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1.
The activities of antioxidative enzymes and the concentration of malondialdehyde were assayed in cucumber leaves (Cucumis sativus L.) 0, 6, 12, 24, 48, 72, and 96 h after the cucumber seedlings were infested by Bemisia tabaci (Gennadius). The results indicated that the activities of antioxidative enzymes were increased after herbivore infestation,
including superoxide dismutase (SOD), and peroxidase (POD), and the levels of malondialdehyde (MDA), which is a product of
membrane lipid peroxidation in the leaves. The enzymes and MDA showed peaks of different activity levels at 24 and 48 h after
the infestation. SOD activity reached the highest peak, 10.4% higher than control, at 24 h, POD activity reached the highest
peak, 213.2% higher than control, at 6 h, catalase (CAT) activity was not statistically significant compared with the control,
and MDA content reached the highest peak, 59.9% higher than control, at 48 h. The results suggested that the enhanced activities
of antioxidative enzymes and MDA content may contribute to bioprotection of cucumber plants against B. tabaci infestation.
Handling editor: Henryk Czosnek 相似文献
2.
Effect of d-mannose treatment on different antioxidants, phenolics, protease activity, lipid peroxidation, DNA damage and cell death was investigated in coleoptiles of etiolated wheat seedlings. Modulations in these biochemical parameters were monitored up to 96 h after treatment at 24 h intervals. With accelerating effect on initial signs of cell death, i.e., appearance of long DNA fragmentation and no effect on initiation of terminal stage, i.e., internucleosomal nDNA fragmentation, mannose treatment (1 % = 56 mM) diminished the antioxidant activities in wheat coleoptiles. Mannose treatment decreased the catalase activity at all intervals, while APX and POD activities decreased at 72 h. Peroxidation of lipids increased at 72 h after mannose treatment. Levels of most of antioxidants, i.e., SOD, peroxidases and phenolics were raised during initial time period (24–48 h) of mannose treatment probably as an attempt to counter the stress effect. Protease activity gradually increased and protein content decreased with time in both treated and non-treated coleoptiles. Sharp decrease in CAT, APX and peroxidase activities and increase in lipid peroxidation at 72 h overlaps with apoptotic internucleosomal nDNA fragmentation in this organ. This coincidence points towards the importance of compromised antioxidant defense and involvement of reactive oxygen species in initiation of terminal stage of programmed cell death in wheat coleoptile. In conclusion, accelerating effect on DNA fragmentation and lipid peroxidation along with diminished antioxidant activities at the time of internucleosomal nDNA fragmentation, provide evidence for pro-apoptotic effect of d-mannose in wheat coleoptile. 相似文献
3.
Nickel-induced Inhibition of Wheat Root Growth is Related to H2O2 Production, but not to Lipid Peroxidation 总被引:1,自引:1,他引:0
Effects of exogenous nickel (Ni: 10 and 200 μM) on growth, mitotic activity, Ni accumulation, H2O2 content and lipid peroxidation as well as the activities of various antioxidative enzymes, such as superoxide dismutase (SOD),
catalase (CAT), ascorbate peroxidase (APX) and glutathione peroxidase (GSH-Px) were investigated in wheat roots. A considerable
Ni accumulation in the roots occurred at both the concentrations. Although Ni at 10 μM did not have any significant effect
on root growth, it strongly inhibited the root growth at 200 μM. Mitotic activity in the root tips was not significantly affected
by exposure of the seedlings to 10 μM Ni; however, it was almost completely inhibited at 200 μM treatment. Ni stress did not
result in any significant changes in CAT and APX activities as well as lipid peroxidation. However, H2O2 concentration increased up to 82% over the control in the roots of seedlings exposed to 200 μM Ni. There was a significant
decline in both SOD (50%) and GSH-Px (20–30%) activities in the roots when the seedlings were treated with 200 μM Ni. The
results indicated that a strong inhibition of wheat root growth caused by Ni stress was not due to enhanced lipid peroxidation,
but might be related to the accumulation of H2O2 in root tissue. 相似文献
4.
