Vacuolar Transport of Abscisic Acid Glucosyl Ester Is Mediated by ATP-Binding Cassette and Proton-Antiport Mechanisms in Arabidopsis1
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SCOPUS
- Title
- Vacuolar Transport of Abscisic Acid Glucosyl Ester Is Mediated by ATP-Binding Cassette and Proton-Antiport Mechanisms in Arabidopsis1
- Authors
- Burla, B; Pfrunder, S; Nagy, R; Francisco, RM; Lee, Y; Martinoia, E
- Date Issued
- 2013-11
- Publisher
- Plant Physiology
- Abstract
- Abscisic acid (ABA) is a key plant hormone involved in diverse physiological and developmental processes, including abiotic stress responses and the regulation of stomatal aperture and seed germination. Abscisic acid glucosyl ester (ABA-GE) is a hydrolyzable ABA conjugate that accumulates in the vacuole and presumably also in the endoplasmic reticulum. Deconjugation of ABA-GE by the endoplasmic reticulum and vacuolar b-glucosidases allows the rapid formation of free ABA in response to abiotic stress conditions such as dehydration and salt stress. ABA-GE further contributes to the maintenance of ABA homeostasis, as it is the major ABA catabolite exported from the cytosol. In this work, we identified that the import of ABA-GE into vacuoles isolated from Arabidopsis (Arabidopsis thaliana) mesophyll cells is mediated by two distinct membrane transport mechanisms: proton gradientdriven and ATP-binding cassette (ABC) transporters. Both systems have similarKm values of approximately 1mM. According to our estimations, this low affinity appears nevertheless to be sufficient for the continuous vacuolar sequestration ofABA-GE produced in the cytosol. We further demonstrate that two tested multispecific vacuolar ABCC-type ABC transporters from Arabidopsis exhibit ABA-GE transport activity when expressed in yeast (Saccharomyces cerevisiae), which also supports the involvement of ABC transporters in ABA-GE uptake. Our findings suggest that the vacuolar ABA-GE uptake is not mediated by specific, but rather by several, possibly multispecific, transporters that are involved in the general vacuolar sequestration of conjugated metabolites.
- Keywords
- D-GLUCOPYRANOSYL ABSCISATE; ARABIDOPSIS-THALIANA; SACCHAROMYCES-CEREVISIAE; ABC TRANSPORTERS; PHYTOCHELATIN TRANSPORTERS; MEDICAGO-TRUNCATULA; BARLEY MESOPHYLL; SEED DEVELOPMENT; CELL-CULTURE; RESISTANCE
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/14902
- DOI
- 10.1104/PP.113.222547
- ISSN
- 0032-0889
- Article Type
- Article
- Citation
- Plant Physiology, vol. 163, no. 3, page. 1446 - 1458, 2013-11
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- There are no files associated with this item.
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