Phloem unloading in Arabidopsis roots is convective and regulated by the phloem-pole pericycle
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 mathe...
| Main Authors: | , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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eLife Sciences Publications Ltd
2017-02-01
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| Series: | eLife |
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| Online Access: | https://elifesciences.org/articles/24125 |
| _version_ | 1811180378783744000 |
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| author | Timothy J Ross-Elliott Kaare H Jensen Katrine S Haaning Brittney M Wager Jan Knoblauch Alexander H Howell Daniel L Mullendore Alexander G Monteith Danae Paultre Dawei Yan Sofia Otero Matthieu Bourdon Ross Sager Jung-Youn Lee Ykä Helariutta Michael Knoblauch Karl J Oparka |
| author_facet | Timothy J Ross-Elliott Kaare H Jensen Katrine S Haaning Brittney M Wager Jan Knoblauch Alexander H Howell Daniel L Mullendore Alexander G Monteith Danae Paultre Dawei Yan Sofia Otero Matthieu Bourdon Ross Sager Jung-Youn Lee Ykä Helariutta Michael Knoblauch Karl J Oparka |
| author_sort | Timothy J Ross-Elliott |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-04-11T09:01:01Z |
| format | Article |
| id | doaj.art-dd4aab87e524416492cee6e67c939fa8 |
| institution | Directory Open Access Journal |
| issn | 2050-084X |
| language | English |
| last_indexed | 2024-04-11T09:01:01Z |
| publishDate | 2017-02-01 |
| publisher | eLife Sciences Publications Ltd |
| record_format | Article |
| series | eLife |
| spelling | doaj.art-dd4aab87e524416492cee6e67c939fa82022-12-22T04:32:46ZengeLife Sciences Publications LtdeLife2050-084X2017-02-01610.7554/eLife.24125Phloem unloading in Arabidopsis roots is convective and regulated by the phloem-pole pericycleTimothy J Ross-Elliott0https://orcid.org/0000-0002-0991-9588Kaare H Jensen1https://orcid.org/0000-0003-0787-5283Katrine S Haaning2Brittney M Wager3https://orcid.org/0000-0001-9679-659XJan Knoblauch4https://orcid.org/0000-0002-8952-3961Alexander H Howell5https://orcid.org/0000-0001-6735-0660Daniel L Mullendore6Alexander G Monteith7https://orcid.org/0000-0003-1731-0446Danae Paultre8Dawei Yan9https://orcid.org/0000-0001-8256-0279Sofia Otero10https://orcid.org/0000-0001-9409-8544Matthieu Bourdon11Ross Sager12Jung-Youn Lee13Ykä Helariutta14Michael Knoblauch15https://orcid.org/0000-0003-0391-9891Karl J Oparka16https://orcid.org/0000-0002-8035-5076School of Biological Sciences, Washington State University, Pullman, United StatesDepartment of Physics, Technical University of Denmark, Lyngby, DenmarkDepartment of Physics, Technical University of Denmark, Lyngby, DenmarkSchool of Biological Sciences, Washington State University, Pullman, United StatesSchool of Biological Sciences, Washington State University, Pullman, United StatesSchool of Biological Sciences, Washington State University, Pullman, United StatesSchool of Biological Sciences, Washington State University, Pullman, United StatesDepartment of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford, United KingdomInstitute of Molecular Plant Science, University of Edinburgh, Edinburgh, United KingdomSainsbury Laboratory, University of Cambridge, Cambridge, United KingdomSainsbury Laboratory, University of Cambridge, Cambridge, United KingdomSainsbury Laboratory, University of Cambridge, Cambridge, United KingdomDepartment of Plant and Soil Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, United StatesDepartment of Plant and Soil Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, United StatesSainsbury Laboratory, University of Cambridge, Cambridge, United KingdomSchool of Biological Sciences, Washington State University, Pullman, United StatesInstitute of Molecular Plant Science, University of Edinburgh, Edinburgh, United KingdomIn 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.https://elifesciences.org/articles/24125phloemfunnel plasmodesmatalong distance signalingphloem unloadingprotophloemphloem pole pericycle |
| spellingShingle | Timothy J Ross-Elliott Kaare H Jensen Katrine S Haaning Brittney M Wager Jan Knoblauch Alexander H Howell Daniel L Mullendore Alexander G Monteith Danae Paultre Dawei Yan Sofia Otero Matthieu Bourdon Ross Sager Jung-Youn Lee Ykä Helariutta Michael Knoblauch Karl J Oparka Phloem unloading in Arabidopsis roots is convective and regulated by the phloem-pole pericycle eLife phloem funnel plasmodesmata long distance signaling phloem unloading protophloem phloem pole pericycle |
| title | Phloem unloading in Arabidopsis roots is convective and regulated by the phloem-pole pericycle |
| title_full | Phloem unloading in Arabidopsis roots is convective and regulated by the phloem-pole pericycle |
| title_fullStr | Phloem unloading in Arabidopsis roots is convective and regulated by the phloem-pole pericycle |
| title_full_unstemmed | Phloem unloading in Arabidopsis roots is convective and regulated by the phloem-pole pericycle |
| title_short | Phloem unloading in Arabidopsis roots is convective and regulated by the phloem-pole pericycle |
| title_sort | phloem unloading in arabidopsis roots is convective and regulated by the phloem pole pericycle |
| topic | phloem funnel plasmodesmata long distance signaling phloem unloading protophloem phloem pole pericycle |
| url | https://elifesciences.org/articles/24125 |
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