Localization of the Gene Coding for a 26-kDa Mitochondrial Protein Detected in Low Temperature-Stored Potato Tubers

1996 ◽  
Vol 147 (6) ◽  
pp. 755-758 ◽  
Author(s):  
Yannis Gounaris
Keyword(s):  
Low Temperature ◽  
Mitochondrial Protein ◽  
Potato Tubers ◽  
Gene Coding

scholarly journals Activity of alternative oxidase and plant uncoupling mitochondrial protein in potato tubers stored at low temperature or submitted to artificial aging

2004 ◽  
Vol 16 (2) ◽  
pp. 69-76 ◽  
Author(s):  
Hugo Alves Pinheiro ◽  
Regis Borges ◽  
Marco Aurélio Pedron e Silva ◽  
Danilo Cruz Centeno
Keyword(s):  
Low Temperature ◽  
Artificial Aging ◽  
Alternative Oxidase ◽  
Cell Damage ◽  
Solanum Tuberosum L ◽  
Mitochondrial Protein ◽  
Respiratory Control ◽  
Protective Mechanism ◽  
Potato Tubers ◽  
Mitochondrial Oxidative Stress

Potato tubers (Solanum tuberosum L. cv. Binje) were stored at 18 and 4ºC in order to verify changes in mitochondrial metabolism, especially in the activities of the alternative oxidase (AOX) and plant uncoupling mitochondria protein (PUMP). Tubers were also sliced and submitted to artificial aging. The oxygen consumption rate (OCR), respiratory control (RC) and ADP/O ratio for mitochondria obtained after storage at 18ºC were not altered, regardless of the time of storage. Considerable increment in OCR, for both respiratory states 3 and 4, was observed after storing the tubers for five and ten days at 4ºC; and it was accomplished by reductions in RC and ADP/O. The AOX activity was evident after five days at 4ºC, and it was enhanced after ten days of storage at that temperature. No significant changes in PUMP activities were observed after one day at 18ºC or at 4ºC, neither after artificial aging. However, increased swelling of potato mitochondria was observed in the presence of valinomycin and linoleic acid when the tubers were kept at 4ºC for five and ten days. Besides the changes in AOX and PUMP activities, slight alterations in ascorbate peroxidase (APX) and catalase (CAT) activities were observed after storing the tubers at 4ºC for 5 days. The activities of these enzymes were higher after storage at 4ºC for 10 days. The results suggest the combined effect of low temperature and time of exposure in promoting AOX activity, probably as a protective mechanism against cell damage in response to mitochondrial oxidative stress.

scholarly journals Effect of Mechanical Injury and Low Temperature Storage on the Accumulation of Glycoalkaloids in the Tubers of 7 Varieties of Potato (Solanum Tuberosum L.) grown in Oman

2003 ◽  
Vol 8 (2) ◽  
pp. 83
Author(s):  
Elsadig A. Eltayeb ◽  
Sana Salem Al-Sinani ◽  
I. A. Khan
Keyword(s):  
Low Temperature ◽  
Solanum Tuberosum L ◽  
Storage Period ◽  
Mechanical Injury ◽  
Potato Tubers ◽  
Low Temperature Storage ◽  
Glycoalkaloid Content ◽  
And Storage ◽  
Safety Limit ◽  
Temperature Storage

Tubers from 7 potato varieties were analyzed for their rates of glycoalkaloid accumulation in response to stresses of three types of mechanical injury and low temperature storage. Mechanical injuries were found to greatly stimulate glycoalkaloid accumulation in both peel and flesh of tubers. The extent of glycoalkaloid accumulation appears to depend on variety, type of mechanical injury, and storage period. Most of the injury-stimulated glycoalkaloid accumulation occurred within 7 and 14 days after treatment. Cutting the tubers resulted in the highest content of glycoalkaloids both in flesh and peel up to levels that exceeded the upper safety limit of 200 mg/kg FW. Injury stimulated α-solanine accumulation in stored potato tubers is more than α-chaconine, resulting in a decrease in the α-chaconine: α-solanine ratio. When tubers were stored at low temperature, the rate of glycoalkaloid accumulation was found to be independent of the glycoalkaloid level at harvest. The greatest increase in total glycoalkaloid content of the seven varieties was found after two weeks of storage at both 4 ºC and 10 ºC. Further storage at these temperatures resulted in a decrease in the rate of glycoalkaloid accumulation in most of them. At 10 ºC glycoalkaloid content tended to increase more rapidly than at 4 ºC. The α-solanine content of the tubers showed an increase following low temperature storage.  

scholarly journals 472 Effects of Low-temperature Storage on Carbohydrate Metabolism in Potato Tubers

