Distinct plastid fructose bisphosphate aldolases function in photosynthetic and non-photosynthetic metabolism in Arabidopsis
© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Experimental Biology.
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 72(2021), 10 vom: 04. Mai, Seite 3739-3755 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2021
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Arabidopsis thaliana 6-bisphosphate aldolase Amino acid metabolism Calvin–Benson cycle fructose-1 glycolysis phloem transport photosynthesis mehr... |
| Zusammenfassung: | © The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Experimental Biology. Plastid metabolism is critical in both photoautotrophic and heterotrophic plant cells. In chloroplasts, fructose-1,6-bisphosphate aldolase (FBA) catalyses the formation of both fructose 1,6-bisphosphate and sedoheptulose 1,7-bisphosphate within the Calvin-Benson cycle. Three Arabidopsis genes, AtFBA1-AtFBA3, encode plastidial isoforms of FBA, but the contribution of each isoform is unknown. Phylogenetic analysis indicates that FBA1 and FBA2 derive from a recently duplicated gene, while FBA3 is a more ancient paralog. fba1 mutants are phenotypically indistinguishable from the wild type, while both fba2 and fba3 have reduced growth. We show that FBA2 is the major isoform in leaves, contributing most of the measurable activity. Partial redundancy with FBA1 allows both single mutants to survive, but combining both mutations is lethal, indicating a block of photoautotrophy. In contrast, FBA3 is expressed predominantly in heterotrophic tissues, especially the leaf and root vasculature, but not in the leaf mesophyll. We show that the loss of FBA3 affects plastidial glycolytic metabolism of the root, potentially limiting the biosynthesis of essential compounds such as amino acids. However, grafting experiments suggest that fba3 is dysfunctional in leaf phloem transport, and we suggest that a block in photoassimilate export from leaves causes the buildup of high carbohydrate concentrations and retarded growth |
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| Beschreibung: | Date Completed 21.05.2021 Date Revised 01.12.2021 published: Print Citation Status MEDLINE |
| ISSN: | 1460-2431 |
| DOI: | 10.1093/jxb/erab099 |