Impact of mitochondrial alternative oxidase expression on the response of Nicotiana tabacum to cold temperature. The effects of cold stress on photosynthesis in Hibiscus plants. Diffusive and metabolic limitations to photosynthesis under drought and salinity in C3 plants. Effects of allelochemicals on plant respiration and oxygen isotope fractionation by the alternative oxidase. The levels of oxoglutarate, aspartate and glutamate were determined as described in Bergmeyer by enzymatic assays coupled to NAD H oxidation or reduction. The alternative oxidase of plant mitochondria is involved in the acclimation of shoot growth at low temperature. Prolongation of photosynthetic induction as a consequence of interference with mitochondrial oxidative metabolism in mesophyll protoplasts of pea Pisum sativum L.

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Physiological impact of mitochondrial alternative oxidase on photosynthesis and growth in Arabidopsis thaliana. The ability of AOX pathway to maintain flux in the cold was suggested to be due to 815855 its reduced vvia to temperature as compared to COX pathway Kiener and Bramlage, ; McNulty and Cummins, ; Stewart et al.

Chloroplasts generated reducing equivalents may be transferred to mitochondria through several metabolite shuttles that operate between the two compartments. Impact of mitochondrial alternative oxidase expression on the response of Nicotiana tabacum to cold temperature. The low concentration of SHAM 0. In soyabean and wheat, water stress caused a significant shift of electrons from the COX to the AOX pathway while in leaves of bean and pepper water stress decreased SHAM-resistant respiration, with no effect on cyanide-resistant respiration Gonzalez-Meler et al.

A similar trend was observed in response to sub-optimal temperature stress. The responses of photosynthesis and respiration in mesophyll protoplasts varied when pre-incubated under hyper-osmoticum or sub-optimal temperature stresses. Water stress drastically reduces root growth and inulin yield in Cichorium intybus var.


The O 2 evolution rates Taken together, the results from the present study demonstrate that the AOX pathway play a significant role in optimizing 11617 by regulating cellular ROS through redox couples related to z valve, antioxidative system and pyridine nucleotides. The effect of growth and measurement temperature on the activity of the alternative pathway. No use, distribution 117 reproduction is permitted which does not comply with these terms.

Respiratory energy demand for protein turnover and ion transport in wheat leaves upon water demand.

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Characterization of alternative oxidase AOX gene expression in response to methyl salicylate and methyl jasmonate pre-treatment and low temperature in tomatoes.

The decrease in A was monitored for 3 min and concentrations of corresponding pyridine nucleotides were calculated using relevant standards Vishwakarma et al.

Similar observations were a reported by Saradadevi and Raghavendrawhere the photosynthetic rates of mesophyll protoplasts decreased to a significant extent on exposure to solutions of increasing osmolarity. Their results suggested that the increase in AOX pathway activity was due to direct inhibition of the COX pathway activity.

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Importance of AOX pathway in optimizing photosynthesis under high light stress: Results Photosynthetic Carbon Assimilation and Respiration in Mesophyll Protoplasts Pre-incubated Under Hyper-Osmoticum and Sub-Optimal Temperatures at Saturating D In the study, the effect of hyper-osmotic stress and sub-optimal temperature stress on photosynthetic carbon assimilation NaHCO 3- -dependent O 2 evolution and respiration O 2 uptake was monitored in mesophyll protoplasts under light.

Several reports proposed that the AOX pathway maintains electron flow during cold conditions to alleviate the cellular reactive oxygen species ROS; Purvis et al. Since the AOX mutants of pea are not available, studies using Arabidopsis are required to further understand the underlying a mechanisms.


The activity of GR decreased under 1. Water stress inhibits plant photosynthesis by decreasing coupling factor and ATP.

Is the maintenance of homeostatic mitochondrial signaling during stress a physiological role for alternative oxidase? Leaf respiration and alternative oxidase in field-grown alpine grasses respond to natural changes in temperature and light.

Increased respiratory restriction during phosphate-limited growth in transgenic tobacco cells lacking alternative oxidase. The most recent study on diatoms using metabolic inhibitors AA and SHAM as well as knockouts of AOX also demonstrated that the export of reducing power generated in the plastid to mitochondria and the import of mitochondrial ATP into plastid is mandatory for optimized carbon fixation and their growth Bailleul et al.

Mesophyll protoplasts can be used as an excellent model system over whole plants, leaves or leaf discs to study beneficial interactions between chloroplasts and mitochondria for the following reasons: To fully activate the enzyme, supernatant 2.

The changes in SOD activities were marginal in presence of both stresses examined. Reactive oxygen species as signals that modulate plant stress responses and programmed cell death. 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 cia click of a button.

Cleavage of structural proteins during the assembly of the head 815885 bacteriophage T4.

Physiology and Metabolismeds R. The studies of Tezara et al.