Effect of drought on chlorophyll content and antioxidant enzyme activities in leaves of three wheat cultivars varying in productivity 总被引:1,自引:0,他引:1
M. K. Nikolaeva S. N. Maevskaya A. G. Shugaev N. G. Bukhov 《Russian Journal of Plant Physiology》2010,57(1):87-95
Seedlings of three wheat varieties (Triticum aestivum L.)—highly productive cv. Ballada, moderately productive cv. Belchanka, and low productive cv. Beltskaya—were exposed to
progressive soil drought (cessation of watering for 3, 5, and 7 days) and then analyzed for chlorophyll content and activities
of ferredoxin-NADP+ oxidoreductase (FNR) and antioxidant enzymes, namely, glutathione reductase (GR) and ascorbate peroxidase (AscP). In addition,
the proline content, and the extent of lipid peroxidation were examined. In the first period of water limitation, the water
loss from leaves was slight for all wheat cultivars, which is characteristic of drought-resistant varieties. After 7-day drought
the leaf water content decreased by 5.2–6.8%. The total chlorophyll content expressed per unit dry weight increased insignificantly
during the first two periods of drought but decreased by 13–15% later on. This decrease was not accompanied by changes in
chlorophyll a/b ratio. The plant dehydration did not induce significant changes in FNR activity. Activities of GR and AscP in leaves of wheat
cultivars Ballada and Belchanka increased on the 3rd and 5th days of drought. Owing to the coordinated increase in GR and
AscP activities, the lipid peroxidation rate remained at nearly the control level observed in water-sufficient plants. When
the dehydration period was prolonged to 7 days, activities of GR and AscP in wheat cultivars reduced in parallel with the
increase in malonic dialdehyde (MDA) content, indicating that the antioxidant enzyme defense system was weakened and lipid
peroxidation enhanced. Unlike Ballada and Belchanka, the wheat cv. Beltskaya did not exhibit the increase in GR and AscP activities
during progressive soil drought. The increase in MDA content by 16% in this cultivar was only observed after a 7-day drought
period. The proline content in leaves of all wheat cultivars increased substantially during drought treatment. Thus, in wheat
cultivars examined, different responses of the defense systems were mobilized to implement plant protection against water
stress. The activities of antioxidant enzyme defense system depended on wheat cultivar, duration of drought, and the stage
of leaf development. 相似文献
5.
Enhanced chilling tolerance at the booting stage in rice by transgenic overexpression of the ascorbate peroxidase gene, OsAPXa 总被引:3,自引:0,他引:3
Low temperatures during the booting stage reduce rice yields by causing cold-induced male sterility. To determine whether
antioxidant capacity affects the ability of rice plants to withstand chilling at the booting stage, we produced transgenic
rice plants that overexpress OsAPXa and have increased APX activity. The effect of increased APX activity on the levels of H2O2 and lipid peroxidation were determined by measuring H2O2 levels and malondialdehyde (MDA) contents in spikelets during cold treatments at the booting stage. The levels of H2O2 and the MDA content increased by 1.5-fold and twofold, respectively in WT plants subjected to a 12°C treatment for 6 days.
In contrast, transgenic lines showed small changes in H2O2 levels and MDA content under cold stress, and H2O2 levels and MDA content were significantly lower than in WT plants. APX activity showed negative correlations with levels
of H2O2 and MDA content, which increased during cold treatment. Cold tolerance at the booting stage in transgenic lines and WT plants
was evaluated. Spikelet fertility was significantly higher in transgenic lines than in WT plants after a 12°C treatment for
6 days. These results indicate that higher APX activity enhances H2O2-scavenging capacity and protects spikelets from lipid peroxidation, thereby increasing spikelet fertility under cold stress. 相似文献
6.
