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1.
We examined the role of jasmonic acid (JA) in faba bean under cadmium (Cd) stress, which reduces the growth, biomass yield, leaf relative water content (LRWC) and pigment systems. Hydrogen peroxide (H2O2) and lipid peroxidation (malondialdehyde [MDA]) levels increased by 2.78 and 2.24-fold, respectively, in plants under Cd stress, resulting in enhanced electrolyte leakage. Following foliar application to Cd-treated plants, JA restored growth, biomass yield, LRWC and pigment systems to appreciable levels and reduced levels of H2O2, MDA and electrolyte leakage. Proline and glycine betaine concentrations increased by 5.73 and 2.61-fold, respectively, in faba bean under Cd stress, with even higher concentrations observed following JA application to Cd-stressed plants. Superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase levels rose by 87.47%, 130.54%, 132.55% and 37.79%, respectively, with Cd toxicity, with further enhancement of antioxidant activities observed following foliar application of JA. Accumulation of Cd in roots, shoots and leaves was also minimized by external supplementation of JA. In conclusion, JA mitigates the negative impacts of Cd stress in faba bean plants by inhibiting the accumulation of Cd, H2O2 and MDA, and by enhancing osmolyte and antioxidant activities that reduce oxidative stress.  相似文献   

2.
To evaluate the response of some selected wheat cultivars to silicon application at different growth stages under drought stress, an experiment was carried out in the greenhouse of College of Agriculture, Shiraz University, Iran, during 2012 using a completely randomized factorial design with four replications. Experimental treatments included drought stress (100% F.C. as control and 40% F.C. as drought) and foliar application of 6 mM sodium silicate (control, application at mid tillering stage, at anthesis stage, and application at tillering + anthesis stages) and wheat cultivars (Sirvan and Chamran, relatively drought-tolerant, and Shiraz and Marvdasht, drought-sensitive cultivars). Drought stress significantly reduced chlorophyll content, leaf area, relative water content, grains per spike, 1000-grain weight, grain yield and biomass of all wheat cultivars. Furthermore, drought stress increased electrolyte leakage of the flag leaves of all cultivars. In contrast, foliar-applied silicon significantly increased these parameters and reduced electrolyte leakage. Furthermore, highest positive influence of silicon application was observed at combined use of silicon both at the tillering + anthesis stages in wheat plants under both stress and non-stress conditions. Significant differences were found in physiological responses among wheat cultivars. The drought tolerant cultivars (Sirvan and Chamran) had significantly higher growth and yield than those of drought sensitive cvs. Shiraz and Marvdasht under drought stress. In conclusion, foliar application of silicon especially at the tillering + anthesis stages was very effective in promoting resistance in wheat plants to drought conditions by maintaining cellular membrane integrity and relative water content, and increasing chlorophyll content.  相似文献   

3.
A sand culture experiment was carried out to study the effects of sulfur deprivation on heat stress tolerance of two cluster bean (Cymopsis tetragonoloba L. Taub) cultivars (GC-1 and Pusa Nau Bahar (PNB)). Three weeks old sulfur-starved and sulfur-supplemented plants were subjected to heat stress (45°C/35°C) treatment for 24 h. Total dry weight, chlorophyll content, Chlorophyll a:b ratio, electrolyte leakage, malondialdehyde (MDA) accumulation, H2O2 content, sugar, glucose-6-phosphate (G-6-P), fructose-6-phosphate (F-6-P), ascorbate and glutathione concentrations and antioxidant enzyme activity (superoxide dismutase (SOD) and catalase (CAT)) were monitored, at the end of the heat stress treatment. Heat stress enhanced and sulfur starvation depleted the contents of sugar metabolites, but the accumulation of sugar, G-6-P and F-6-P were not related with heat stress tolerance. Antioxidant enzyme activities of SOD and CAT were influenced significantly more by sulfur starvation than heat stress. The results showed that under heat stress, the addition of sulfur helps to mitigate the oxidative damage in both the cultivars. However, GC-1 was more heat tolerant as it was characterized by significantly higher total dry weight, chlorophyll content, ascorbate and glutathione content and lower H2O2, MDA, electrolyte leakage than PNB.  相似文献   

