Oxidative and Phosphorylative Activities of Mitochondria Isolated from Pea Root Tissues

Childress, Charles C.; Stein, Howard J.

doi:10.1104/pp.40.4.752

Cited by 6 publications

(3 citation statements)

References 14 publications

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“…(w/v) BSA concentration with mitochondria from glandless cotton. No oxidative phosphorylation was observed with glanded 4's were similar. The ADP :O ratios for soybean mitochondria were close to 60 % of the theoretical value compared to 40 % of the theoretical valtue for cotton mitochondria.…”

Section: Resultsmentioning

confidence: 88%

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Oxidative and Phosphorylative Activities of Mitochondria Isolated From Cotton Hypocotyls

1968

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Abstract. Mitochondria isolated from 2 strains of cotton plant hypocotyls (Gossypium hirsutum L. var. Rex smootlh leaf and Rex glandless) were examined for their oxidative phosphorylation activities. Bovine serum albumin at a relatively high concentration was essential in the extraction medium for the isolation of oxidatively active mitochondria from both strains of cotton. Phosphorylation was obtained only with Rex glandless cotton mitochondria. This activity was low in comparison to the mitochondria isolated from soybeans (Glycine max L. var. Lee). The endogenous gossypol content was found to be much higher in the Rex smooth leaf tissue than in the Rex glandless tissue. In turn, comparable gossypol differences were found associated with their respective mitochondrial fractions. Exogenous gossypol uncoupled succinate oxidation with active mitochondria isolated from soybeans. Gossypol as a possible uncoupler is discussed and compared to carbonyl cyanide, m-chlorophenvl hydrazone and 2,4-dinitrophenol.Metabolically active mitochondria have been isolated and studied in a xvide variety of plant tissues (7), but verv little xvork has been reported on cotton mitochonclria. Throneherry (13) reported that an extract fromii cotton tissue inactivatedc mitochondria prepared fromii sovbean seedlin,gs. He showed that the inclusion of bovine serum albumin (BSA) in the extractioni medium facilitated the isolation of active mitochondria from cotton hypocotyls. Later, Throneberry (14) found that the phosphorylation mechanism was probably more sensitive to endogenous inhibitors than were the oxidative enzymnes. Plants of the genus Gossvpium, of which cotton is a member, normally containi several pigments unique to the plant kingdom. Some of the pigments are enclosed in glands that are distribuited throughout the above ground part of some strains of cotton. An important component of the glands is gossypol (1.1 ', 6,6',7,7'-hexah. droxy-3,3' -dimethvl-15,5' -diisopropvl-2,2' -binaphthyl-8,8'-dialdehyde), a polyphenolic. toxic, velloNv compound (2). MAvers and Throneherrv (9) reported that gossylpol affected mitochondria prepared from sweet potato and beef heart tissuies. Gossypol was showvn to inhibit oxidative phosphorylation at concentrations which had no effect on oxidation. This prompted the investigation of a glandless strain of cotton. relatively free of gossypol. Rex glan(dless, hereafter referred to as glanded and glandless, respectively) and soybeans (Glycine mlax L. var. Lee) were used as the experimental material. The seeds were surface sterilized with 0.5 % (w/v) sodium hvpochlorite. After rinsing thoroughly, the seeds wvere germinated in paper towels, moistened w\ith n0.1 mAi CaCI.., at '0O in the dark. Five-dav old hypocotyls were harvested, cut into 3 to 5 cm segments, and chilled at 0 .A slight modification of the Bonner and Sikes procedure (1) was used for mitochondria isolation.The hypocotyl segments were disrupted in a WaringBlendor at a reduced speed using a volume of extraction medium equal to the weiglht of ...

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Section: Resultsmentioning

confidence: 88%

“…On the basis of previous reports (4,10,13) that the inclusion of BSA in either the reaction mixture or the extraction medium improved the metabolic activity of plant mitochondria, the effect of BSA in the extraction medium on the activitv of cotton hypocotyl mitochondria was investigated.…”

Section: Resultsmentioning

confidence: 99%

Oxidative and Phosphorylative Activities of Mitochondria Isolated From Cotton Hypocotyls

1968

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“…The reduction in second state 3 oxidation by oligomycin was not overcome by further addition of ADP but was reversed by DNP. This uncoupling response probably occurs as a result of interference of phosphorylation by oligomycin(5).Prometryne causes a similar reduction in second state 3 oxidation of both succinate and _malate(Figure 3).18 Polarograph traces of the reduction of state 3 oxidation of succinate and malate by oligomycin and its reversal by DNP. Mitochondrial nitrogen concentration was 48 J-tg for malate and 45 J-tg for succinate.…”

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confidence: 94%

Soybean Mitochondrial Response to Prometryne and Fluometuron

McDaniel

Frans

1969

Weed sci.

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Experiments were conducted to determine the effect of 3-(m-trifluoromethylphenyl)-1,1-dimethylurea (fluometuron) and 2,4-bis(isopropylamino)-6-methylmercapto-s-triazine (prometryne) on oxygen consumption by mitochondria isolated from the hypocotyls of soybean (Glycine max L., var. Lee) seedlings. Prometryne caused a decrease in second state 3 oxidation of both malate and succinate, but the decrease was overcome by 2,4-dinitrophenol (hereinafter referred to as DNP), indicating a response similar to that of oligomycin. Fluometuron caused an increase in second state 4 oxidation of both malate and succinate and overcame the inhibition of oxidative phosphorylation caused by oligomycin, indicating an uncoupling response similar to DNP. Fluometuron was also shown to reverse the inhibition of oxidative phosphorylation caused by prometryne. Concentrations of prometryne causing the 50% inhibitory response were somewhat higher than those reported for s-triazines on other tissues, while those for fluometuron were well within the inhibitory range reported for other substituted ureas.

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Kohlenhydrat- und Säurestoffwechsel

Reznik

1966

Fortschritte Der Botanik

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Oxidative and Phosphorylative Activities of Mitochondria Isolated from Pea Root Tissues

Cited by 6 publications

References 14 publications

Oxidative and Phosphorylative Activities of Mitochondria Isolated From Cotton Hypocotyls

Oxidative and Phosphorylative Activities of Mitochondria Isolated From Cotton Hypocotyls

Soybean Mitochondrial Response to Prometryne and Fluometuron

Kohlenhydrat- und Säurestoffwechsel

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