Mediouni Chamseddine Ben Ammar Wided Houlné Guy Chabouté Marie-Edith Jemal Fatma 《Plant Growth Regulation》2009,57(1):89-99
We compare cadmium and copper induced oxidative stress in tomato leaves and the antioxidative enzyme response during a time
course of 96 h. Plants were subjected to 25 μM of CdCl2 or CuSO4 and malondialdehyde (MDA) level and activity of guaiacol peroxidase, superoxide dismutase, catalase, ascorbate peroxidase
and glutathione reductase were determined. The results showed that there was an early increase in the MDA level and in the
guaiacol peroxidase activity more pronounced with copper exposure during almost all the time course of the experiment. The
activity of superoxide dismutase and catalase was induced very early after cadmium and copper treatment, reached a maximal
value after 12 h and then declined but it remained always slightly higher than the control at the end of the experiment. Ascorbate
peroxidase activity pathway was similar to superoxide dismutase or catalase with a maximal activity after 48 h of heavy metal
exposure. Induction of glutathione reductase activity observed only under copper exposure is maintained during almost all
the experimental time. The antioxidative activity developed by tomato leaves is more induced by copper treatment. This can
be related to the ability of this metal to induce more than cadmium an accumulation of reactive oxygen species (ROS) at the
cellular level. Decline in the antioxidative enzymes activity at the end of the experiment can be a consequence of cadmium-
and copper-inducing a further ROS formation that might affect enzymes activity. 相似文献
7.
Flooding-induced membrane damage, lipid oxidation and activated oxygen generation in corn leaves 总被引:19,自引:1,他引:18
Flooding effects on membrane permeability, lipid peroxidation and activated oxygen metabolism in corn (Zea mays L.) leaves were investigated to determine if activated oxygens are involved in corn flooding-injury. Potted corn plants were flooded at the 4-leaf stage in a controlled environment. A 7-day flooding treatment resulted in a significant increase in chlorophyll breakdown, lipid peroxidation (malondialdehye content), membrane permeability, and the production of superoxide (O
2
-
) and hydrogen peroxide (H2O2) in corn leaves. The effects were much greater in older leaves than in younger ones. Spraying leaves with 8-hydroxyquinoline (an O
2
-
scavenger) and sodium benzoate (an .OH scavenger) reduced the oxidative damage and enhanced superoxide dismutase (SOD) activity. A short duration flooding treatment elevated the activities of SOD, catalase, ascorbate peroxidase (AP), and glutathione reductase (GR), while further flooding significantly reduced the enzyme activities but enhanced the concentrations of ascorbic acid and reduced form glutathione (GSH). It was noted that the decline in SOD activity was greater than that in H2O2 scavengers (AP and GR). The results suggested that O
2
-
induced lipid peroxidation and membrane damage, and that excessive accumulation of O
2
-
is due to the reduced activity of SOD under flooding stress. 相似文献
8.
The influence of the arbuscular mycorrhizal (AM) fungus, Glomus mosseae, on characteristics of growth, photosynthetic pigments, osmotic adjustment, membrane lipid peroxidation and activity of antioxidant
enzymes in leaves of tomato (Lycopersicon esculentum cv Zhongzha105) plants was studied in pot culture under low temperature stress. The tomato plants were placed in a sand and
soil mixture at 25°C for 6 weeks, and then subjected to 8°C for 1 week. AM symbiosis decreased malondialdehyde (MDA) content
in leaves. The contents of photosynthetic pigments, sugars and soluble protein in leaves were higher, but leaf proline content
was lower in mycorrhizal than non-mycorrhizal plants. AM colonization increased the activities of superoxide dismutase (SOD),
catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) in leaves. The results indicate that the AM fungus is capable
of alleviating the damage caused by low temperature stress on tomato plants by reducing membrane lipid peroxidation and increasing
the photosynthetic pigments, accumulation of osmotic adjustment compounds, and antioxidant enzyme activity. Consequently,
arbuscular mycorrhiza formation highly enhanced the cold tolerance of tomato plant, which increased host biomass and promoted
plant growth. 相似文献
9.