4.
The present study investigated the potential role of external salicylic acid (SA) in alleviating Arsenic (As) toxicity in sunflower leaves. The exposure of plants to 10 µM As inhibited biomass production and intensively increased the accumulation of As in both roots and leaves. The levels of some important parameters associated with oxidative stress, namely lipid peroxidation, electrolyte leakage, and hydrogen peroxide (H2O2) production were increased. SA application alleviated the negative effect of As on growth and led to decrease in oxidative injuries. Furthermore, SA application led to higher activity of catalase, ascorbate peroxidase, and glutathione peroxidase, and concomitantly decreased superoxide dismutase and guaiacol peroxidase activities. As important antioxidants, ascorbate and glutathione contents in sunflower leaves exposed to As were significantly decreased by SA treatment. These results reveal that SA is more effective in alleviating As toxicity at higher concentrations than that at lower concentrations.  相似文献   

5.
钙离子通过调节抗氧化酶活性保护NaCl对菊芋的毒害   总被引：7，自引：0，他引：7  
The ameliorative effect of external Ca^2＋ on Jerusalem artichoke （Helianthus tuberosus L.） under salt stress was studied through biochemical and physiological analyses of Jerusalem artichoke seedlings treated with or without 10 mol L^-1 CaCl2, 150 mmol L^-1 NaCl, and/or 5 mmol L^-1 ethylene-bis（oxyethylenenitrilo）-tetraacetic acid （EGTA） for five days. Exposure to NaC1 （150 mmol L^-1） decreased growth, leaf chlorophyll content, and photosynthetic rate of Jerusalem artichoke seedlings. NaC1 treatment showed 59% and 37% higher lipid peroxidation and electrolyte leakage, respectively, than the control. The activities of superoxide dismutase （SOD）, peroxidase （POD）, and catalase （CAT） were decreased by NaCl, indicating an impeded antioxidant defense mechanism of Jerusalem artichoke grown under salt stress. Addition of 10 mmol L^-1 CaCl2 to the salt solutions significantly decreased the damaging effect of NaC1 on growth and chlorophyll content and simultaneously restored the rate of photosynthesis almost to the level of the control. Ca^2＋ addition decreased the leaf malondialdehyde （MDA） content and electrolyte leakage from NaCl-treated seedlings by 47% and 24%, respectively, and significantly improved the activities of SOD, POD, and CAT in NaCl-treated plants. Addition of EGTA, a specific chelator of Ca2＋, decreased the growth, chlorophyll content, and photosynthesis, and increased level of MDA and electrolyte leakage from NaCl-treated plants and from the control plants. EGTA addition to the growth medium also repressed the activities of SOD, POD, and CAT in NaCl-treated and control seedlings. External Ca2＋ might protect Jerusalem artichoke against NaC1 stress by up-regulating the activities of antioxidant enzymes and thereby decreasing the oxidative stress.  相似文献   

6.
A 28-day pot (sand culture) experiment was carried to evaluate the effects of phosphorus (P) application in alleviating Cd phytotoxicity in wheat plants. Different levels of P (0, 10, and 20 kg ha?1) were applied without and with 100 µM Cd. The results showed that 100 µM Cd concentration decreased plant biomass, chlorophyll contents, gas exchange attributes, and mineral nutrients in wheat plants. Cadmium stress increased tissue Cd and H2O2 concentrations. The activities of superoxide dismutases (SOD), peroxidase (POD) enzymes, increased while the activities of catalase (CAT), ascorbic acid (AsA), α-tocopherol, and phenolics decreased under Cd stress. Phosphorus supply increased shoot biomass, leaf area, photosynthetic pigments, and mineral nutrients and decreased Cd and H2O2 concentrations in shoots. Phosphorus application improved antioxidant enzyme activities and gas exchange attributes which emerged as an important mechanism of Cd tolerance in wheat. We conclude that P application contributes to decreased Cd concentrations in wheat shoots and increased gas exchange attributes and antioxidant enzymes and could be implemented in a general scheme aiming at controlling Cd concentrations in wheat for sustained production of this important grain crop.  相似文献   

