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Importance of ROS and antioxidant system during the beneficial interactions of mitochondrial metabolism with photosynthetic carbon assimilation.
- Source :
-
Planta [Planta] 2010 Jan; Vol. 231 (2), pp. 461-74. Date of Electronic Publication: 2009 Nov 27. - Publication Year :
- 2010
-
Abstract
- The present study suggests the importance of reactive oxygen species (ROS) and antioxidant metabolites as biochemical signals during the beneficial interactions of mitochondrial metabolism with photosynthetic carbon assimilation at saturating light and optimal CO2. Changes in steady-state photosynthesis of pea mesophyll protoplasts monitored in the presence of antimycin A [AA, inhibitor of cytochrome oxidase (COX) pathway] and salicylhydroxamic acid [SHAM, inhibitor of alternative oxidase (AOX) pathway] were correlated with total cellular ROS and its scavenging system. Along with superoxide dismutase (SOD) and catalase (CAT), responses of enzymatic components--ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), glutathione reductase (GR) and non-enzymatic redox components of ascorbate-glutathione (Asc-GSH) cycle, which play a significant role in scavenging cellular ROS, were examined in the presence of mitochondrial inhibitors. Both AA and SHAM caused marked reduction in photosynthetic carbon assimilation with concomitant rise in total cellular ROS. Restriction of electron transport through COX or AOX pathway had differential effect on ROS generating (SOD), ROS scavenging (CAT and APX) and antioxidant (Asc and GSH) regenerating (MDAR and GR) enzymes. Further, restriction of mitochondrial electron transport decreased redox ratios of both Asc and GSH. However, while decrease in redox ratio of Asc was more prominent in the presence of SHAM in light compared with dark, decrease in redox ratio of GSH was similar in both dark and light. These results suggest that the maintenance of cellular ROS at optimal levels is a prerequisite to sustain high photosynthetic rates which in turn is regulated by respiratory capacities of COX and AOX pathways.
- Subjects :
- Antimycin A pharmacology
Chloroplasts drug effects
Chloroplasts metabolism
Chloroplasts radiation effects
Electron Transport drug effects
Electron Transport radiation effects
Light
Microscopy, Confocal
Mitochondria drug effects
Mitochondria radiation effects
Pisum sativum drug effects
Pisum sativum enzymology
Pisum sativum radiation effects
Plant Leaves cytology
Plant Leaves drug effects
Plant Leaves metabolism
Plant Leaves radiation effects
Protoplasts cytology
Protoplasts drug effects
Protoplasts enzymology
Protoplasts radiation effects
Salicylamides pharmacology
Antioxidants metabolism
Carbon metabolism
Mitochondria metabolism
Photosynthesis drug effects
Photosynthesis radiation effects
Reactive Oxygen Species metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1432-2048
- Volume :
- 231
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Planta
- Publication Type :
- Academic Journal
- Accession number :
- 19943171
- Full Text :
- https://doi.org/10.1007/s00425-009-1067-3