Photosynthetic rate,chlorophyll fluorescence parameters,and lipid peroxidation of maize leaves as affected by zinc deficiency 总被引:1,自引:0,他引:1
Pot trial in greenhouse was conducted using cumulic cinnamon soil from North China to study the effects of zinc deficiency
on CO2 exchange, chlorophyll fluorescence, the intensity of lipid peroxidation, and the activity of superoxide dismutase (SOD) in
leaves of maize seedlings. Zn deficiency resulted in a reduction of net photosynthetic rate and stomatal conductance to H2O. The maximum quantum efficiency of photosystem 2 (PS2) and the PS2 activity were depressed, while the pool size of the plastoquinone
molecules was not affected by Zn deficiency. The content of super oxygen anion radical (O2
·−) and the intensity of lipid peroxidation as assessed by malonyldialdehyde content in Zn-deficient leaves were higher than
those in Zn-sufficient leaves. The activity of SOD increased with Zn application. The adverse influence of Zn-deficiency on
the light stage of photosynthesis is probably one of possible reasons for the limitation of photosynthetic capacity in maize
leaves. 相似文献
10.
选用抗旱型小麦品种陕合6号和水分敏感型小麦品种郑引1号的黄化幼苗为材料,研究了光处理对小麦幼叶脂氧合酶活性和膜脂氧化作用的影响。结果表明:光处理后黄叶变绿,叶片中的LOX活性降低,丙二醛含量和叶绿素含量增加,膜透性升高,IUFA升高。LOX活性与光抑制过程的恢复,光保护过程及膜脂过氧化作用有关。光诱导产生的膜脂过氧化作用是一种“准膜脂过氧化作用”。 相似文献
11.
Hanna Bandurska Ma?gorzata Pietrowska-Borek Ma?gorzata Cie?lak 《Acta Physiologiae Plantarum》2012,34(1):161-171
Responses of barley seedlings to water deficit (WD) induced by polyethylene glycol (PEG 6000) and ultraviolet (UV-B; 280–320 nm)
radiation and their interaction (UV-B + WD) were examined. A decrease in dry matter yield and water content of leaves and
roots was observed following application of WD and UV-B + WD, while no changes were found after treating barley plants with
UV-B. Proline content was increased in leaves under WD conditions and UV-B + WD. In contrast, UV-B treatment had no effect
on the accumulation of proline in leaves of barley plants. Changes in root proline content showed a varied response: WD induced
an increase in the level of this amino acid, while UV-B as well as UV-B + WD suppressed root proline content. The lipid peroxidation
product malondialdehyde (MDA) was increased in leaves under WD and UV-B + WD stresses. Root MDA content increased in WD-stressed
plants, but it decreased in the case of combined application of both stresses. The applied stress factors operated in a variable
manner on phenylpropanoid metabolism. Phenylalanine ammonia-lyase (PAL) activity in leaves and roots was stimulated after
exposure to WD and application of UV-B + WD stresses, while UV-B stress did not affect its activity. On the other hand, UV-B
treatment enhanced the activity of 4:coumarate-CoA ligase (4CL) in leaves and this enhancement was positively correlated with
the accumulation of anthocyanins and flavonols. However, the combined application of WD and UV-B reduced the positive effect
of UV-B on the accumulation of these compounds and the activity of 4CL. Surprisingly, anthocyanins and flavonols were not
detected in roots of examined barley seedlings despite increased 4CL activity. The results suggest that UV-B-induced activation
of 4CL as well as accumulation of anthocyanin and flavonols in leaves is beneficial for the response to this stress factor.
On the other hand, WD-induced reduction of the effect of UV-B on 4CL activity and the contents of anthocyanin and flavonol
might be a cause of membrane damage in UV-B- and WD-stressed plants. In addition, conversely to what could be expected, the
UV-B effect was perceived by the water-stressed roots, which exhibited reduced lipid peroxidation (MDA) and proline accumulation
in WD-stressed plants exposed to UV-B. 相似文献
12.
