [PMID: 29278791 DOI: 10.1016/j.pbi.2017.12.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 11/10/2017] [Accepted: 12/12/2017] [Indexed: 05/07/2023]
Abstract
Evolution of the vascular tissues allowed plants to efficiently settle land, occupy new ecological niches, and thereby crucially shape earth's biosphere. Of the two conducting cell types in the plant vasculature, the tubular network of phloem sieve elements transports phloem sap from source to sink organs. Recent years have witnessed the identification of ever more regulators of sieve element differentiation, as well as a more detailed understanding of phloem physiology and function. From molecular regulators of the commitment to sieve element fate, to enzymatic executors of the differentiation process, the toolbox to investigate sieve element formation has been greatly enlarged. To connect the various players in different genetic layers, and thus to ultimately attain a comprehensive description and understanding of sieve element development at the molecular level, appears to be within reach.
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Affiliation(s)
- Pauline Anne
- Department of Plant Molecular Biology, University of Lausanne, Biophore Building, CH-1015 Lausanne, Switzerland
| | - Christian S Hardtke
- Department of Plant Molecular Biology, University of Lausanne, Biophore Building, CH-1015 Lausanne, Switzerland.
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23
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Ainsworth EA, Lemonnier P. Phloem function: a key to understanding and manipulating plant responses to rising atmospheric [CO 2]? CURRENT OPINION IN PLANT BIOLOGY 2018; 43:50-56. [PMID: 29329037 DOI: 10.1016/j.pbi.2017.12.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/01/2017] [Accepted: 12/10/2017] [Indexed: 06/07/2023]
Abstract
Increasing atmospheric carbon dioxide concentration ([CO2]) directly stimulates photosynthesis and reduces stomatal conductance in C3 plants. Both of these physiological effects have the potential to alter phloem function at elevated [CO2]. Recent research has clearly established that photosynthetic capacity is correlated to vascular traits associated with phloem loading and water transport, but the effects of elevated [CO2] on these relationships are largely unexplored. Plants also employ different strategies for loading sucrose and other sugars into the phloem, and there is potential for species with different phloem loading strategies to respond differently to elevated [CO2]. Recent research manipulating sucrose transporters and other key enzymes with roles in phloem loading show promise for maximizing crop performance in an elevated [CO2] world.
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Affiliation(s)
- Elizabeth A Ainsworth
- USDA ARS Global Change and Photosynthesis Research Unit, 1201 W. Gregory Drive, Urbana, IL 61801, USA; Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana, Champaign, USA.
| | - Pauline Lemonnier
- USDA ARS Global Change and Photosynthesis Research Unit, 1201 W. Gregory Drive, Urbana, IL 61801, USA; Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana, Champaign, USA
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24
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Chen Q, Payyavula RS, Chen L, Zhang J, Zhang C, Turgeon R. FLOWERING LOCUS T mRNA is synthesized in specialized companion cells in Arabidopsis and Maryland Mammoth tobacco leaf veins. Proc Natl Acad Sci U S A 2018; 115:2830-2835. [PMID: 29483267 PMCID: PMC5856545 DOI: 10.1073/pnas.1719455115] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Flowering is triggered by the transmission of a mobile protein, FLOWERING LOCUS T (FT), from leaves to the shoot apex. FT originates in the phloem of leaf veins. However, the identity of the FT-synthesizing cells in the phloem is not known. As a result, it has not been possible to determine whether the complex regulatory networks that control FT synthesis involve intercellular communication, as is the case in many aspects of plant development. We demonstrate here that FT in Arabidopsis thaliana and FT orthologs in Maryland Mammoth tobacco (Nicotiana tabacum) are produced in two unique files of phloem companion cells. These FT-activating cells, visualized by fluorescent proteins, also activate the GALACTINOL SYNTHASE (CmGAS1) promoter from melon (Cucumis melo). Ablating the cells by expression of the diphtheria toxin gene driven by the CmGAS1 promoter delays flowering in both Arabidopsis and Maryland Mammoth tobacco. In Arabidopsis, toxin expression reduces expression of FT and flowering-associated genes downstream, but not upstream, of FT Our results indicate that specific companion cells mediate the essential flowering function. Since the identified cells are present in the minor veins of two unrelated dicotyledonous species, this may be a widespread phenomenon.
