Expression of a cloned sweet potato catalase SPCAT1 alleviates ethephon-mediated leaf senescence and H₂O₂ elevation
Copyright © 2011 Elsevier GmbH. All rights reserved.
| Veröffentlicht in: | Journal of plant physiology. - 1979. - 169(2012), 1 vom: 01. Jan., Seite 86-97 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2012
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| Zugriff auf das übergeordnete Werk: | Journal of plant physiology |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't DNA, Complementary DNA, Plant Organophosphorus Compounds Plant Growth Regulators Plant Proteins Hydrogen Peroxide BBX060AN9V Catalase mehr... |
| Zusammenfassung: | Copyright © 2011 Elsevier GmbH. All rights reserved. In this report a full-length cDNA, SPCAT1, was isolated from ethephon-treated mature L3 leaves of sweet potato. SPCAT1 contained 1479 nucleotides (492 amino acids) in its open reading frame, and exhibited high amino acid sequence identities (ca. 71.2-80.9%) with several plant catalases, including Arabidopsis, eggplant, grey mangrove, pea, potato, tobacco and tomato. Gene structural analysis showed that SPCAT1 encoded a catalase and contained a putative conserved internal peroxisomal targeting signal PTS1 motif and calmodulin binding domain around its C-terminus. RT-PCR showed that SPCAT1 gene expression was enhanced significantly in mature L3 and early senescent L4 leaves and was much reduced in immature L1, L2 and completely yellowing senescent L5 leaves. In dark- and ethephon-treated L3 leaves, SPCAT1 expression was significantly enhanced temporarily from 0 to 24h, then decreased gradually until 72h after treatment. SPCAT1 gene expression levels also exhibited approximately inverse correlation with the qualitative and quantitative H(2)O(2) amounts. Effector treatment showed that ethephon-enhanced SPCAT1 expression was repressed by antioxidant reduced glutathione, NADPH oxidase inhibitor diphenylene iodonium (DPI), calcium ion chelator EGTA and de novo protein synthesis inhibitor cycloheximide. These data suggest that elevated reactive oxygen species H(2)O(2), NADPH oxidase, external calcium influx and de novo synthesized proteins are required and associated with ethephon-mediated enhancement of sweet potato catalase SPCAT1 expression. Exogenous application of expressed catalase SPCAT1 fusion protein delayed or alleviated ethephon-mediated leaf senescence and H(2)O(2) elevation. Based on these data we conclude that sweet potato SPCAT1 is an ethephon-inducible peroxisomal catalase, and its expression is regulated by reduced glutathione, DPI, EGTA and cycloheximide. Sweet potato catalase SPCAT1 may play a physiological role or function in cope with H(2)O(2) homeostasis in leaves caused by developmental cues and environmental stimuli |
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| Beschreibung: | Date Completed 17.09.2012 Date Revised 30.09.2020 published: Print-Electronic GENBANK: GU230147 Citation Status MEDLINE |
| ISSN: | 1618-1328 |
| DOI: | 10.1016/j.jplph.2011.08.002 |