Extracellular ascorbic acid and enzyme activities related to ascorbic acid metabolism in Sedum album L. leaves after ozone exposure

Castillo, Federico; Greppin, Hubert

doi:10.1016/0098-8472(88)90033-0

Cited by 230 publications

(136 citation statements)

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“…Ascorbic acid (AA) in the extracellular space reacts rapidly with O $ and its derivatives in aqueous phase (Chameides, 1989 ;Luwe et al, 1993 ;Smirnoff, 1996). Continuous efflux of AA from the cytosol to the apoplast was found in studies of many species (Castillo & Greppin, 1988 ;Luwe et al, 1993 ;Luwe, 1996) and a rapid decrease of AA in the apoplast is evidence of a direct reaction between AA and free radicals. Ascorbic acid, glutathione (GSH), and the enzymes ascorbate peroxidase, glutathione reductase and superoxide dismutase are also known antioxidants which scavenge and remove toxic products before cellular damage occurs in the chloroplast (Jablonski & Anderson, 1982 ;Sakaki et al, 1983 ;Halliwell & Gutteridge, 1989).…”

Section: mentioning

confidence: 99%

“…After O $ enters the leaf through the stomata, it diffuses in the cell wall region and changes to several toxic intermediates such as superoxide anion, hydroxyl radical, hydrogen peroxide, and lipid peroxide (Castillo & Greppin, 1988 ;Badiani, 1990 ;Ranieri et al, 1996). Ascorbic acid (AA) in the extracellular space reacts rapidly with O $ and its derivatives in aqueous phase (Chameides, 1989 ;Luwe et al, 1993 ;Smirnoff, 1996).…”

Section: mentioning

confidence: 99%

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The response of sensitive and tolerant clones of Populus tremuloides to dynamic ozone exposure under controlled environmental conditions

Yun

Laurence

1999

New Phytologist

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Both sensitive and tolerant clones of aspen (Populus tremuloides) were exposed to ozone using four different exposure regimes under controlled environmental conditions. Based on data on ambient ozone from 10 cities in the USA, three treatments of 4-wk exposure to the same SUM06 (an accumulation of hourly O $ concentrations greater than 0.06 ml l −" ) were constructed. The regimes allowed us to investigate : (a) the importance of long (3 wk, treatment 1) versus short (1 wk, treatment 2) duration of regimes with high peaks ; (b) the effect of treatments with variable peak occurrence (treatments 1 and 2) versus uniform peak occurrence (treatment 3) during the exposure period. Nonfumigated control plants were maintained at ozone concentrations 10 nl l −" . Bifacial black necrosis, a typical symptom of ozone injury on aspen leaves, occurred on both clones after 2 wk exposure. Up to 60 % of the leaves on the sensitive clone were injured, with an average of 6 % of total leaf area injured. In the tolerant clone only 10 % of the leaves were injured, with less than 1 % of the total leaf area symptomatic. The severity of injury was consistently greatest in treatment 2, followed by treatments 1 and 3, respectively. The interval between peak exposures was less important than the occurrence of peaks versus a stable maximum concentration. Premature leaf abscission occurred in the sensitive clone. Measures of gas exchange demonstrated reduced photosynthesis under ozone fumigation, but exposure regime was not a significant factor. Concentrations of two antioxidants, ascorbic acid and glutathione, were almost always greater in the resistant than in the sensitive clone, but the differences were not statistically significant. The levels of these antioxidants in aspen leaves did not change with ozone fumigation or leaf age.

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Section: mentioning

confidence: 99%

Section: mentioning

confidence: 99%

The response of sensitive and tolerant clones of Populus tremuloides to dynamic ozone exposure under controlled environmental conditions

Yun

Laurence

1999

New Phytologist

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“…There are reports that O $ stimulates AA in coniferous trees (Bermadinger et al, 1990) and decreases AA in bean plants (Guri, 1983) and spinach (Tanaka et al, 1985) ; however, others have reported that O $ does not change the level of AA (Bender et al, 1994 ;Brunschon-Harti et al, 1995). Castillo & Greppin (1988) reported that total AA in the leaves of Sedum album exposed to O $ is 20% less than that in control plants ; however, the O $ fumigation was at extremely high (200, 400 or 600 nl l −" ) concentrations. A clonal difference in antioxidant level could not be demonstrated in this experiment.…”

Section: The Role Of Antioxidants In Plant Responsementioning

confidence: 99%

The response of clones of Populus tremuloides differing in sensitivity to ozone in the field

