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Zhong-Jing Liu Xiao-Long Zhang Ji-Gang Bai Bang-Xia Suo Pei-Lei Xu Lin Wang 《Scientia Horticulturae》2009
In order to examine whether paraquat modifies the functioning of antioxidants and oxidative stress levels in drought-stressed plants, a cucumber cultivar (Cucumis sativus cv. Yuexiu no. 3) was grown hydroponically for 2 days. Drought stress, which was induced by polyethylene glycol (PEG), increased the contents of malonaldehyde (MDA), superoxide radical (O2−) and hydrogen peroxide (H2O2) in cucumber leaves, while pretreatment of paraquat decreased them. Under drought stress induced by PEG, we observed the decreased contents of MDA, H2O2 and O2− in paraquat-pretreated plants in comparison to unpretreated stressed plants. Drought stress and paraquat both increased the activities of antioxidants such as superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), guaiacol peroxidase (GPX, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11), dehydroascorbate reductase (DHAR, EC 1.8.5.1), monodehydroascorbate reducatase (MDHAR, EC 1.6.5.4), glutathione reductase (GR, EC 1.6.4.2), reduced glutathione (GSH) and reduced ascorbate (AsA). But the combined effect of paraquat application and drought stress resulted in the highest activities of antioxidants. So paraquat is able to moderate the activities of scavenging system enzymes and to influence oxidative stress intensity under drought stress induced by PEG. 相似文献
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The objective of this study was to determine diversities of ascorbic acid (AsA) and activities of enzymes involved in AsA metabolism, and to determine their relationships to AsA content in the leaves of Chinese persimmon (Diospyros kaki) cultivars. Results showed that there were huge differences not only in the contents of AsA and glutathione (GSH) but also in the enzyme activities of l-galactono-1,4-lactone dehydrogenase (GLDH, EC 1.3.2.3), dehydroascorbate reductase (DHAR, EC 1.8.5.1), monodehydroascorbate reductase (MDHAR, EC 1.6.5.4), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) in the leaves of 22 Chinese persimmon cultivars. Control of AsA levels mainly depended on the capacity for biosynthesis and GLDH activity played a main role in determining AsA levels in the leaves of persimmon. Both MDHAR and DHAR, MDHAR in particular, also played an important role in maintaining AsA redox state by reducing oxidized AsA back to AsA. But contents of GSH and hydrogen peroide (H2O2) and activity of APX were not significantly correlated with AsA content in the leaves of persimmon. 相似文献
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Exposure of Satsuma mandarin (Citrus unshiu Marc.) and Navel orange (Citrus sinensis Osbeck) plants to high temperature (38 °C) led to reductions of the net photosynthetic rate (Pn), the photorespiration rate (Pr), the quantum efficiency CO2 assimilation (ΦCO2), the maximal photochemical efficiency of PS2 (Fv/Fm), the photochemical quenching (qP) and the quantum efficiency of PS2 photochemistry (ΦPS2), whereas the minimal fluorescence yield (Fo) and the non-photochemical quenching (qN) increased. Increase in the value of Pr/Pn and ΦPS2/ΦCO2 was attributed to the greater decrease in Pn and ΦCO2 than Pr and ΦPS2. In addition, the superoxide radical (O2−) production, the H2O2 concentration and the activities of antioxidant enzymes such as the superoxide dismutase (SOD, EC 1.15.1.1), the ascorbate peroxidase (APX, EC 1.11.1.11), the dehydroascorbate reductase (DHAR, EC 1.8.5.1) and the catalase (CAT, EC 1.11.1.6) were raised. On the other hand, the chlorophyll concentration in leaves decreased during high temperature stress. These results suggest that decline in Pn related to inactivation of PS2 reaction centers may be due to the enhanced number of active oxygen species in the citrus leaves. The water–water cycle may play a role in limiting the degree of photodamage caused by high temperature. Lower O2− production rate, the H2O2 concentration and the antioxidant enzymes activity were observed in high temperature tolerant species of citrus. The exogenous active oxygen scavenger ascorbic acid (Asc) enhanced the ability to clear the O2− in citrus plants, and quicken the recovery of photosynthetic apparatus. 相似文献