Jasmonic acid induced changes in protein pattern, antioxidative enzyme activities and peroxidase isozymes in peanut seedlings 总被引:1,自引:0,他引:1
G. J. Kumari A. M. Reddy S. T. Naik S. G. Kumar J. Prasanthi G. Sriranganayakulu P. C. Reddy Chinta Sudhakar 《Biologia Plantarum》2006,50(2):219-226
Protein pattern, ammonia content, glutamine synthetase activity, lipid peroxidation, superoxide dismutase, catalase, peroxidase
and peroxidase isoforms were studied in the leaves and roots of 7-d-old peanut (Arachis hypogaea L. cv. JL-24) seedlings treated by 25, 100 and 250 μM jasmonic acid (JA). SDS-PAGE protein profile of leaves and roots after
JA application showed a significant increase in 18, 21, 30, 45, 47 and 97.4 kDa proteins and significant decrease in 22 and
36 kDa proteins. Pathogenesis related PR-18 was specific in leaves at 250 μM JA and PR-21 have cross reacted differently with
21 and 30 kDa proteins in leaves and roots treated by all JA concentrations. Further, the immunoblot analysis with glutamine
synthetase, GS-45 antibodies revealed a specific cross reaction with 45 and 47 kDa proteins of both control and JA treated
leaves, however, higher at 100 and 250 μM JA treated leaves than control ones. Further, the malondialdehyde (MDA) content
significantly increased in leaves and roots treated with JA, indicated membrane damage with JA treatments that led to the
generation of peroxidation products. The peroxidase isozymic pattern showed two specific isoforms. Besides, the activities
of SOD and catalase were significantly elevated in JA treated leaves. 相似文献
13.
Polyamines content and physiological and biochemical responses to ladder concentration of nickel stress in Hydrocharis dubia (Bl.) Backer leaves 总被引:1,自引:0,他引:1
Influence of ladder concentration of nickel (Ni) on the leaves of Hydrocharis dubia were studied after 3 days treatment. The accumulation of Ni, the content of polyamines, proline, malondialdehyde (MDA) and
soluble protein, as well as the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in the leaves
were investigated. The result indicated that the toxicity of Ni manifested in respective aspect of physiological and biochemical
characters. Significant increase of Ni concentration in the leaf tissue was observed, which was concentration dependent. Visible
symptoms of Ni toxicity: chlorosis and necrosis occurred following the 3rd day. Meantime, treatment with Ni resulted in the
increase in the generation rate of O2•− in the leaves. SOD and CAT activities decreased significantly in response to Ni treatment, it was possibly the reason of
accumulation of O2•−. However, a several-fold decrease in POD activities was found. Our results indicated that because of prolonged increases
in O2•− level, oxidative damage, measured as the level of lipid peroxidation, occured in the leaves of Ni treated fronds. The changes
of the content of polyamines (PAs) were also investigated in the leaves of Hydrocharis dubia. Ni treatment significantly increased the putrescine (Put) level and lowered spermidine (Spd) and spermine (Spm) levels,
thereby significantly reducing the ratio of free (Spd + Spm)/Put in leaves, which has been considered as the signal under
stress. Although the trend that PS-conjugated PAs and PIS-bound PAs changed the same as free PAs, they changed in more less
extent. 相似文献
14.
Nitric oxide counteracts the senescence of detached rice leaves induced by dehydration and polyethylene glycol but not by sorbitol 总被引:12,自引:0,他引:12
In the present study, we evaluated the protective effect of nitric oxide(NO) against senescence of rice leaves enhanced by water deficit. Dehydration(DH), polyethylene glycol (PEG) and sorbitol (ST) treatments were used toinducewater deficit. Senescence of rice leaves was determined by the decrease ofprotein content. NO donors[N-tert-butyl--phenylnitrone (PBN), sodiumnitroprusside (SNP), 3-morpholinosydnonimine (SIN-1), and ascorbic acid +NaNO2] were effective in inhibiting senescence of dehydrated andPEG-treated rice leaves, but had no effect on senescence of ST-treated riceleaves. PEG or DH resulted in a marked increase in malondialdehyde (MDA)contentand decrease in superoxide dismutase (SOD) activity, but ST had no effect onMDAcontent and SOD activity. Treatment with NO donors caused a reduction of PEG-and DH-induced increase in MDA content and decrease in SOD activity. Theprotective effect of NO donors on promotion of senescence, increase in lipidperoxidation and decrease in SOD activity induced by PEG and DH was reversed by2-(4-carboxy-2-phenyl)-4,4,5,5- tetra-methylinmidazoline-1-oxyl-3-oxide, a NOspecific scavenger, suggesting that the protective effect of NO donors isattributed to NO released. The inhibition of PEG- and DH- enhanced senescenceofrice leaves by NO is most likely mediated through increasing SOD activity anddecrease in lipid peroxidation. 相似文献
15.