7.
We studied the effects of salinity stress on biomass production, photosynthesis, water relations, and activity of antioxidant enzymes in two cultivars of common bean (‘HRS 516’ and ‘RO21’). Seedlings were raised in nutrient solution supplemented with increasing concentrations of sodium chloride (NaCl) at 0, 50, and 100 mM. After 10 days of salinity treatment, the plants were sampled to determine the enzyme activity, protein content and dry biomass. Plant biomass and activities of most antioxidant enzymes were adversely affected by salinity stress. Leaf osmotic potential was found to be directly proportional to salt stress. The cultivar, ‘HRS 516’ accumulated less sodium (Na+) than ‘RO21’. Under salinity, superoxide dismutase (SOD) enzyme activity increased 3 folds in both bean cultivars (‘HRS 516’ and ‘RO21’) compared to other antioxidants (APX, CAT, and GR). While not neglecting other possible factors, photosynthesis and biomass remains reliable indicators of plant functioning in response to salinity stress.  相似文献   

8.
Abstract

Inoculation effect of arbuscular mycorrhizal fungi (AMF) on phosphorus (P) transfer from composted dung of cattle with a diet supplemented with powdered rock phosphate (RP) and their successive uptake by mung bean plants was assessed in alkaline soil. The efficacy of composted RP fed dung alone or/and in combination with AMF inoculums containing six different species were compared with SSP in six replicates per treatment in pots. The results showed that the association of AMF with composted RP fed dung had a positive effect on mung bean shoot (3.04?g) and root (2.62?g) biomass, chlorophyll (a, b), carotenoid contents and N (58.38?mg plant?1) and P (4.61?mg plant?1) uptake. Similarly, the percent roots colonization (56%) and nodulation of mung bean plant roots and their post-harvest soil properties were also improved by the inoculation of AMF together with composted RP fed dung. It is concluded that the combined application of AMF with composted RP fed dung has almost the same effect as SSP for improving mung bean plants growth and their nutrients uptake. Moreover, AMF inoculants can be used as a suitable biofertilizer in combination with locally available organic sources of fertilizers for improving P status and growth of plants in alkaline soils.  相似文献   

9.
采用水培试验方法研究不同浓度Se4+(0.8,1.6,2.4,3.2,4.0mg/L)对Cd2+(10,20mg/L)胁迫下绿豆幼苗超微弱发光及幼苗叶片中叶绿素、可溶性蛋白质和脯氨酸的影响。结果表明,随着胁迫时间延长,不同浓度Se4+对2种浓度Cd2+胁迫下绿豆幼苗的超微弱发光强度均呈现先升高后降低再升高的趋势,0.8,1.6mg/L的Se4+对2种浓度Cd2+胁迫下绿豆幼苗的超微弱发光强度均有促进作用,但是1.6mg/L浓度的Se4+对2种浓度Cd2+的缓解作用最佳。随着Se4+浓度的增加,2种浓度Cd2+胁迫下,绿豆幼苗叶片中叶绿素含量和可溶性蛋白质含量均呈现出先增加又减小的趋势,当Se4+浓度低于4.0mg/L时,叶绿素含量和可溶性蛋白质含量均高于单一Cd2+胁迫下叶绿素含量和可溶性蛋白质含量,且在Se4+浓度为1.6mg/L时达到最大。在10mg/L Cd2+胁迫下,随着Se4+浓度的增加,绿豆幼苗叶片中的脯氨酸含量先增加后减小,当Se4+浓度低于4.0mg/L时,脯氨酸含量高于单一Cd2+胁迫下脯氨酸含量,且Se4+浓度为1.6mg/L时脯氨酸含量达到最大;在20mg/L Cd2+胁迫下,随着Se4+浓度的增加,绿豆幼苗叶片中的脯氨酸含量逐渐降低,当Se4+浓度低于2.4mg/L时,脯氨酸含量高于单一Cd2+胁迫下脯氨酸含量,且Se4+的浓度为0.8mg/L时脯氨酸含量最大。研究表明在试验浓度范围内,Se4+浓度低于2.4mg/L时,对10,20mg/L Cd2+胁迫下的绿豆幼苗的毒害均有缓解作用,且浓度为1.6mg/L时缓解作用最佳。  相似文献   