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The objective of this work was to evaluate how disease resistance and reactive oxygen species (ROS) metabolism in harvested navel oranges (Citrus sinensis L. Osbeck) may be affected by chitosan. Fresh navel oranges were treated with 2% chitosan or 0.5% glacial acetic acid (control) solution for 1 min, and some were inoculated with Penicillium italicum and Penicillium digitatum. Then, the fruit were stored at 20 °C and 85–95% RH. Treatment with 2% chitosan significantly reduced the disease incidence and the lesion diameter compared with control fruit. This treatment effectively enhanced the activities of peroxidase (POD) and superoxide dismutase (SOD), and levels of glutathione (GSH) and hydrogen peroxide (H2O2), inhibited the activities of catalase (CAT) and the decreases of ascorbate (AsA) content during navel orange fruits storage. Ascorbate peroxidase (APX) activity in the navel orange fruit was induced slightly by the chitosan treatment during 14–21 days storage. However, glutathione reductase (GR) activity in the fruit was not enhanced by the chitosan treatment. These results indicated that chitosan treatment could induce the navel orange fruit disease resistance by regulating the H2O2 levels, antioxidant enzyme and ascorbate–glutathione cycle. 相似文献
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Effect of brassinosteroids on drought resistance and abscisic acid concentration in tomato under water stress 总被引：1，自引：0，他引：1
Gao-Feng Yuan Cheng-Guo Jia Zhen Li Bo Sun Li-Ping Zhang Na Liu Qiao-Mei Wang 《Scientia Horticulturae》2010
The effect of brassinosteroid (BR) on relative water content (RWC), stomatal conductance (gs), net photosynthetic rate (PN), intercellular CO2 concentration (Ci), lipid peroxidation level, activities of antioxidant enzymes and abscisic acid concentration (ABA) in tomato (Lycopersicon esculentum) seedlings under water stress was investigated. Two tomato genotypes, Mill. cv. Ailsa Craig (AC) and its ABA-deficient mutant notabilis (not), were used. Water stress was achieved by withholding water and both the AC and not plants were treated with 1 μM 24-epibrassinolide (EBR) or distilled water as a control. The RWC, gs, Ci and PN were significantly decreased under water stress. However, EBR treatment significantly alleviated water stress and increased the RWC and PN. EBR application also markedly increased the activities of antioxidant enzymes (catalase, ascorbate peroxidase and superoxide dismutase) while it decreased gs, Ci and the contents of H2O2 and malondialdehyde (MDA). Interestingly, ABA concentration in AC and not plants was markedly elevated after EBR treatment although the increasing rate and amplitude of ABA in not plants treated by EBR was significantly lower than those in AC plants. Our study suggested that amelioration of the drought stress of tomato seedlings may be caused by EBR-induced elevation of endogenous ABA concentration and/or the activities of antioxidant enzymes. 相似文献
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The beneficial effect of compost, the final product of aerobic biodegradation of organic matter, on growth, lipid peroxidation [as malondialdehyde (MDA], hydrogen peroxide (H2O2) and superoxide anion (O2•−), activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR), as well as reduced ascorbate (ASC) and glutathione (GSH) and their oxidized forms was investigated in squash (Cucurbita pepo L. cv. Eskandarany) plants exposed to normal and low temperature (LT) conditions. LT stress of 8 °C significantly reduced the plant growth of untreated plants, but compost alleviated the adverse effect of stress and significantly increased the fresh and dry weights under normal and stress conditions. LT also induced accumulation of H2O2 and O2•− and resulted in increased lipid peroxidation, pointing out to cellular oxidative stress. Under compost application, such reactive oxygen species (ROS) and peroxidized lipids were markedly reduced, but SOD, CAT, APX and GR activities, key enzymes of ROS-scavenging systems, were significantly increased. Data also indicated that there were general reductions in total ascorbate and glutathione pool in LT control plants, but compost-treated ones considerably have maintained higher levels of such redox metabolites. Significantly higher ratios of ASC/DHA (dehydroascorbate) and GSH/GSSG (glutathione disulfide) were generally found in compost-treated plants than in untreated-ones. It is evident that compost induced enhancement of LT tolerance was related to up-regulation of enzymatic and non-enzymatic antioxidant systems. Such enhancement would eventually protect plant cells from LT-induced oxidative stress reactions via scavenging ROS. 相似文献