Issam Nouairi Wided Ben Ammar Nabil Ben Youssef Douja Daoud Ben Miled Mohamed Habib Ghorbal Mokhtar Zarrouk 《Acta Physiologiae Plantarum》2009,31(2):237-247
Plant species capable of hyper-accumulating heavy metals are of considerable interest for phytoremediation, and differ in
their ability to accumulate metals from environment. Using two brassica species (Brassica juncea and Brassica napus), nutrient solution experiments were conducted to study variation in tolerance to cadmium (Cd) toxicity based on (1) lipid
peroxidation and (2) changes in antioxidative defense system in leaves of both plants (i.e., superoxide dismutase (SOD EC
1.15.1.1), catalase (CAT EC 1.11.1.6), ascorbate peroxidase (APX EC 1.11.1.11), guaiacol peroxidase (GPX EC 1.11.1.7), glutathione
reductase (GR EC 1.6.4.2), levels of phytochelatins (PCs), non-protein thiols (NP-SH), and glutathione. Plants were grown
in nutrient solution under controlled environmental conditions, and subjected to increasing concentrations of Cd (0, 10, 25
and 50 μM) for 15 days. Results showed marked differences between both species. Brassica napus under Cd stress exhibited increased level of lipid peroxidation, as was evidenced by the increased malondialdehyde (MDA)
content in leaves. However, in Brassica
juncea treated plants, MDA content remained unchanged. In Brassica napus, with the exception of GPX, activity levels of some antioxidant enzymes involved in detoxification of reactive oxygen species
(ROS), including SOD, CAT, GR, and APX, decreased drastically at high Cd concentrations. By contrast, in leaves of Brassica juncea treated plants, there was either only slight or no change in the activities of the antioxidative enzymes. Analysis of the
profile of anionic isoenzymes of GPX revealed qualitative changes occurring during Cd exposure for both species. Moreover,
levels of NP-SH and PCs, monitored as metal detoxifying responses, were much increased in leaves of Brassica juncea by increasing Cd supply, but did not change in Brassica napus. These results indicate that Brassica juncea plants possess the greater potential for Cd accumulation and tolerance than Brassica napus. 相似文献
16.
Effects of flooding on the activities of some enzymes of activated oxygen metabolism, the levels of antioxidants, and lipid peroxidation in senescing leaves of tobacco were investigated. As judged by the decrease in chlorophyll and protein levels, flooding accelerated the senescence of tobacco leaves. Total peroxide and the lipid peroxidation product, malondialdehyde, increased in both control and flooding-treated leaves with increasing duration of the experiment. Throughout the duration of the experiment, flooded leaves had higher levels of total peroxide and malondialdehyde than did control leaves. Flooding resulted in an increase in peroxidase and ascorbate peroxidase activities and a reduction of superoxide dismutase activity in the senescing leaves. Glycolate oxidase, catalase, and glutathione reductase activities were not affected by flooding. Flooding increased the levels of total ascorbate and dehydroascorbate. Total glutathione, reduced form glutathione, or oxidized glutathione levels in flooded leaves were lower than in control leaves during the first two days of the experiment, but were higher than in control leaves at the later stage of the experiment. Our work suggests that senescence of tobacco induced by flooding may be a consequence of lipid peroxidation possibly controlled by superoxide dismutase activity. Our results also suggest that increased rates of hydrogen peroxide in leaves of flooded plants could lead to increased capacities of the scavenging system of hydrogen peroxide.Abbreviations GSH
reduced form glutathione
- GSSG
oxidized form glutathione
- GSSG reductase
glutathione reductase
- MDA
malondialdehyde
- SOD
superoxide dismutase 相似文献
17.