10.
Salt stress has become a major menace to plant growth and productivity. The main goal of this study was to investigate the effect of inoculation with the arbuscular mycorrhizal fungi (AMF; Rhizophagus intraradices) in combination or not with plant growth‐promoting rhizobacteria (PGPR; Pseudomonas sp. (Ps) and Bacillus subtilis) on the establishment and growth of Sulla coronaria plants under saline conditions. Pot experiments were conducted in a greenhouse and S. coronaria seedlings were stressed with NaCl (100 mM) for 4 weeks. Plant biomass, mineral nutrition of shoots and activities of rhizosphere soil enzymes were assessed. Salt stress significantly reduced plant growth while increasing sodium accumulation and electrolyte leakage from leaves. However, inoculation with AMF, whether alone or combined with the PGPR Pseudomonas sp. alleviated the salt‐induced reduction of dry weight. Inoculation with only AMF increased shoot nutrient concentrations resulting in higher K+: Na+, Ca2+: Na+, and Ca2+: Mg2+ ratios compared to the non‐inoculated plants under saline conditions. The co‐inoculation with AMF and Pseudomonas sp. under saline conditions lowered shoot sodium accumulation, electrolyte leakage and malondialdehyde (MDA) levels compared to non‐inoculated plants and plants inoculated only with AMF. The findings strongly suggest that inoculation with AMF alone or co‐inoculation with AMF and Pseudomonas sp. can alleviate salt stress of plants likely through mitigation of NaCl‐induced ionic imbalance, thereby improving the nutrient profile.  相似文献   

11.
缺硼对绿豆叶片光合特性和碳水化合物含量的影响   总被引：4，自引：0，他引：4  
本试验以绿豆为指示植物,采用溶液培养法研究了缺硼对叶片光合功能和碳水化合物含量的影响,以明确缺硼是否影响光合作用进而影响作物生长。在绿豆第二片真叶出现后的第二天,一半植株供给 50 mol/L 硼（高硼）,另一半植株供给0.2 mol/L 硼（低硼）,在叶片生长过程中动态监测叶绿素含量、 气体交换和碳水化合物含量。结果表明,缺硼对叶片叶绿素含量没有影响,缺硼降低了光合速率（Pn）和气孔导度（Gs）,但对胞间二氧化碳浓度（Ci）没有影响; 缺硼提高了气孔限制率（Ls）。虽缺硼降低了Pn,但提高了叶片中可溶性糖,特别是葡萄糖和淀粉的含量。本研究结果表明缺硼对植物生长的影响并非是由于碳水化合物缺乏的缘故,而是因降低库活力导致了Pn的降低。  相似文献   

