www.uhasselt.be
DSpace

Document Server@UHasselt >
Research >
Research publications >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/3187

Title: Low-oxygen stress and water deficit induce cytosolic pyruvate orthophosphate dikinase (PPDK) expression in roots of rice, a C-3 plant
Authors: Moons, A.
VALCKE, Roland
Van Montagu, M
Issue Date: 1998
Publisher: BLACKWELL SCIENCE LTD
Citation: PLANT JOURNAL, 15(1). p. 89-98
Abstract: Pyruvate orthophosphate dikinase (PPDK) is known for its role in C-4 photosynthesis but has no established function in C-3 plants. Abscisic acid, PEG and submergence were found to markedly induce a protein of about 97 kDa, identified by microsequencing as PPDK, in rice roots (C3) The rice genome was found to contain two ppdk loci, osppdka and osppdkb. We isolated osppdka cDNA, which encodes a cytosolic rice PPDK isoform of 96.6 kDa, that corresponded to the ABA-induced protein from roots. Western blot analysis showed a PPDK induction in roots of rice seedlings during gradual drying, cold, high salt and mannitol treatment, indicating a water deficit response. PPDK was also induced in the roots and sheath of submerged rice seedlings, and in etiolated rice seedlings exposed to an oxygen-free Na atmosphere, which indicated a low-oxygen stress response. None of the stress treatments induced PPDK protein accumulation in the lamina of green rice seedlings. Ppdk transcripts were found to accumulate in roots of submerged seedlings, concomitant with the induction of alcohol dehydrogenase I. Low-oxygen stress triggered an increase in PPDK activity in roots and etiolated rice seedlings, accompanied by increases in phosphoenolpyruvate carboxylase and malate dehydrogenase activities. The results indicate that cytosolic PPDK is involved in a metabolic response to water deficit and low-oxygen stress in rice, an anoxia-tolerant species.
Notes: Univ Gent VIB, Dept Genet, Genet Lab, B-9000 Ghent, Belgium. Limburgs Univ Ctr, Dept SBG, Lab Plantenfysiol, B-3590 Diepenbeek, Belgium.Moons, A, Univ Montreal, Dept Biochem, POB 6128,Stn Ctr Ville, Montreal, PQ H3C 3J7, Canada.moonsa@magellan.umontreal.ca
URI: http://hdl.handle.net/1942/3187
ISI #: 000075109800009
ISSN: 0960-7412
Type: Journal Contribution
Validation: ecoom, 1999
Appears in Collections: Research publications

Files in This Item:

There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.