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Individual and combined effects of salinity and B toxicity on growth, the major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX) activities, ascorbic acid, proline, and H2O2 accumulation, and stomatal resistance (SR), malondialdehyde (MDA), membrane permeability (MP) and the concentrations of sodium (Na), chloride (Cl) and boron (B) of lettuce were investigated. Boron toxicity and salinity reduced growth of lettuce plants. Under B toxicity, B concentration of the plants was increased, but in the presence of NaCl, the concentration of B was significantly reduced. Sodium and Cl concentrations were increased in B + NaCl and NaCl treatments. Membrane damage was more pronounced in NaCl and B + NaCl treatments. Stomatal resistance of the plants was significantly increased by salinity treatments. The accumulation of proline and ascorbic acid was the highest in the B + NaCl treatment. In general, stress conditions significantly increased H2O2 and antioxidant enzyme (SOD, CAT and APX) activities. The present results indicate that stomatal closure is an important response of lettuce against NaCl and B + NaCl stress. Furthermore NaCl and B + NaCl toxicity-induced oxidative stress in lettuce resulting in lipid peroxidation and membrane damage. Increased antioxidant enzyme activities and also accumulation of ascorbic acid and proline are involved in order to overcome B- and NaCl-induced oxidative stress. 相似文献
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Nader Kazemi Ramazan Ali Khavari-NejadHamid Fahimi Sara SaadatmandTaher Nejad-Sattari 《Scientia Horticulturae》2010
The effects of nickel in combination with salicylic acid (SA) and sodium nitroprusside (SNP), a donor of nitric oxide (NO) on 21-day-old canola plants were evaluated. Exposure to 0.5 mM NiCl2·6H2O for 10 days resulted in toxicity symptoms such as chlorosis and necrosis at leaves. Addition of 0.2 mM SA or 0.2 mM SNP slightly reduced the toxic effects of nickel. After application of both SA and NO, these symptoms considerably decreased. Treatment with Ni resulted in a decrease in dry weight of roots and shoots and chlorophyll content of leaves. In Ni-treated plants, level of lipoxygenase activity and malondialdehyde (MDA), H2O2 and proline contents significantly increased, while the activities of the antioxidant enzymes such as catalase, guaiacol peroxidase and ascorbate peroxidase decreased in leaves. The results indicated that Ni caused an oxidative stress in canola plants. The Ni-stressed plants exposed to SA or NO, especially to SA + NO, exhibited an improved growth as compared to Ni-treated plants. SA or NO, especially both together considerably reduced root-to-shoot translocation of Ni and increased the activities of the antioxidant enzymes in leaves of Ni-stressed plants. Interaction of SA and NO improved the chlorophyll content and decreased the level of lipid peroxidation, H2O2 and proline accumulation in leaves. These results suggest that SA or NO in particular their combination counteract the negative effects of Ni on canola plants. 相似文献
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外源过氧化氢对干旱胁迫下温室黄瓜叶绿体超微结构和抗氧化酶的影响 总被引：6，自引：0，他引：6
以温室黄瓜品种‘春光2号’为试材, 用100 g·L - 1聚乙二醇处理模拟干旱胁迫, 研究外源过氧化氢是否通过提高叶片抗氧化酶的活性来减轻干旱胁迫对叶绿体膜的伤害。结果表明: 干旱胁迫处理48 h后, 叶绿体肿胀变圆, 叶绿体膜和类囊体模糊不清。与干旱胁迫前没有经过预处理的幼苗相比, 经外源过氧化氢预处理后再干旱胁迫48 h的幼苗中大部分的叶绿体结构正常, 叶片的超氧化物歧化酶、过氧化氢酶、愈创木酚过氧化物酶、抗坏血酸过氧化物酶、单脱氢抗坏血酸还原酶、脱氢抗坏血酸还原酶和谷胱苷肽还原酶等抗氧化物酶的活性以及抗坏血酸和还原型谷胱苷肽的含量明显增高, 内源过氧化氢含量、超氧阴离子的产生速率和丙二醛的含量则显著降低。所以, 外源过氧化氢预处理能够提高抗氧化物的活性,降低活性氧的积累, 从而缓解干旱对黄瓜叶绿体膜的伤害。 相似文献
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Low seed germination is a major problem in commercial rose propagation and breeding and is species-dependent. The present work selected four rose species previously un-examined to explore effective methods for improving seed germination and the relevant dormancy mechanism and its levels in seven experiments. The results showed that both pulp and achenes from the four rose shrubs had chemical substances that significantly inhibited seed germination with the inhibitory effect was more pronounced in pulp extract than of achenes. Single treatments of H2SO4 scarification, short-term cold stratification (<16 weeks) or warm stratification were less effective in breaking dormancy as indicated by lower