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1.
To evaluate their salt tolerance, two-year-old potted honeysuckle plants were exposed to 50, 100, and 150 mM NaCl, respectively. The effects of salt stress on growth parameters, ion concentration, lipid peroxidation, and the enzymatic antioxidant system in honeysuckle were studied. Salt stress reduced biomass accumulation and root activity, and also induced oxidative stress, as indicated by elevated levels of O2·-, malondialdehyde content, and electrolytic leakage. Increased salinity resulted in a slight decline in the K+ concentration in different plant tissues, but a significant boost in Na+ levels, which were much higher in roots than in other tissues. The concentrations of Ca2+ and Mg2+ increased significantly in leaves, but remained unchanged in shoots and decreased slightly in roots. Higher levels of soluble sugars and proline were observed in the plants after 30 days of NaCl treatment, suggesting that compatible osmolytes had been synthesised to acclimatise to the salinity. Under the treatments, major antioxidant enzymes involved in the reactive oxygen species scavenging system, including superoxide dismutase, ascorbate peroxidase, catalase and peroxidase were activated. The increased activities of the antioxidant enzymes were significant and occurred in a time-dependent manner.  相似文献   

2.
采用营养液栽培,以黄瓜品种新泰密刺为试材,研究了外源Ca(NO3)2对盐胁迫(NaCl 65 mmol.L-1)下黄瓜幼苗生长、膜质过氧化产物丙二醛(MDA)含量及电解质渗漏率的影响。结果表明:Ca(NO3)2处理可以缓解盐胁迫对黄瓜幼苗生长的抑制,降低盐胁迫引起的MDA含量和电解质渗漏率升高的幅度。其中以2.0mmol.L-1Ca(NO3)2处理效果最好,黄瓜幼苗地上部鲜质量、地上部干质量、株高、茎粗、叶面积、地下部鲜质量、地下部干质量、总根长、总根表面积、总根体积、根尖数等生长指标均显著高于单独盐胁迫处理,同时显著降低了盐胁迫下MDA和电解质渗漏率的上升辐度。  相似文献   

3.
The effects of NaCl stress on plant growth, gas-exchange, activity of superoxide dismutase (SOD), rate of lipid peroxidation, and accumulation of Na+ ion and sugar were investigated in leaves and fruits of pepper plants (Capsicum annuum L.). Especially, the gene expression of l-galactono-1,4-lactone dehydrogenase (GalLDH), which is the last enzyme of ascorbic acid (AsA) biosynthesis, and the relationships between AsA level and Na+ concentration in plant tissue were investigated with increasing salinity. Plants were treated with three treatments: the control (0 mM NaCl) and two salinity levels (50 and 100 mM NaCl) for 21 days under greenhouse conditions. Plant growth was markedly restricted due to the reduction of photosynthetic rate and the increase of Na+ accumulation in leaves with the increasing intensity of NaCl stress. Salinity had more effect on fruit growth comparing to leaf growth, suggesting that fruits could be more sensitive to salinity than leaves. In comparison with the control, salt stress significantly increased lipid peroxidation (as measured as malondialdehyde content) but decreased SOD activity in both fruits and leaves although the effect was larger in fruits; and the rate of the decrease in SOD activity was greater than that of the increase in lipid peroxidation. The AsA concentration transiently increased first 7 days but it slightly decreased from the initial level in the end of treatment day 21. The change in GalLDH gene expression was similar to AsA concentration. The accumulation of Na+, the reduction of AsA level at severe salinity stress were greater in fruits than in leaves; and AsA level had a negative relationship with Na+ concentration in both leaves and fruits. These results suggest that the difference in salt sensitivity between fruits and leaves in pepper plants can be related to the difference in inhibition of AsA synthesis, which in turn is probably due to the toxicity of extreme accumulation of Na+.  相似文献   