12.
Boron (B) is one of the essential nutrients for the growth of plants, but its high concentrations are toxic for plants. Thus, B toxicity is a big challenge in crop cultivation. Nitric oxide (NO) is a small signaling molecule that has cytoprotective roles in plants. We investigated whether exogenous sodium nitroprusside (SNP), which is a NO donor, may succeed to alleviate B-induced toxicity in wheat cultivars. Seedlings were grown for 10 days in a growth chamber at 25°C with 16 hr light–8 hr dark photo cycle. After high B application, the effects of SNP on growth parameters; electrolyte leakage (EL); changes in reactive oxygen species [contents of hydrogen peroxide (H2O2), malondialdehyde (MDA), and proline]; the activities of antioxidant enzymes [glutathione peroxidase (GSHPx), glutathione reductase (GR), and glutathione S-transferase (GST)] and nitrate reductase (NR); and low molecular weight organic acid (LMWOAs) contents and also chlorophyll and total carotenoid contents were investigated in both shoots and roots of two different wheat cultivars. All experiments were carried out in triplicate. 0.2 mM SNP application ameliorated the chlorophyll and total carotenoid contents, and growth parameters such as shoot length, root length, and fresh weight in both wheat cultivars exposed to B stress. SNP reduced the B-induced lipid peroxidation, EL, and proline and H2O2 content in wheat cultivars. SNP application also increased the activities of NR and antioxidant enzymes, including GSHPx, GR, and GST in wheat cultivars exposed to B toxicity. All of the tested LMWOAs including succinic, propionic, butyric, oxalic, formic, malic, malonic, and benzoic acids were increased by SNP treatment in the shoots and roots of both wheat cultivars exposed to B toxicity. In conclusion, results obtained from this study have demonstrated that interactive effects of SNP with B considerably reduced the toxic effects of B in wheat cultivars.  相似文献   

13.
钙对镉胁迫下玉米生长及生理特性的影响   总被引：59，自引：1，他引：59  
采用溶液培养试验 ,研究不同的钙和镉处理对玉米植株生长、叶绿素含量、硝酸还原酶和ATPase酶活性以及叶片中丙二醛含量、活性氧清除酶系统活性的影响。结果表明 ,根部未供钙或叶面喷施CaCl2时 ,加镉处理玉米根、地上部生物量降低 ,根冠比加大 ;而根部供钙 ,植株生长较好 ,生物量较高 ,根冠比相对较小。营养液中加镉 ,玉米植株中镉浓度显著增加 ,根部镉浓度明显比地上部高 ,根中镉约占 65%～ 78% ,地上部镉占到 22%～35%左右。根部供钙比未供钙处理 ,根中镉含量虽没有显著性差别 ,但地上部镉浓度明显较低。叶片喷施CaCl2 4次比喷施 2次处理 ,地上部镉浓度增加。供钙明显增加了玉米植株中钙浓度。未供钙的玉米叶片叶绿素含量下降 ,但叶绿素a/叶绿素b比基本不变 ;加镉处理 ,玉米叶片叶绿素a、叶绿素b及叶绿素总量下降更甚 ,叶绿素a/叶绿素b比升高 ;叶面喷施CaCl2 ,叶绿素含量也较低。前期和后期根部供钙处理 ,叶绿素下降程度有所缓解。而根部一直供钙 ,玉米叶片中叶绿素a、叶绿素b和叶绿素总量明显提高。镉抑制了玉米植株叶片硝酸还原酶活性、ATPase活性 ;根中ATPase活性以及活性氧清除酶系统超氧化物歧化酶 (SOD)、愈创木酚过氧化物酶 (Gua POD)、抗坏血酸过氧化物酶 (AsA POD)、过氧化氢酶 (CAT)受镉的诱导而增加，叶片中丙二醛(MDA)含量升高。与未供应钙加镉处理相比，根部供钙加镉处理的玉米叶片硝酸还原酶活性、ATPase活性显著增加，也明显减轻了镉对根中ATPase活性、叶片中丙二醛含量、活性氧清除酶系统SOD，POD，CAT 活性的诱导效应。间隔供钙，在一定程度上缓解了镉的毒害，但是叶片喷施CaCl2，对减轻镉毒害无明显效果。因此在本试验条件下，根部供钙对缓解玉米镉毒害有重要作用。关键词:钙；镉；玉米；生理特性  相似文献   

