scholarly journals The Alternative Oxidase of Plant Mitochondria Is Involved in the Acclimation of Shoot Growth at Low Temperature. A Study of Arabidopsis AOX1a Transgenic Plants

2005 ◽  
Vol 139 (4) ◽  
pp. 1795-1805 ◽  
Author(s):  
Fabio Fiorani ◽  
Ann L. Umbach ◽  
James N. Siedow
2001 ◽  
Vol 48 (3) ◽  
pp. 729-737 ◽  
Author(s):  
W Jarmuszkiewicz ◽  
O Fraczyk ◽  
L Hryniewiecka

Mitochondria of amoeba Acanthamoeba castellanii in addition to the conventional cytochrome pathway possess, like plant mitochondria, a cyanide-resistant alternative quinol oxidase. In mitochondria isolated from amoeba batch culture grown temporarily at low temperature (6 degrees C), higher respiration was accompanied by lower coupling parameters as compared to control culture (grown at 28 degrees C). In the presence of benzohydroxamate, respiratory rates and coupling parameters were similar in both types of mitochondria indicating that growth in cold conditions did not disturb the cytochrome pathway. Increased contribution of alternative oxidase in total mitochondrial respiration in low-temperature-grown amoeba cells was confirmed by calculation of its contribution using ADP/O measurements. Furthermore, in mitochondria from low-temperature- grown cells the content of the alternative oxidase was increased and correlated with the increase in the unstimulated and GMP-stimulated cyanide-resistant respiratory activity. A possible physiological role of higher activity of alternative oxidase as response to growth at a low temperature in unicellular organisms, such as amoeba, is discussed.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jie Dong ◽  
Lei Cao ◽  
Xiaoying Zhang ◽  
Wuhua Zhang ◽  
Tao Yang ◽  
...  

A sudden cooling in the early spring or late autumn negatively impacts the plant growth and development. Although a number of studies have characterized the role of the transcription factors (TFs) of plant R2R3-myeloblastosis (R2R3-MYB) in response to biotic and abiotic stress, plant growth, and primary and specific metabolisms, much less is known about their role in Rosa multiflora under chilling stress. In the present study, RmMYB108, which encodes a nuclear-localized R2R3-MYB TF with a self-activation activity, was identified based on the earlier published RNA-seq data of R. multiflora plants exposed to short-term low-temperature stress and also on the results of prediction of the gene function referring Arabidopsis. The RmMYB108 gene was induced by stress due to chilling, salt, and drought and was expressed in higher levels in the roots than in the leaves. The heterologous expression of RmMYB108 in Arabidopsis thaliana significantly enhanced the tolerance of transgenic plants to freezing, water deficit, and high salinity, enabling higher survival and growth rates, earlier flowering and silique formation, and better seed quantity and quality compared with the wild-type (WT) plants. When exposed to a continuous low-temperature stress at 4°C, transgenic Arabidopsis lines–overexpressing RmMYB108 showed higher activities of superoxide dismutase and peroxidase, lower relative conductivity, and lower malondialdehyde content than the WT. Moreover, the initial fluorescence (Fo) and maximum photosynthetic efficiency of photosystem II (Fv/Fm) changed more dramatically in the WT than in transgenic plants. Furthermore, the expression levels of cold-related genes involved in the ICE1 (Inducer of CBF expression 1)-CBFs (C-repeat binding factors)-CORs (Cold regulated genes) cascade were higher in the overexpression lines than in the WT. These results suggest that RmMYB108 was positively involved in the tolerance responses when R. multiflora was exposed to challenges against cold, freeze, salt, or drought and improved the cold tolerance of transgenic Arabidopsis by reducing plant damage and promoting plant growth.


2001 ◽  
Vol 21 (3) ◽  
pp. 369-379 ◽  
Author(s):  
Vasily N. Popov ◽  
Albert C. Purvis ◽  
Vladimir P. Skulachev ◽  
Anneke M. Wagner

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.


Biomics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 360-367
Author(s):  
B.R. Kuluev ◽  
Kh.G. Musin ◽  
E.A. Baimuhametova

The trolC gene refers to plast genes that have entered the genome of Nicotiana tabacum as a probable result of horizontal transfer from Agrobacterium rhizogenes. It was shown that the trolC gene is expressed in young tissues of wild type tobacco; however, the physiological functions of the product of this gene remain largely unknown. The aim of our work was to obtain transgenic tobacco plants expressing a fragment of the trolC gene under the control of the 35SCaMV promoter in an antisense orientation and to assess the growth parameters of their roots under the action of abiotic stress factors. For morphometric analysis, 8 lines of transgenic plants were used. The analysis of root growth under the action of sodium chloride (100 mM), cadmium acetate (100 μM) and hypothermia (12°C) was conducted. Transgenic plants were characterized by improved shoot growth parameters under normal conditions. The roots of transgenic plants grew more slowly under normal conditions and under the action of cadmium and hypothermia than in wild type plants. The product of trolC gene has a negative effect on shoot growth, a positive effect on root growth, and also participates in the regulation and maintenance of root growth under the action of cadmium and hypothermia.


2019 ◽  
Vol 60 (12) ◽  
pp. 2744-2757 ◽  
Author(s):  
Sung Mi Cho ◽  
Sanghee Kim ◽  
Hojin Cho ◽  
Hyoungseok Lee ◽  
Jun Hyuck Lee ◽  
...  

Abstract Microalgal ice-binding proteins (IBPs) in the polar region are poorly understood at the genome-wide level, although they are important for cold adaptation. Through the transcriptome study with the Arctic green alga Chloromonas sp. KNF0032, we identified six Chloromonas IBP genes (CmIBPs), homologous with the previously reported IBPs from Antarctic snow alga CCMP681 and Antarctic Chloromonas sp. They were organized with multiple exon/intron structures and low-temperature-responsive cis-elements in their promoters and abundantly expressed at low temperature. The biological functions of three representative CmIBPs (CmIBP1, CmIBP2 and CmIBP3) were tested using in vitro analysis and transgenic plant system. CmIBP1 had the most effective ice recrystallization inhibition (IRI) activities in both in vitro and transgenic plants, and CmIBP2 and CmIBP3 had followed. All transgenic plants grown under nonacclimated condition were freezing tolerant, and especially 35S::CmIBP1 plants were most effective. After cold acclimation, only 35S::CmIBP2 plants showed slightly increased freezing tolerance. Structurally, the CmIBPs were predicted to have β-solenoid forms with parallel β-sheets and repeated TXT motifs. The repeated TXT structure of CmIBPs appears similar to the AidA domain-containing adhesin-like proteins from methanogens. We have shown that the AidA domain has IRI activity as CmIBPs and phylogenetic analysis also supported that the AidA domains are monophyletic with ice-binding domain of CmIBPs, and these results suggest that CmIBPs are a type of modified adhesins.


2014 ◽  
Vol 94 (6) ◽  
pp. 1091-1101 ◽  
Author(s):  
Jia Wang ◽  
Melissa Cheung ◽  
Lara Rasooli ◽  
Sasan Amirsadeghi ◽  
Greg C. Vanlerberghe

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.


2019 ◽  
Vol 70 (17) ◽  
pp. 4345-4354 ◽  
Author(s):  
Aprajita Kumari ◽  
Pradeep Kumar Pathak ◽  
Mallesham Bulle ◽  
Abir U Igamberdiev ◽  
Kapuganti Jagadis Gupta

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.


1992 ◽  
Vol 20 (2) ◽  
pp. 361-363 ◽  
Author(s):  
Anthony L. Moore ◽  
James N. Siedow

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