germination index than their combinations. Comprehensive comparisons showed that among the six treatments the most effective for breaking dormancy was H2SO4 scarification followed by warm plus cold stratification, then H2SO4 scarification followed by cold stratification and finally warm plus cold stratification. Scarification with H2SO4 for 2–4 h ordinal followed by warm stratification at 20 °C for 4 weeks and cold stratification at 5 °C for 8 weeks was the best pretreatment for increasing seed germination percentage for Rosa multibracteata (81.4 ± 2.9%), Rosa hugonis (13.1 ± 6.0%), and Rosa filipes (62.7 ± 5.7%); and H2SO4 scarification for 4 h followed by cold stratification at 5 °C for 12 weeks was the best pretreatment for Rosa sericea (46.7 ± 8.7%). Our results suggest that these four species have only physiological dormancy caused by integrative roles of pulp, pericarp and embryo. The level of physiological dormancy was ranked as R. hugonis > R. sericea > R. filipes > R. multibracteata. 相似文献
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Exogenous nitric oxide on antioxidative system and ATPase activities from tomato seedlings under copper stress 总被引：1，自引：0，他引：1
Nitric oxide (NO) serves as a bioactive molecule involved in antioxidant and anti-stress agent in tolerance responses to abiotic stress. Here, we investigated the effects of exogenous sodium nitroprusside (SNP), a NO donor, on both the ROS metabolism and functions of plasma membrane and tonoplast in tomato plants treated with 50 μM CuCl2. The copper stress markedly decreased shoot height, fresh weight, induced significant accumulation of H2O2, and led to serious lipid peroxidation in tomato plants. The application of 100 μM SNP significantly alleviated the growth inhibition, promoted ROS-scavenging enzymes, reduced H2O2 content in tomato plants, and alleviated the inhibition of H+-ATPase and H+-PPase in plasma membrane or tonoplast induced by CuCl2. While application of sodium ferrocyanide (an analog of SNP) and sodium nitrate or nitrite (the decomposition product of NO or its donor SNP) which did not release NO, did not show the effects of SNP; furthermore, the effects of SNP were reversed by addition of hemoglobin (a NO scavenger). All together, these results suggested that exogenous NO could be advantageous against copper (Cu) toxicity, and could confer tolerance to heavy metal stress in tomato plants. 相似文献
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Sweet orange (Citrus sinensis L. Osb.) ‘Hamlin’ is a canker (Xanthomonas axonopodis pv. citri: Xac) susceptible citrus genotype grown commercially worldwide. Canker causes severe economic losses and restricts the marketability of crop for export. Little is known about the role of oxidative stress in canker development. In the present investigation, sweet orange ‘Hamlin’ leaves were artificially inoculated with Xac to determine the impact of Xac infection on hydrogen peroxide (H2O2) metabolism. Characteristic symptoms following artificial inoculation were water soaking of the infiltrated zone between 2 and 8 days after inoculation (dai); raised epidermis accompanying tiny yellow colored bacterial colonies at 8 dai; and yellowing and necrosis of the infected zone by 12–16 dai. In planta Xac population increased 1000 fold by 14 dai from an initial population of 7.3 × 106 cfu cm−2 (0 dai). Peak concentrations of H2O2 were observed at 24 h and between 8 and 10 dai and coincided with higher activity of total superoxide dismutase (SOD). Lower levels of H2O2 in infected leaves were maintained by Xac induced higher activities of catalase (CAT), ascorbate peroxidase (APOD), and guaiacol peroxidase (POD). It appears Xac altered H2O2 metabolism in C. sinensis L. Osb. ‘Hamlin’ to enhance survival and growth. 相似文献
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We investigated individual and combined effects of B toxicity and salinity in the presence or absence of silicon on the shoot growth, concentrations of sodium (Na), chloride (Cl), boron (B) and silicon (Si), and stomatal resistance (SR), lipid peroxidation (MDA), proline accumulation, H2O2 accumulation and the activities of major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT and ascorbate peroxidase, APX) activity grapevine rootstocks of 41B (V. Vinifera × V. Berlandieri) and 1103P (V. Berlandieri × V. Rupestris). Applied Si counteracted the deleterious effects of salinity and boron toxicity on shoot growth by lowering