4.
Zinc (Zn) and boron (B) disorders are common nutritional stresses in arid and semi-arid regions. In the current study, effectiveness of soil Zn amendment (0, 5.0, 10.0, and 20.0 mg kg–1 soil) using Zn-glycine chelate (Zn-Gly), a novel Zn-fertilizer, which is especially synthesized for application in calcareous soils in arid and semi-arid areas, was evaluated under different soil B levels (0, 2.5, 5.0, 10.0, and 20.0 mg kg–1 soil) for a 100-day period. Pistachio, the most valuable crop grown under arid conditions, was used as the model plant. Measurement of electrolyte leakage, H2O2, and malondialdehyde indicated the incidence of oxidative stress in the leaves of pistachio under low and high soil B concentrations. In addition, B stress caused a significant increase in lipoxygenase activity in the leaves. Plants treated with 5.0 mg B kg–1 soil showed the lowest oxidative stress injuries and lipid peroxidation. Application of 5.0 mg Zn kg–1 soil significantly alleviated the B stress damages, however, the ameliorative effect of Zn was vanished by application of higher Zn concentrations. Evaluation of the antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], or ascorbate peroxidase [APX]) and non-enzyme antioxidants (ascorbate and phenolic compounds) revealed that the protective effects of Zn-Gly against B stress are due to enhancement of cell antioxidant defense. In conclusion, application of Zn-Gly for reducing oxidative stress pressure in pistachio plants grown under B disorder was suggested.  相似文献   

5.
低温胁迫对油桃花器官膜脂过氧化和保护酶活性的影响   总被引:28,自引:0,他引:28  
低温胁迫下油桃(Amygdalus persicavar.nectariana)花器官不同组织细胞膜透性变化趋势相似,即从缓慢增长到急剧上升之后缓慢上升。MDA含量随着低温胁迫的加剧也表现出相似的变化趋势。花器官不同,膜透性和MDA增加的幅度和临界温度不同。花器官各部分保护酶SOD、POD、CAT和APX活性,在低温胁迫前期均逐渐升高,在达到一定的临界低温后,呈现下降的趋势。这表明花器官内保护酶的存在和活性的提高减轻了由膜脂过氧化引起的伤害,是植物组织提高抗寒性、免遭低温伤害的重要原因。  相似文献   

6.
Bitter gourd (Momordica charantia L.) seedlings treated with elevated concentrations of dimethoate (100 and 200 ppm) and fixed ultraviolet-B (0.4 Wm−2/30 min) irradiation showed stunted growth and less photosynthetic pigments chlorophylls (Chl) content. The synergistic effects of both the stresses were more pronounced than the individual effect. However, dimethoate at low concentration (50 ppm) stimulated growth and pigmentation but with UV-B it showed slight inhibition. Reactive oxygen species (ROS) accumulated considerably in leaves due to UV-B and high concentrations of dimethoate. Combined exposure further increased the ROS leading to lipid peroxidation and electrolyte leakage. Both the stresses alone and together also caused the increase activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). High concentration of dimethoate and UV-B accelerated the accumulation of ROS particularly H2O2 in leaves, causing heavy damage to photosynthetic pigments and growth of bitter gourd seedlings. Simultaneous exposure of UV-B and dimethoate inhibit the growth, photosynthetic pigment and enhanced the accumulation of ROS more severely than the individual exposure. Interestingly, low concentration (50 ppm) of dimethoate significantly reduced the effects of UV-B. The results suggested synergistic effect of dimethoate and UV-B on plant growth as a function of decreased photosynthetic pigments despite increase in the activities of the antioxidant enzyme.  相似文献   