14.
Cotton (Gossypium hirsutum L.) is a well-known and economically most beneficial crop worldwide while nickel (Ni) toxicity is a widespread problem in crops grown on Ni-contaminated soils. We investigated the response of silicon (Si) in cotton under Ni stress with respect to growth, biomass, gas exchange attributes, enzymatic activities, and Ni uptake and accumulation. For this, plants were grown in hydroponics for 12 weeks with three levels of Ni (0, 50, and 100 µM) in the presence or absence of 1 mM Si. Results showed that Ni significantly reduced the plant growth, biomass, gas exchange attributes, and pigment contents while Si application mitigated these adverse effects under Ni stress. Nickel stress significantly decreased antioxidant enzymes’ activities while increased malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage (EC) in leaves and roots. The application of Si enhanced the activities of antioxidant enzymes and reduced MDA, H2O2, and EC in plants. Nickel application significantly increased Ni concentration and accumulation in leaf, stem, and roots while Si application significantly decreased Ni in these plant parts. The present study indicates that Si could improve cotton growth under Ni stress by lowering Ni uptake and reactive oxygen species (ROS) and by increasing antioxidant enzymes activities.  相似文献   

15.
A tub experiment was conducted to assess the effect of exogenously applied trehalose (0, 10, and 20 mM) on various attributes of two rice cultivars (Bas-385 and Bas-2000) under salt stress (0, 50, 100, and 150 mM). Salinity decreased growth, gas exchange characteristics, shoot and root potassium (K+) ions, hydrogen peroxide (H2O2), total soluble proteins, activity of catalase (CAT), and yield attributes, while it increased chlorophyll contents, shoot and root sodium (Na+) and calcium (Ca2+), malondialdehyde (MDA), glycinebetain (GB), free proline, and peroxidase (POD) activity. Foliar-applied trehalose improved growth attributes, net photosynthetic rate, GB, total soluble proteins, superoxide dismutase (SOD) and yield. Yield was not obtained at 150 mM salt stress. The rice cultivar Bas-2000 showed better performance with respect to gas exchange attributes and activities of enzymatic antioxidants. Overall, varying levels of foliar-applied trehalose proved to be effective in ameliorating adverse effects of salt stress on rice.  相似文献   

16.
The ability of selenium (Se) to counteract salt inhibitory effects in crop plants, especially in tomato, is still poorly documented. In order to examine the impact of Se addition on the growth, some biochemical parameters related to osmotic adjustment and antioxidant defense of salt-stressed tomato, a two-factorial experiment was conducted in a greenhouse. The plants were supplied with NaCl (0, 25, or 50 mM) and Se (0, 5, or 10 μM), individually or simultaneously. The results showed that salinity had a deleterious impact on plant biomass and physiological parameters studied. The application of Se alleviated this adverse effect by improving the integrity of cell membranes and by increasing leaf relative water content under stress conditions. Moreover, the application of 10 μM Se significantly increased the photosynthetic pigments concentration under salt stress. Salt stress also caused an inhibition of catalase activity, but its activity was restored in the presence of Se. The free radical scavenging activity significantly increased in plants subjected to 25 mM NaCl and supplied with 5 µM Se, compared to NaCl-alone treatment. Both physiological and biochemical results indicate that 10 µM Se treatment can increase plant performance under salt stress, especially under high NaCl concentration.

Abbreviations: CAT: catalase; Chl: chlorophyll; DPPH: 2,2-diphenyl-1-picrylhydrazyl; DW: dry weight; FW: fresh weight; POD: peroxidase; REL: relative electrolyte leakage; RWC: relative water content; free radical scavenging activity (FRSA); TW: turgid weight  相似文献   