Heat shock (HS) reduced total lipid and phospholipid contents and their synthesis in germinating seeds of pigeonpea [Cajanus cajan (L.) Millspaugh]. Lipid peroxidation was also enhanced with increasing temperature and HS duration. HS influenced lipid metabolism to a higher extent at 45°C than at 40°C. This altered lipid metabolism and lipid peroxidation was associated with the loss of various solutes from the germinating seeds, and modification of growth and development. Pretreatment of germinating seeds at 40°C for 1 h or at 45°C for 10 min followed by incubation at 28°C for 3 h prior to 45°C for 2 h ameliorated solute leakage due to reduced lipid peroxidation and improvement in lipid content and membrane function. 相似文献
18.
Changes in ammonium ion content and glutamine synthetase activity in rice leaves caused by excess cadmium are a consequence of oxidative damage 总被引:5,自引:0,他引:5
Hsiu-Fang Chien Chuan Chi Lin Jen-Wu Wang Chien Teh Chen Ching Huei Kao 《Plant Growth Regulation》2002,36(1):41-47
Ammonium ion accumulation and the decrease in glutamine synthetase (GS)activity induced by CdCl2 were investigated in relation to lipidperoxidation in detached rice leaves. CdCl2 was effective inincreasing ammonium ion content, decreasing GS activity and increasing lipidperoxidation. Free radical scavengers (glutathione, thiourea, sodium benzoate)and an iron chelator (2,2-bipyridine) were able to inhibit the decreasein GS activity and ammonium ion accumulation caused by CdCl2 and atthe same time inhibit CdCl2-induced lipid peroxidation. Paraquat,which is known to produce oxygen radicals, decreased GS activity, increasedammonium ion content, and increased lipid peroxidation. GS1 appears to be thepredominant isoform present. Excess Cd caused a decrease in GS1 but not in GS2in detached rice leaves. An increase in lipid peroxidation preceded ammoniumionaccumulation and the decrease in GS1 activity. These results suggest that thedecrease in GS activity and the accumulation of ammonium ions in detached riceleaves are a consequence of oxidative damage caused by excess Cd. 相似文献
19.
Induction of Betalain Pigmentation in Hairy Roots of Red Beet under Different Radiation Sources 总被引:5,自引:0,他引:5
The effects of aluminum on lipid peroxidation and activities of antioxidative enzymes were investigated in detached rice leaves treated with 0 to 5 mM AlCl3 at pH 4.0 in the light. AlCl3 enhanced the content of malondialdehyde but not the content of H2O2. Superoxide dismutase activity was reduced by AlCl3, while catalase and glutathione reductase activities were increased. Peroxidase and ascorbate peroxidase activities were increased only after prolonged treatment, when toxicity occurred. The results give evidence that Al treatment caused oxidative stress and in turn, it caused lipid peroxidation. 相似文献
20.
The comparative alterations of short term NaCl stress and recovery on growth, water relations, ionic composition, lipid peroxidation
and antioxidants in roots of two rice cultivars differing in salt tolerance were studied. Exposed for 24 h to increasing (50,
100 and 150 mmol l−1) concentrations of NaCl, roots of 12D Oryza sativa L. cv. Lunishree and cv. Begunbitchi decreased in fresh weight, dry weight and relative water content. Increased Na+ and decreased K+ ion were determined at increasing NaCl concentrations. Both peroxide content and lipid peroxidation measured in terms of
MDA level increased and the ratio was higher in Begunbitchi compared to Lunishree. Recovered roots showed lower peroxide and MDA content. Ascorbate and glutathione contents increased in the stressed and
recovered roots of Lunishree, but decreased in Begunbitchi with increasing NaCl concentrations. Although SOD, CAT and GR activities decreased in the stressed roots, CAT activity also
increased in recovered roots of both the cultivars. The POX activity increased in stressed and recovered roots of both Lunishree and Begunbitchi. Higher free radicals scavenging capacity and more efficient protection mechanism of Lunishree against salt stress, as revealed by the lower level of lipid peroxidation and improved plant water status as well as activities
of some of the antioxidants, suggest that significant cultivar differences in response to salt stress in rice are closely
related to differences in the activities of antioxidants and ion content. Another possible conclusion is that improved tolerance
to salt stress may be accomplished by increased capacity of antioxidative system. 相似文献