The nature and regulation of the alternative oxidase of plant mitochondria

Anthony L. Moore; James N. Siedow

doi:10.1042/bst0200361

Stress-Induced Changes in Ubiquinone Concentration and Alternative Oxidase in Plant Mitochondria

Bioscience Reports ◽

10.1023/a:1013246501917 ◽

2001 ◽

Vol 21 (3) ◽

pp. 369-379 ◽

Cited By ~ 23

Author(s):

Vasily N. Popov ◽

Albert C. Purvis ◽

Vladimir P. Skulachev ◽

Anneke M. Wagner

Keyword(s):

Alternative Oxidase ◽

Respiratory Activity ◽

Plant Mitochondria ◽

High Oxygen ◽

Plant Tissues ◽

Respiration Rates ◽

Bell Peppers ◽

Respiration Of Mitochondria ◽

Induced Changes

We have investigated the influence of stress conditions such as incubation at 4°C and incubation in hyperoxygen atmosphere, on plant tissues. The ubiquinone (Q) content and respiratory activity of purified mitochondria was studied. The rate of respiration of mitochondria isolated from cold-treated green bell peppers (Capsicum annuum L) exceeds that of controls, but this is not so for mitochondria isolated from cold-treated cauliflower (Brassica oleracea L). Treatment with high oxygen does not alter respiration rates of cauliflower mitochondria. Analysis of kinetic data relating oxygen uptake with Q reduction in mitochondria isolated from tissue incubated at 4°C (bell peppers and cauliflowers) and at high oxygen levels (cauliflowers) reveals an increase in the total amount of Q and in the percentage of inoxidizable QH2. The effects are not invariably accompanied by an induction of the alternative oxidase (AOX). In those mitochondria where the AOX is induced (cold-treated bell pepper and cauliflower treated with high oxygen) superoxide production is lower than in the control. The role of reduced Q accumulation and AOX induction in the defense against oxidative damage is discussed.

Download Full-text

Role of the alternative oxidase in limiting superoxide production by plant mitochondria

Physiologia Plantarum ◽

10.1111/j.1399-3054.1997.tb03468.x ◽

1997 ◽

Vol 100 (1) ◽

pp. 165-170 ◽

Cited By ~ 148

Author(s):

Albert C. Purvis

Keyword(s):

Alternative Oxidase ◽

Plant Mitochondria ◽

Superoxide Production

Download Full-text

Plant respiration in a high CO2 world: How will alternative oxidase respond to future atmospheric and climatic conditions?

Canadian Journal of Plant Science ◽

10.4141/cjps2013-176 ◽

2014 ◽

Vol 94 (6) ◽

pp. 1091-1101 ◽

Cited By ~ 6

Author(s):

Jia Wang ◽

Melissa Cheung ◽

Lara Rasooli ◽

Sasan Amirsadeghi ◽

Greg C. Vanlerberghe

Keyword(s):

Climate Change ◽

Water Availability ◽

Alternative Oxidase ◽

Climatic Factors ◽

Plant Mitochondria ◽

Climatic Conditions ◽

Carbon Gain ◽

Energy Yield ◽

Combined Processes ◽

Plant Respiration

Wang, J., Cheung, M., Rasooli, L., Amirsadeghi, S. and Vanlerberghe, G. C. 2014. Plant respiration in a high CO2 world: How will alternative oxidase respond to future atmospheric and climatic conditions? Can. J. Plant Sci. 94: 1091–1101. Plant mitochondria contain an alternative oxidase (AOX) that reduces the energy yield of respiration. While respiration and photosynthesis are known to interact, the role of AOX in the light remains poorly understood. This gap in our understanding of leaf metabolism extends to future conditions of high CO2 and climate change. While studies indicate that AOX respiration is quite responsive to growth conditions, few studies have examined AOX respiration at high CO2 and little is known regarding the combined impact of changes in both CO2 and other climatic factors such as temperature and water availability. Given its non-energy conserving nature, a fundamental response by AOX to these future conditions could impact the net carbon gain that results from the combined processes of photosynthesis and respiration. Here, we show that leaf AOX protein amount in Nicotiana tabacum is dependent upon growth irradiance and CO2 level, that AOX is subject to biochemical control by intermediates of photorespiration, and that photosynthesis is impacted in transgenic plants lacking AOX. We also review findings that tobacco AOX respiration is responsive to climatic variables (temperature, water availability), thus providing an excellent experimental system to investigate the interplay between AOX, photosynthesis at high CO2, and climate change.

Download Full-text

Alternative oxidase is an important player in the regulation of nitric oxide levels under normoxic and hypoxic conditions in plants

Journal of Experimental Botany ◽

10.1093/jxb/erz160 ◽

2019 ◽

Vol 70 (17) ◽

pp. 4345-4354 ◽

Cited By ~ 13

Author(s):

Aprajita Kumari ◽

Pradeep Kumar Pathak ◽

Mallesham Bulle ◽

Abir U Igamberdiev ◽

Kapuganti Jagadis Gupta

Keyword(s):

Nitric Oxide ◽

Alternative Oxidase ◽

Plant Mitochondria ◽

No Production ◽

Complex Iv ◽

Increase Energy Efficiency ◽

Hypoxic Conditions ◽

Cytochrome Pathway ◽

Important Player ◽

Elicitor Treatments

Abstract Plant mitochondria possess two different pathways for electron transport from ubiquinol: the cytochrome pathway and the alternative oxidase (AOX) pathway. The AOX pathway plays an important role in stress tolerance and is induced by various metabolites and signals. Previously, several lines of evidence indicated that the AOX pathway prevents overproduction of superoxide and other reactive oxygen species. More recent evidence suggests that AOX also plays a role in regulation of nitric oxide (NO) production and signalling. The AOX pathway is induced under low phosphate, hypoxia, pathogen infections, and elicitor treatments. The induction of AOX under aerobic conditions in response to various stresses can reduce electron transfer through complexes III and IV and thus prevents the leakage of electrons to nitrite and the subsequent accumulation of NO. Excess NO under various stresses can inhibit complex IV; thus, the AOX pathway minimizes nitrite-dependent NO synthesis that would arise from enhanced electron leakage in the cytochrome pathway. By preventing NO generation, AOX can reduce peroxynitrite formation and tyrosine nitration. In contrast to its function under normoxia, AOX has a specific role under hypoxia, where AOX can facilitate nitrite-dependent NO production. This reaction drives the phytoglobin–NO cycle to increase energy efficiency under hypoxia.

Download Full-text