17.
The effects of salt stress on plant growth parameters, lipid peroxidation and some antioxidant enzyme activities [superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), peroxidase (POD, EC 1.11.1.7), glutathione reductase (GR; EC EC 1.6.4.2) and ascorbate peroxidase (APX, EC 1.11.1.11) activity] were studied in the leaves of mustard. Plants were exposed to two different concentrations of NaCl stress (100 and 150 mM) for 45 days and were sprayed with GA3 (75 ml pot?1, conc. 75 mg l?1) once a week. Salt stress resulted in decrease in the growth and biomass yield of mustard but the exogenous application of GA3 enhanced these parameters significantly. Application of GA3 counteracted the adverse effects of NaCl salinity on relative water content, electrolyte leakage and chlorophyll (Chl) content. GA3 was sufficient to attenuate partially the stimulatory effect of NaCl supply on proline and glycinebetaine biosynthesis. GA3 reduced lipid peroxidation in the leaves, which was increased during salt stress. The activity of all the antioxidant enzymes was increased significantly during salt stress in mustard. The exogenous application of GA3 decreased the enzyme activity. The results of the present study indicate that usage of GA3 reduces the harmful effects of salinity and increases resistance to salinity in mustard plant.  相似文献   

18.
Siderophores produced by Pseudomonas sp. may be used by the bacteria (homologously) or in effecting plant nutrition (heterologously). The problem of iron non-availability particularly in calcareous soils may be overcome by incorporation of siderophore producing strains of fluorescent psuedomonads (FLPs). Siderophore producing bacterium Pseudomonas strain GRP3 was used in a pot experiment to assess the role of microbial siderophores in the iron nutrition of mung bean (Vigna radiataL. Wilzeck) using Fe-citrate, Fe-EDTA and Fe(OH)3 in different concentrations with Hoagland's solution. After 45 days, the plants showed a reduction of chlorotic symptoms and enhanced chlorophyll level in GRP3 bacterized plants. Bacterization with GRP3 increased peroxidase activity and lowered catalase activity in roots. In 10 μM Fe-citrate alongwith GRP3 treatment, chlorophyll a, chlorophyll b and total chlorophyll contents increased significantly by 34, 48 and 39%, respectively, compared to the control. Peroxidase activity in the same treatment was increased by 82% whereas catalase activity decreased by 33%. There was also a significant increase in total and physiologically available iron. A closely similar pattern was observed in chlorophyll content and peroxidase activity in Fe-EDTA and Fe(OH)3 treated plants; catalase activity was an exception. The data suggests operation of heterologous siderophore uptake system in mung bean in presence of GRP3. Such siderophore producing system has the potential of improving iron availability to plants and reduce fertilizer usage.  相似文献   

19.
Sunflower (Helianthus annuus L.) is an important oilseed crop with clear sensibility to salt stress. In this study, we evaluated silicon (Si) effect on the nitrogen metabolism and antioxidant enzyme activity in sunflower plants subjected to salinity. A 4 × 4 factorial arrangement of treatments in a completely randomized design with four replicates was used, consisting of four concentrations of Si (0.0; 1.0; 1.5; and 2.0 mM) and four concentrations of NaCl (0; 50; 100; and 150 mM) in the nutrient solution. The salinity reduced the nitrate content, but the increasing Si concentration in the medium improved the nitrate uptake, leading this ion to accumulate in salt-stressed plants, particularly in the roots. The nitrate reductase activity and the proline and soluble N-amino contents were also significantly increased by Si in salt conditions. The salinity increased electrolyte leakage and reduced the activity of enzymes superoxide dismutase, ascorbate peroxidase and catalase in sunflower plants, but these decreases were reversed by Si at 2 mM, thus alleviating the effects of salinity on these variables. We conclude that Si is able to positively modulate nitrogen metabolism and antioxidant enzyme activities in sunflower plants in order to alleviate the harmful effects of salinity.  相似文献   

20.
大气CO2浓度升高对绿豆生长发育与产量的影响   总被引：2，自引：1，他引：2  
研究大气CO2浓度升高对绿豆影响,有助于人们了解未来气候变化后绿豆生产的变化,以提前采取必要的应对措施趋利避害.本研究利用FACE(Free Air CO2 Enrichment)系统在大田条件进行了绿豆生长发育及产量受CO2浓度升高影响的试验.结果表明:大气CO,浓度升高后,绿豆叶面积、株高、节数、茎粗增加;倒数第一...  相似文献   

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