Yun

Laurence

1999

New Phytologist

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Ozone (O $ )-sensitive and tolerant clones of aspen (Populus tremuloides) were exposed to O $ at 1n0, 1n7 and 3n0 times the concentration in ambient air at Ithaca, NY, USA (i1n0, i1n7 and i3n0) for 3 months. Visible foliar injury occurred within a few days of the initiation of treatments and developed continuously in i1n7 and i3n0 treatments. Leaf senescence began earlier in trees exposed to greater-than-ambient treatments. Gas-exchange variables were measured five times over the growing season. Net photosynthesis was progressively decreased and finally reduced by 40 and 70% on tolerant and sensitive clones, respectively, but stomatal conductance was not affected by the O $ treatments. As stomatal conductance (g s ) values did not differ in the two types of aspen, we conclude that this is not the defense mechanism to O $ in aspen. At the end of the season, dry weight was reduced by up to 55 and 35% in sensitive and tolerant clones, respectively. Ozone effects were significant and linear on foliar injury, biomass and growth variables such as height, diameter of stem and total leaf area. The levels of two antioxidants, ascorbic acid and glutathione, were investigated to determine if a clonal difference occurred. Concentrations of the free-radical scavengers did not differ in the clones, nor did they seem to be induced by O $ . A cumulative O $ index, SUM06 (the sum of the total µl l −" of exposure when the O $ concentration exceeded 0n06 µl l −" ), was highly correlated with most foliar injury variables and gas-exchange variables except g s in higher O $ treatments. The reduction of carbon gain due to O $ is discussed with regard to foliar damage and biomass decrease.

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“…The mixture was diluted with distilled H,O to give a final concentration of 2% m-phosphoric acid and was centrifuged at 12,OOOg for 10 min. ASC in the supernatant was determined immediately by HPLC, as described by Castillo and Greppin (1988). DHA was separated from ASC by incubating the samples for 24 h at room temperature with 1 mM DTT (final concentration).…”

Section: Determination Of Total Glutathione and Total Ascorbatementioning

confidence: 99%

Evidence for the Presence of the Ascorbate-Glutathione Cycle in Mitochondria and Peroxisomes of Pea Leaves

et al. 1997

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l h e presence of the enzymes of the ascorbate-glutathione cycle was investigated in mitochondria and peroxisomes purified from pea (Pisum sativum L.) leaves. AI1 four enzymes, ascorbate peroxidase (APX; EC 1.1 1.1.1 l ) , monodehydroascorbate reductase (EC 1.6.5.4), dehydroascorbate reductase (EC 1.8.5.1), and glutathione reductase (EC 1.6.4.2), were present in mitochondria and peroxisomes, as well as i n the antioxidants ascorbate and glutathione. l h e activity of the ascorbate-glutathione cycle enzymes was higher in mitochondria than in peroxisomes, except for APX, which was more active in peroxisomes than in mitochondria. lntact mitochondria and peroxisomes had no latent APX activity, and this remained i n the membrane fraction after solubilization assays with 0.2 M KCI.Monodehydroascorbate reductase was highly latent in intact mitochondria and peroxisomes and was membrane-bound, suggesting that the electron acceptor and donor sites of this redox protein are not on the externa1 side of the mitochondrial and peroxisomal membranes. Dehydroascorbate reductase was found mainly in the soluble peroxisomal and mitochondrial fractions. Clutathione reductase had a high latency in mitochondria and peroxisomes and was present i n the soluble fractions of both organelles. I n intact peroxisomes and mitochondria, the presence of reduced ascorbate and glutathione and the oxidized forms of ascorbate and glutathione were demonstrated by high-performance liquid chromatography analysis. l h e ascorbate-glutathione cycle of mitochondria and peroxisomes could represent an important antioxidant protection system against H,O, generated in both plant organelles.

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Extracellular ascorbic acid and enzyme activities related to ascorbic acid metabolism in Sedum album L. leaves after ozone exposure

Cited by 230 publications

References 21 publications

The response of sensitive and tolerant clones of Populus tremuloides to dynamic ozone exposure under controlled environmental conditions

The response of sensitive and tolerant clones of Populus tremuloides to dynamic ozone exposure under controlled environmental conditions

The response of clones of Populus tremuloides differing in sensitivity to ozone in the field

Evidence for the Presence of the Ascorbate-Glutathione Cycle in Mitochondria and Peroxisomes of Pea Leaves

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