7.
Paclobutrazol (PBZ) is a member of the triazole plant-growth inhibitor group that is responsible for inducing tolerance to number of biotic and abiotic stresses. An experiment was, therefore, conducted to test whether PBZ application at various concentrations (0, 25, 50 and 75 mg L−1) through seed soaking or foliar spray would protect watermelon (Citrullus lanatus) seedlings, subjected to chilling stress. Thirty-five-day old plants were exposed to chilling 5 h/day at 4 °C for 5 days. PBZ improved growth rate of watermelon seedling subjected to chilling stress and increased relative leaf chlorophyll content (RLCC) and chlorophyll fluorescence ratio (Fv/Fm) compared with the control at the end of chilling stress. PBZ ameliorated the injury caused by chilling stress by inhibiting increases in proline and leaf electrolyte leakage, which suggested that PBZ ameliorated the negative effect of chilling stress. PBZ was most effective in increased chilling tolerance of watermelon seedling when applied using the seed soak method than as a foliar spray. The best protection appeared to be obtained from seedlings seed soaked with PBZ at 50 and 75 mg L−1.  相似文献   

8.
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   

9.
 用浓度为225mmol·L-1的NaCl溶液对黄瓜不同耐盐品种进行处理,研究NaCl胁迫对黄瓜不同耐盐品种叶片膜脂过氧化及脯氨酸含量的影响。结果初步表明,在一定盐浓度下,随着处理天数的延长,耐盐品种和盐敏感品种的膜脂过氧化明显加剧,丙二醛含量和质膜透性明显升高并且差异显著,变化趋势稳定;而脯氨酸含量呈波动式变化,且变化趋势不稳定。因此,丙二醛含量和质膜透性可作为鉴定本试验黄瓜品种耐盐性的生理指标,脯氨酸含量则不宜作为鉴定本试验黄瓜品种耐盐性的生理指标。  相似文献   

10.
外源NO对高温胁迫下姜叶片活性氧代谢的影响   总被引:2,自引:0,他引:2  
李秀  巩彪  徐坤 《园艺学报》2014,41(2):277-284
为探讨姜对高温胁迫的生理响应特性,采用砂培法,研究了高温对姜叶片活性氧代谢的影响及培养液添加NO供体硝普钠(SNP)缓解高温胁迫的作用。结果表明,高温胁迫显著降低姜叶片色素含量,增加产生速率及H2O2和MDA含量;叶片SOD、POD、CAT等抗氧化酶活性在高温胁迫初期增强,随胁迫时间延长急剧下降;同时,AsA–GSH循环遭受破坏。外源添加0.1 mmol · L-1 SNP能显著增强姜叶片的抗氧化酶活性,降低叶片ROS水平,减轻膜脂过氧化程度,维持AsA–GSH循环系统的稳定性;降低叶片色素降解,有效缓解高温对姜叶片造成的伤害,增强其耐热性。  相似文献   

11.
Summary

Changes in electrolyte leakage were assessed on the skin, outer and inner mesocarp of hot-water treated mangoes at the end of 2, 5, 10 d during storage at 4, 9, and 138C respectively. Batches of fruit were subjected to hot-water treatments at the following time-temperature combinations: (1) untreated; (2) 36.58 for 75 min; (3) 36.58C for 60 min stepped up to 46.58C for 43 min, or 46.5C for 90 min (same heat units), and (4) 36.58C for 75 min plus 46.58C for 61 min or 46.58C for 120 min (same heat units). The time-temperature combinations were designed to ensure that the fruits received heat units equivalent to about 0, 1/2, 1 or 11/3 of (468C for 90 min). Electrolyte leakage in fruit tissue was significantly highest in inner tissue and lowest in the fruit skin. The leakage increased in all fruit parts over time and with rise in storage temperature. Significant changes in electrolyte leakage were observed only in fruits stored at 138C. The skin of mangoes immersed in hot water at 46.58C for 120 min showed significantly higher electrolyte leakage compared with control and phased hot-water treatment (368C for 60 min + 46.58C for 43 min). Phased hot-water treatments showed lower electrolyte leakage compared with constant (one-stage) hot-water treatments and control. Fruits that received heat equivalent to 1 or 11 Ï /3 of 46.58C for 90 min through phased hot water showed lower leakage compared with constant hot water immersion at the same heat units. Linear regression of natural logarithms of electrolyte leakage against calcium contents showed a strong negative correlation. Hot-water treatment at 46.58C for more than 60 min exacerbated the problem of fruit skin damage especially during storage at 138C.  相似文献   