the accumulation of Na in 1103P, and B and Cl in the both rootstocks. Stomatal resistance, MDA, and the concentrations of H2O2 and proline were higher in the plants grown in conditions of B toxicity, salinity and their combination while applied Si lowered these parameters. Lowering SOD and CAT but increasing APX, Si treatment significantly affected the enzyme activities of both rootstocks. Based on the present work, it can be concluded that Si alleviates the adverse effects of salinity, B toxicity and combined salinity-B toxicity on grapevine rootstocks by preventing both oxidative membrane damage and translocation of Na and B from root to shoots and/or soil to plant, and also lowering the phytotoxic effects of Na and B within plant tissues. When considering the antioxidative response and membrane systems, it was concluded that the rootstock 1103P was responsive to Si under stress conditions. To our knowledge, this is the first report that Si improves the combined salt and B tolerance of grapevine grown under saline, B toxic, and B toxic and saline conditions which describes membrane related parameters and antioxidant responses. 相似文献
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利用人工智能模拟霜箱,设8 个温度（18、–1、–2、–3、–4、–5、–6、–7 ℃）,对
抗寒性不同的两个仁用杏（Prunus armeniaca Linn.）品种雌蕊的过氧化氢（H2O2）含量和抗坏血酸-谷胱
甘肽（AsA-GSH）循环进行了研究。结果表明,低温胁迫增加了仁用杏雌蕊H2O2 含量,–7 ℃时抗晚霜
品种‘围选1 号’和晚霜敏感品种‘龙王帽’分别为对照（18 ℃）的 5.49 倍和7.22 倍。低温期间,‘围
选1 号’雌蕊AsA 等酶含量及APX 等酶活性均高于‘龙王帽’,–7 ℃时,‘围选1 号’雌蕊AsA、MDHA、
DHA、GSH 和GSSG 含量比对照分别下降了66%、69%、48%、52%、53%,‘龙王帽’下降了78%、79%、
59%、66%、65%,–7 ℃时,‘围选1 号’雌蕊APX、MDHAR、DHAR、GPX、GR 活性、AsA/DHA、
GSH/GSSG 分别是对照的2.87 倍、1.07 倍、1.42 倍、1.60 倍、1.20 倍、65%和1.03 倍,‘龙王帽’是对照
2.41 倍、96%、1.13 倍、1.08 倍、98%、54%、97%。结果表明‘围选1 号’雌蕊在低温期间有较高的AsA-GSH
循环效率,可有效抑制H2O2 的积累,这可能是其抗晚霜能力较强的重要原因之一。 相似文献
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Jinn-Chin Yiu Lao-Dar Juang Denise Yi-Tan Fang Cheng-Wei Liu Sheng-Ju Wu 《Scientia Horticulturae》2009
Soil flooding is an environmental factor of seasonal occurrence that negatively affects plant performance. Polyamines play an important role in the plant response to adverse environmental conditions including flooding stress. The objective of the present study was to assess the comparative oxidative damage to Welsh onion plants caused by flooding stress and to examine the role of putrescine (Put) in this response. Welsh onion plants were treated with Put prior to 10 d flooding. A positive effect was observed when treating with 2 mM Put. Exogenous application of Put resulted in alleviation of flooding-induced reduced relative water content, plant growth and chlorophyll fluorescence. Superoxide radical (O2−) and hydrogen peroxide (H2O2) contents were also reduced in stressed plants after Put pre-treatment and thereby the oxidative stress in plant cells was lowered. The antioxidant system, as an important component of the waterlogging-stress-protective mechanism including α,α-diphenyl-β-picrylhydrazyl (DPPH)-radical scavenging activity, superoxide anion radical scavenging, metal chelating activities and reducing power, can be upgraded by Put, which is therefore able to moderate the radical scavenging system and to lessen oxidative stress. Under non-flooding conditions, the anti-oxidative activity of Welsh onion was regulated and elevated by Put pre-treatment. These results suggest that Put confers flooding tolerance to Welsh onion, probably through inducing the activities of various anti-oxidative systems. Thus, exogenous 2 mM per plant of Put 24 h prior to flooding could alleviate flooding stress. 相似文献
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The dormancy mechanisms of Areca triandra Roxb. Ex Buch-Ham seeds were studied by treating the intact or mechanically scarified seeds with scarification, chemical soaking and stratification. The results indicate that the seeds have exogenous and endogenous dormancy. The exogenous dormancy is imposed by the pericarp and it is the major limiting factor for germination. It can be broken by mechanical scarification, but not by chemical scarification in 98% H2SO4 for 30 min. Chemical treatments (soaking for 24 h in 100–200 mg/L GA3, 0.2% KNO3 and 0.1–0.3% NaNO2, and for 12 h in 10% H2O2 or 20 min or 12 h in 15% H2O2) and stratifications, especially, cold stratifications for 30–120 days, broke the endogenous dormancy and significantly hastened germination of mechanically scarified seeds, although they did not increase the germination percentages. 相似文献