The photosynthetic carbon assimilation rates were measured as NaHCO 3 1. Chloroplasts as source and target of cellular redox regulation: Chloroplasts generated reducing equivalents may be transferred to mitochondria through several metabolite shuttles that operate between the two compartments. Reactive oxygen species as signals that modulate plant stress responses and programmed cell death. This flexibility in mitochondrial electron transport chain is also observed in the present study during hyper-osmotic stress and sub-optimal temperature stress as evident by a significant increase in the capacity of AOX pathway with a concomitant decrease in the capacity of COX pathway Figures 2A , B. Inhibition of the light activation of light regulated enzymes fructose-1,6-bisphosphatase, sedoheptulose-1,7-bisphosphatase and ribulose-1,5-bisphosphate carboxylase is also one of the reason for decreased photosynthesis during cold stress Krause et al. Mitochondrial contribution to photosynthetic metabolism.
|Date Added:||16 August 2004|
|File Size:||11.61 Mb|
|Operating Systems:||Windows NT/2000/XP/2003/2003/7/8/10 MacOS 10/X|
|Price:||Free* [*Free Regsitration Required]|
Pea plants Pisum sativum L. The results indicated that the optimal conditions to achieve maximum photosynthetic performance carbon assimilation and respiratory rates in mesophyll protoplasts as indicated by rates of NaHCO 3 -dependent O 2 evolution and O 2 uptake, respectively, were found to be at an osmoticum of 0. Redox sensing and signaling associated with reactive oxygen in chloroplasts, peroxisomes and mitochondria.
The existence of phospholipase A 2 activity in plant mitochondria and its activation by hyperosmotic stress in durum wheat Triticum durum Desf.
Importance of AOX pathway in optimizing photosynthesis under high light stress: A similar trend was observed in response to sub-optimal temperature stress.
Via S Driver – covers-files
The redox state of free nicotinamide adenine dinucleotide phosphate in the cytoplasm of rat liver. This means that you will not need to remember your user name and password in the future and you will be able to login with the account you choose to sync, with the click of a button. The electron partitioning between the cytochrome and alternative respiratory pathways during chilling recovery in two cultivars of maize differing in chilling sensitivity.
Different respiration metabolism between mycorrhizal and non-mycorrhizal rice under low-temperature stress: The samples were homogenized in 50 mM phosphate buffer pH 7. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets. Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions.
Alternative oxidase impacts the plant response to biotic stress by influencing the mitochondrial generation of reactive oxygen species.
The proteins separated on We will be provided with an authorization token please note: To fully activate the enzyme, supernatant 2.
The flexibility of the mitochondrial electron transport chain to divert electrons from phosphorylating to non-phosphorylating pathways decrease the over reduction of the electron transport chain components and ROS generation.
The capacity of AOX pathway increased significantly in parallel to increase in intracellular pyruvate and reactive oxygen species ROS levels under both hyper-osmotic stress and sub-optimal temperature stress under the background of saturating light. It is easily permeable through the plasma membrane and at the concentration 0.
Regulation of alternative oxidase activity in 815885 plants. The reaction is initiated by the addition of 30U MDH as the concentration of malate is proportional to the amount of NAD reduced at nm Heineke et al.
The intracellular levels of pyruvate were measured spectrophotometrically using enzymatic assay coupled to NADH oxidation as described in Dinakar et al. Determination of glutathione and glutathione disulfide using glutathione reductase and 2-vinyl-pyridine. Further, the light intensity applied to vi maximal rates of photosynthesis is known to vary in mesophyll protoplasts isolated from different leaves Riazunnisa et al.
Any deviation from the optimized conditions, i. The absence of alternative oxidase 1a in Arabidopsis thaliana results in acute sensitivity to combined light and drought stress. Therefore, the present study was performed using mesophyll protoplasts of pea as the model system to examine the importance of AOX pathway over COX pathway and its coordination with malate valve and glutathione redox system in regulating cellular ROS to optimize photosynthesis under hyper-osmotic and sub-optimal temperature stresses.
Activation of the plant mitochondrial potassium channel by free fatty acids and acyl-coA esters: Conceived and designed the experiments: Temperature effects on the activity of the alternative respiratory pathway in chill-sensitive Cucumis sativus. Importance of oxidative electron transport over oxidative phosphorylation in optimizing photosynthesis in mesophyll protoplasts of pea Pisum sativum L. The mitochondrial cyanide-resistant oxidase: Up-regulation of mitochondrial alternative oxidase concomitant with chloroplast over-reduction by excess light.
Protein estimation was done according to the method of Lowry et al.