12.
掌裂草葡萄是观赏价值很高的多年生藤本植物,在寒地园林垂直绿化中具有很好的推广价值。目前对其抗盐性研究未见报道。本试验通过对掌裂草葡萄一年生播种苗进行不同浓度的NaCl胁迫处理,研究其细胞膜透性,渗透调节物质(可溶性糖、可溶性蛋白)、保护酶活性(SOD、POD)在盐胁迫下的变化规律,揭示掌裂草葡萄的耐盐性。结果表明:掌裂草葡萄对NaCl胁迫有一定的应激性,胁迫使可溶性蛋白含量和SOD活性迅速增大;各处理随胁迫时间的延长膜透性逐渐增大,胁迫浓度越大,电解质外渗越多。400mmol/L胁迫处理第18d,电解质外渗达50%以上,处理第30d植株死亡;浓度300mmol/L及以上时,可溶性糖、可溶性蛋白和SOD活性在处理第18d开始迅速下降,POD活性在处理第30d下降,可溶性糖含量和SOD活性分别在第24d和第30d低于对照。由此推断,300mmol/L及以上的NaCI胁迫不利于掌裂草葡萄的生长。  相似文献   

13.
14.
Summary

The effects of 75 mM and 150 mM NaCl (EC 8.50 and 15.35 dS m–1) were studied on a salt-tolerant and a salt-sensitive pepper (Capsicum annuum L.) genotype. The salt-tolerant genotype showed lower declines in relative water content (RWC), no change in chlorophyll (Chl) content, lower increases in lipid peroxidation, and greater increases in superoxide dismutase (SOD) activity, total protein content, and glutathione content. The salt-sensitive genotype showed greater decreases in RWC, Chl content, SOD activity, and in guaiacol peroxidase (GPOX) activity, and higher increases in lipid perxidation and the amount of proline, with a negligible increase in glutathione content.These results revealed that increases occurred in some anti-oxidative stress enzymes in the salt-tolerant pepper genotype, as well as increases in glutathione content under salinity stress. These may provide better protection against reactive oxygen species (ROS).  相似文献   

15.
Salinity is one of the major environmental factors limiting crop productivity. The effect of increasing salinity levels (0, 50, 100 mM NaCl) on growth, photosynthetic traits, leaf water potential, oxidative stress, enzymatic and non-enzymatic antioxidants was studied in Pusa Jai Kisan and SS2 cultivars of mustard (Brassica juncea L. Czern & Coss.) differing in ATP-sulfurylase activity at 30 days after sowing (DAS). The cultivar SS2 (low ATP-sulfurylase activity) accumulated higher content of Na+ and Cl in leaf than root. SS2 also showed greater content of thiobarbituric acid reactive substances (TBARS) and H2O2 and higher decrease in growth, photosynthetic traits and leaf water potential than Pusa Jai Kisan with increasing salinity levels. Contrarily, Pusa Jai Kisan (high ATP-sulfurylase activity) exhibited higher Na+ and Cl content in root than leaf, lower TBARS and H2O2 content and higher activity of catalase, ascorbate peroxidase and glutathione reductase. However, the activity of superoxide dismutase was greater in SS2 than Pusa Jai Kisan. Higher activity of ATP-sulfurylase in Pusa Jai Kisan resulted in increased content of glutathione, a reduced form of inorganic sulfur and an essential component of cellular antioxidant defense system. The lesser decrease in growth and photosynthesis in Pusa Jai Kisan was the result of lesser Na+ and Cl in leaf, higher turgidity and increased activity of antioxidant enzymes and glutathione content.  相似文献   