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 526B-526 ◽  
Author(s):  
Robert W. Blenkinsop ◽  
Leslie J. Copp ◽  
Alejandro G. Marangoni ◽  
Rickey Y. Yada
Keyword(s):  
Low Temperature ◽  
Metabolic Rate ◽  
Carbohydrate Metabolism ◽  
Potato Chip ◽  
Anaerobic Respiration ◽  
Pentose Phosphate ◽  
Potato Tubers ◽  
Low Temperature Storage ◽  
C Storage ◽  
Phosphofructokinase Activity

Following exposure to low temperatures (i.e., <10 °C), potato tubers undergo low-temperature sweetening (LTS), the conversion of starch to sugars. This phenomenon is of great importance to potato chip processors because high levels of reducing sugars lead to undesirable nonenzymatic browning during potato chip frying operations. The purpose of this study was to elucidate the biochemical differences in carbohydrate metabolism between a tolerant (ND 860-2) and a sensitive (Novachip) cultivar during 4 °C storage. On chilling, there was an increase in the levels of sucrose, fructose, and glucose in both cultivars, with levels being at least 2-fold higher in the sensitive cultivar. Increased levels of ATP and NADH, along with a higher respiratory rate observed in the tolerant tubers, collectively indicate a higher metabolic rate in the LTS-tolerant cultivar. ATP- and pyrophosphate-dependent phosphofructokinase activity was similar in both cultivars. Higher levels of ethanol and lactate were also observed in ND 860-2, suggesting a greater flux of sugars via anaerobic respiration. No significant differences were observed in enzymatic activities in the oxidative pentose phosphate pathway (PPP) or in levels of NADPH, thereby suggesting that the PPP does not play a role in conferring LTS tolerance. Therefore, we propose that LTS-tolerant potatoes may maintain low tissue sugar concentrations via an overall increased metabolism, rather than differing in one specific metabolic step. This increased metabolic rate does not appear to be due to greater enzyme expression (i.e., coarse control) but, rather, to a greater overall flux of carbohydrates through glycolysis and respiration.

scholarly journals Impaired expression of genes coding for reactive oxygen species scavenging enzymes in testes of Mtfr1/Chppr-deficient mice

Reproduction ◽  
2007 ◽  
Vol 134 (3) ◽  
pp. 483-492 ◽  
Author(s):  
Massimiliano Monticone ◽  
Laura Tonachini ◽  
Sara Tavella ◽  
Paolo Degan ◽  
Roberta Biticchi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Oxidative Dna Damage ◽  
Mitochondrial Protein ◽  
Nuclear Gene ◽  
Cell Types ◽  
Expression Of Genes ◽  
Gene Coding ◽  
Scavenging Enzymes ◽  
Deficient Mice

Mtfr1/Chppris a nuclear gene coding for a mitochondrial protein capable of inducing fission of this organelle in a sequence-specific manner. Here we show that in mice,Mtfr1/Chppris ubiquitously expressed and displays the highest level of expression in pubertal and adult testes and in particular in spermatids and Leydig cells. To investigateMtfr1functionin vivo, we analyzed homozygous mice null for this gene obtained through a gene trap approach. We show that these mice fail to expressMtfr1and that in their testes several genes coding for enzymes involved in the defense against oxidative stress are downregulated. Among these, we studied in particular glutathione peroxidase 3 and show its expression in selected testis cell types. Furthermore, we demonstrate oxidative DNA damage specifically in testes ofMtfr1-deficient mice likely resulting from a reduced antioxidant activity. As a whole, these data suggest thatMtfr1protects the male gonads against oxidative stress.

scholarly journals S. cerevisiae Strain Lacking Mitochondrial IF3 Shows Increased Levels of Tma19p during Adaptation to Respiratory Growth

Cells ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 645 ◽  
Author(s):  
Levitskii ◽  
Baleva ◽  
Chicherin ◽  
Krasheninnikov ◽  
Kamenski
Keyword(s):  
Mitochondrial Protein ◽  
Carbon Sources ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Mitochondrial Translation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Gene Coding ◽  
Slow Adaptation ◽  
Respiratory Growth ◽  
Translation Initiation Factor 3

After billions of years of evolution, mitochondrion retains its own genome, which gets expressed in mitochondrial matrix. Mitochondrial translation machinery rather differs from modern bacterial and eukaryotic cytosolic systems. Any disturbance in mitochondrial translation drastically impairs mitochondrial function. In budding yeast Saccharomyces cerevisiae, deletion of the gene coding for mitochondrial translation initiation factor 3 - AIM23, leads to an imbalance in mitochondrial protein synthesis and significantly delays growth after shifting from fermentable to non-fermentable carbon sources. Molecular mechanism underlying this adaptation to respiratory growth was unknown. Here, we demonstrate that slow adaptation from glycolysis to respiration in the absence of Aim23p is accompanied by a gradual increase of cytochrome c oxidase activity and by increased levels of Tma19p protein, which protects mitochondria from oxidative stress.

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