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Affiliation(s)
- Qingguo Chen
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853
| | - Raja S Payyavula
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853
| | - Lin Chen
- College of Agronomy, Nanjing Agricultural University, Nanjing, 210095 Jiangsu, China
| | - Jing Zhang
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853
| | - Cankui Zhang
- Department of Agronomy, Purdue University, West Lafayette, IN 49707;
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 49707
| | - Robert Turgeon
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853;
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25
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Ross-Elliott TJ, Jensen KH, Haaning KS, Wager BM, Knoblauch J, Howell AH, Mullendore DL, Monteith AG, Paultre D, Yan D, Otero S, Bourdon M, Sager R, Lee JY, Helariutta Y, Knoblauch M, Oparka KJ. Phloem unloading in Arabidopsis roots is convective and regulated by the phloem-pole pericycle. eLife 2017; 6. [PMID: 28230527 PMCID: PMC5365319 DOI: 10.7554/elife.24125] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 02/17/2017] [Indexed: 02/05/2023] Open
Abstract
In plants, a complex mixture of solutes and macromolecules is transported by the phloem. Here, we examined how solutes and macromolecules are separated when they exit the phloem during the unloading process. We used a combination of approaches (non-invasive imaging, 3D-electron microscopy, and mathematical modelling) to show that phloem unloading of solutes in Arabidopsis roots occurs through plasmodesmata by a combination of mass flow and diffusion (convective phloem unloading). During unloading, solutes and proteins are diverted into the phloem-pole pericycle, a tissue connected to the protophloem by a unique class of ‘funnel plasmodesmata’. While solutes are unloaded without restriction, large proteins are released through funnel plasmodesmata in discrete pulses, a phenomenon we refer to as ‘batch unloading’. Unlike solutes, these proteins remain restricted to the phloem-pole pericycle. Our data demonstrate a major role for the phloem-pole pericycle in regulating phloem unloading in roots. DOI:http://dx.doi.org/10.7554/eLife.24125.001 A mechanism called photosynthesis allows plants to use energy from sunlight to make sugars from carbon dioxide gas and water. These sugars can then be used as fuel, or as building blocks for wood and other plant structures. Every part of the plant requires sugars, but most photosynthesis happens in the leaves and stems, so the sugars need to be able to move around the plant to wherever they are needed. Phloem tubes form a network that transports sugar, proteins and other molecules around the plant within a fluid known as sap. Because this network is so extensive, it is very difficult to study, which has left researchers with major questions about how it works. For example, it is not clear how the sugar and other molecules leave the phloem when they reach their destination. Ross-Elliot et al. used a combination of microscopy and mathematical modeling to investigate how sugars and other molecules leave the phloem in the roots of a plant called Arabidopsis thaliana. The experiments show that these molecules move directly into cells within a neighboring tissue called the phloem-pole pericycle via pores known as funnel plasmodesmata. Ross-Elliot et al. incorporated the experimental data into a mathematical model of phloem unloading. This model suggests that sugars and other small molecules move freely through the funnel plasmodesmata, but large proteins pass through these pores in pulses. Future challenges include finding out exactly how plants control phloem unloading and to investigate whether it is possible to modify the delivery of specific molecules to particular parts of the plant. DOI:http://dx.doi.org/10.7554/eLife.24125.002
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Affiliation(s)
| | - Kaare H Jensen
- Department of Physics, Technical University of Denmark, Lyngby, Denmark
| | - Katrine S Haaning
- Department of Physics, Technical University of Denmark, Lyngby, Denmark
| | - Brittney M Wager
- School of Biological Sciences, Washington State University, Pullman, United States
| | - Jan Knoblauch
- School of Biological Sciences, Washington State University, Pullman, United States
| | - Alexander H Howell
- School of Biological Sciences, Washington State University, Pullman, United States
| | - Daniel L Mullendore
- School of Biological Sciences, Washington State University, Pullman, United States
| | - Alexander G Monteith
- Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford, United Kingdom
| | - Danae Paultre
- Institute of Molecular Plant Science, University of Edinburgh, Edinburgh, United Kingdom
| | - Dawei Yan
- Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Sofia Otero
- Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Matthieu Bourdon
- Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Ross Sager
- Department of Plant and Soil Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, United States
| | - Jung-Youn Lee
- Department of Plant and Soil Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, United States
| | - Ykä Helariutta
- Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Michael Knoblauch
- School of Biological Sciences, Washington State University, Pullman, United States
| | - Karl J Oparka
- Institute of Molecular Plant Science, University of Edinburgh, Edinburgh, United Kingdom
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Etchells JP, Turner SR. Realizing pipe dreams - a detailed picture of vascular development. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:1-4. [PMID: 28013229 PMCID: PMC5183087 DOI: 10.1093/jxb/erw482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Affiliation(s)
- J Peter Etchells
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK,
| | - Simon R Turner
- Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, UK
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Abstract
Vascular tissue, comprising xylem and phloem, is responsible for the transport of water and nutrients throughout the plant body. Such tissue is continually produced from stable populations of stem cells, specifically the procambium during primary growth and the cambium during secondary growth. As the majority of plant biomass is produced by the cambium, there is an obvious demand for an understanding of the genetic mechanisms that control the rate of vascular cell division. Moreover, wood is an industrially important product of the cambium, and research is beginning to uncover similar mechanisms in trees such as poplar. This review focuses upon recent work that has identified the major molecular pathways that regulate procambial and cambial activity.
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Affiliation(s)
- Liam Campbell
- University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Simon Turner
- University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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