16.
Summary

Cadmium (Cd) is a metal pollutant that accumulates in cultivated soils and has detrimental consequences in terms of food safety. Lettuce (Lactuca sativa) can be characterised as having a high capacity to accumulate Cd in its tissues. An analysis of Cd tolerance and Cd accumulation was carried out using two varieties of lettuce (‘Divina’ and ‘Melina’). A wide range of CdCl2 concentrations was used (0.0, 0.1, 0.6, 3.0, and 15.0 µM CdCl2). The lowest concentration (0.1 µM CdCl2) stimulated growth, while the two highest concentrations resulted in a reduction in biomass. Cadmium concentrations were found to be twice as high in roots as in shoots. ‘Divina’ displayed lower concentrations of Cd than ‘Melina’ in nearly all treatments. A strong negative correlation was observed between Cd concentration and Cd tolerance in the roots and shoots (R2 > 0.87) of both ‘Melina’ and ‘Divina’. Lettuce grown in the presence of 15.0 µM CdCl2 had leaf Cd concentrations that were 100-fold higher than the legal maximum level for vegetable products marketed for human consumption, but showed no symptoms of dehydration, chlorosis, or necrosis. This result represents an important alert for lettuce consumers and growers.  相似文献   

17.
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   

18.
The aim of this study was to evaluate the effects of low molecular mass antioxidants and NaCl salinity on growth, ionic balance, proline, and water contents of ‘Zard’ olive trees under controlled greenhouse conditions. The experiment was carried out by spraying 2 mM of ascorbic acid (Asc) and 3 mM of reduced glutathione (GSH) on the plants that were treated with two salinity levels (0 and 100 mM NaCl) on their root medium. Plant growth parameters (leaf fresh weight, leaf dry weight, leaf number, total fresh weight, and total dry weight) were significantly improved by Asc compared with growth parameters in GSH and control plants. Higher concentrations of Na+ and Cl were observed in salt-stressed plants, while Na+ and Cl concentrations were decreased in the olive leaves that were sprayed with Asc. Salinity in the root zone caused a considerable decline in both K+ concentration and K/Na ratio. K+ concentration and K/Na ratio were significantly increased by application of Asc on plant leaves. Salinity caused an increase in electrolyte leakage (EL) compared with the control plants. Lowest EL and tissue water content (TWC) was obtained in Asc-sprayed plants, whereas TWC was increased in salt-stressed plants. Plants were subjected to salt stress and showed a higher relative water content (RWC) than the control plants. Salt stress induced proline accumulation in olive leaves. In conclusion, exogenous application of Asc is recommended to improve tolerance of olive plants under saline conditions.  相似文献   

19.
钙对盐胁迫下黄瓜幼苗抗氧化系统的影响   总被引:9,自引:3,他引:6  
以黄瓜(Cucumis sativus L.)品种‘津春2号’为材料,采用Hogland营养液栽培研究了Ca2+对盐(NaCl)胁迫下黄瓜幼苗体内可溶性蛋白和丙二醛(MDA)含量、超氧阴离子()产生速率以及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的影响。结果表明:盐胁迫处理下,黄瓜幼苗体内可溶性蛋白和MDA含量、产生速率以及抗氧化酶SOD、POD、CAT活性均高于对照;营养液中加入Ca2+(8 mmol • L-1)后,幼苗体内可溶性蛋白含量和SOD、POD、CAT抗氧化酶活性进一步提高,而MDA含量和的产生速率降低;而营养液缺钙处理下幼苗体内MDA和产生速率进一步提高,可溶性蛋白含量和抗氧化酶活性较盐胁迫降低。可见外源Ca2+可通过促进盐胁迫下黄瓜幼苗植株体内抗氧化酶活性的提高,降低膜脂过氧化水平,减缓盐胁迫对植株的伤害,从而增强对盐胁迫的适应性。  相似文献   

20.
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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