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12.01.2021 10:00
Comprehensive characterization of the vascular structure of plants
Biology: Key Publication in The Plant Cell
Two teams of plant researchers and bioinformaticians funded by the Alexander von Humboldt Foundation and led by Heinrich Heine University Düsseldorf (HHU) have succeeded for the first time in identifying the functions of the different cell types in the vascular system of the leaves of plants. They present their basic results in the current issue of the journal “The Plant Cell”.
The vascular system of the plant leaves plays a key role in the transport of dissolved substances from their place of origin – e.g. from the photosynthesis-driving leaf cells – to their storage or use locations. Sugar and amino acids are transported from the leaves to the roots and seeds via the pathways.
The phloem is the part of the vascular bundle in vascular plants that consists of the sieve elements – in which the actual transport takes place – and their accompanying cells, as well as the accompanying parenchymal cells. In the leaf veins there are at least seven different cell types with specific roles in transport, metabolism and signal transmission.
Little is known about the vascular cells in leaves, especially the functional cells in them (the phloem parenchyma, PP for short). Two teams of Alexander von Humboldt professorships in Düsseldorf and Tübingen, a colleague from Champaign Urbana in Illinois / USA and a bioinformatics chair from Düsseldorf present the first comprehensive analysis of the vascular cells in the leaves of thale cress (Arabidopsis thaliana) using single cell sequencing.
The team of Alexander von Humboldt Professor Dr. Marja Timmermans from the University of Tübingen recently used individual sequencing in plants to characterize the cells of the roots. Researchers from the team led by Alexander von Humboldt Professor Dr. Wolf Frommer in Düsseldorf used her to isolate the cells from leaves for the first time in order to create an atlas of all the controlling RNA molecules (the transcriptome) of the leaf vascular system. By analyzing the metabolic pathways, they were able to define the role of the different cells.
Among other things, the research team demonstrated for the first time that transport proteins for sugar (SWEET) and amino acids (UmamiT) are formed in the parenchymal cells, which transport these substances from their production sites into the pipeline system. These are then actively imported into the sieve element escort cell complex via a second transport substitute (SUT or AAP) and then exported from the sheet.
In these comprehensive investigations, biologists played hand in hand with HHU bioinformaticians led by Prof. Dr. Martin Lercher and were able to establish that phloem parenchyma and escort cells have complementary metabolic pathways and are therefore able to control the composition of the phloem sap.
First author and working group leader Dr. Ji-Yun Kim from the HHU emphasizes: “Our analysis provides completely new insights into the leaf vascular system and the role and relationship of the individual leaf cell types.” Institute director Prof. Frommer adds: “The cooperation of the four working groups made it possible to use new methods to To gain insights into the important cells in the pathways of plants for the first time and thus to gain a basis for a better understanding of the transport of substances in plants. ”
Originalpublikation:
Ji-Yun Kim, Efthymia Symeonidi, Tin Yau Pang, Tom Denyer, Diana Weidauer, Margaret Bezrutczyk, Manuel Miras, Nora Zöllner, Thomas Hartwig, Michael M. Wudick, Martin Lercher, Li-Qing Chen, Marja C.P Timmermans & Wolf B. Frommer, Distinct identities of leaf phloem cells revealed by single cell transcriptomics, The Plant Cell, 2021
DOI: 10.1093/plcell/koaa060
Features of this press release:
Journalists, scientists
Biology, animal / land / forest, environment / ecology
supraregional
Research results, scientific publications
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