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1.
Hydrogen peroxide pretreatment of roots enhanced oxidative stress response of tomato under cold stress 总被引:1,自引:0,他引:1
Özlem Darcansoy İşeri Didem Aksoy Körpe Feride Iffet Sahin Mehmet Haberal 《Acta Physiologiae Plantarum》2013,35(6):1905-1913
In the view of physiological role of H2O2, we investigated whether exogenous H2O2 application would affect short-term cold response of tomato and induce acclimation. Pretreatments were performed by immersing roots into 1 mM H2O2 solution for 1 h when transferring seedlings from seedling substrate to soil (acclimated group). Cold stress (3 °C for 16 h) caused significant reduction in relative water content (RWC) of control and non-acclimated (distilled water treated) groups when compared with unstressed plants. H2O2 promoted maintenance of relatively higher RWC under stress. Anthocyanin level in leaves of acclimated plants under cold stress was significantly higher than that of unstressed control and non-acclimated plants. Malondialdehyde (MDA) levels demonstrated low temperature induced oxidative damage to control and non-acclimated plants. MDA remained around unstressed conditions in acclimated plants, which demonstrate that H2O2 acclimation protected tissues against cold induced lipid peroxidation. H2O2 acclimation caused proline accumulation in roots under cold stress. Ascorbate peroxidase (APX) activity in roots of cold stressed and unstressed H2O2 acclimated plants increased when compared with control and non-acclimated plants, with highest increase in roots of acclimated plants under cold stress. CAT levels in roots of acclimated plants also increased, whereas levels remained unchanged in unstressed plants. Endogenous H2O2 levels significantly increased in roots of control and non-acclimated plants under cold stress. On the other hand, H2O2 content in roots of acclimated plants was significantly lower than control and non-acclimated plants under cold stress. The results presented here demonstrated that H2O2 significantly enhanced oxidative stress response by elevating the antioxidant status of tomato. 相似文献
2.
Abscisic acid improves drought tolerance of triploid bermudagrass and involves H2O2- and NO-induced antioxidant enzyme activities 总被引:1,自引:0,他引:1
Drought is a major limiting factor for turfgrass growth. Protection of triploid bermudagrass against drought stress by abscisic acid (ABA) and its association with hydrogen peroxide (H2O2) and nitric oxide (NO) were investigated. ABA treatment increased relative water content, decreased ion leakage and the percentage of dead plants significantly under drought stress. Superoxide dismutase (SOD) and catalase (CAT) activities increased in both ABA-treated and control plants, but more in ABA-treated plants, under drought stress. Malondialdehyde, an indicator of plant lipid peroxidation, was lower in ABA-treated plants than in control plants, indicating that ABA alleviated drought-induced oxidative injury. ABA treatment increased H2O2 and NO contents. ABA-induced SOD and CAT activities could be blocked by scavengers of H2O2 and NO, and inhibitors of H2O2 and NO generation. The results indicated that H2O2 and NO were essential for ABA-induced SOD and CAT activities. Both H2O2 and NO could induce SOD and CAT activities individually. SOD and CAT induced by H2O2 could be blocked by scavenger of NO and inhibitors of NO generation, while SOD and CAT induced by NO could not be blocked by scavenger of H2O2 and inhibitor of H2O2. The results revealed that ABA-induced SOD and CAT activities were mediated sequentially by H2O2 and NO, and NO acted downstream of H2O2. 相似文献
3.
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
4.
Madhuri Sridharamurthy Amanda Kovach Yang Zhao Jian-Kang Zhu H. Eric Xu Kunchithapadam Swaminathan Karsten Melcher 《PloS one》2014,9(12)
Due to its ability to be rapidly generated and propagated over long distances, H2O2 is an important second messenger for biotic and abiotic stress signaling in plants. In response to low water potential and high salt concentrations sensed in the roots of plants, the stress hormone abscisic acid (ABA) activates NADPH oxidase to generate H2O2, which is propagated in guard cells in leaves to induce stomatal closure and prevent water loss from transpiration. Using a reconstituted system, we demonstrate that H2O2 reversibly prevents the protein phosphatase HAB1, a key component of the core ABA-signaling pathway, from inhibiting its main target in guard cells, SnRK2.6/OST1 kinase. We have identified HAB1 C186 and C274 as H2O2-sensitive thiols and demonstrate that their oxidation inhibits both HAB1 catalytic activity and its ability to physically associate with SnRK2.6 by formation of intermolecular dimers. 相似文献
5.
Effect of exogenous hydrogen peroxide on enzymatic and nonenzymatic antioxidants in leaves of young pea plants treated with paraquat 总被引:1,自引:0,他引:1
Irina Moskova Dessislava Todorova Vera Alexieva Sergei Ivanov Iskren Sergiev 《Plant Growth Regulation》2009,57(2):193-202
The effects of exogenously applied hydrogen peroxide on the antioxidant system of pea plants were investigated. Ten-day-old
pea seedlings were sprayed with 2.5 mM H2O2 and 24 h later with 0.2 mM PQ. Samples were taken 0, 2 and 5 h after the start of illumination. The protective effect of
H2O2 was evaluated by monitoring of parameters related to the damage caused by PQ. The treatment with PQ led to a severe leakage
of electrolytes from leaf tissues. Malondialdehyde level increased in PQ treated plants, but remained unchanged in H2O2 pre-treated ones after 5 h of illumination. Increased catalase and glutathione-S-transferase activity was observed in pea
plants treated with H2O2 and PQ. Ascorbate peroxidase activity decreased significantly after paraquat application, but pre-treatment with H2O2 prevented ascorbate peroxidase inhibition to some extent. Increased guaiacol peroxidase activity was detected after H2O2 application. PQ application caused a drastic decline in the levels of thiol-group bearing compounds, reduced glutathione
and ascorbate, while the quantity of oxidized glutathione and dehydroascorbate were increased. The results presented on changes
in enzymatic and nonenzymatic antioxidants suggest that preliminary H2O2 application to pea plants treated with PQ, alleviates the toxic effects of the herbicide. 相似文献
6.
Takanori Maruta Takahiro Inoue Masahiro Noshi Masahiro Tamoi Yukinori Yabuta Kazuya Yoshimura Takahiro Ishikawa Shigeru Shigeoka 《Biochimica et Biophysica Acta (BBA)/General Subjects》2012
Background
Reactive oxygen species (ROS) are not only cytotoxic compounds leading to oxidative damage, but also signaling molecules for regulating plant responses to stress and hormones. Arabidopsis cytosolic ascorbate peroxidase 1 (APX1) is thought to be a central regulator for cellular ROS levels. However, it remains unclear whether APX1 is involved in plant tolerance to wounding and methyl jasmonate (MeJA) treatment, which are known to enhance ROS production.Methods
We studied the effect of wounding and MeJA treatment on the levels of H2O2 and oxidative damage in the Arabidopsis wild-type plants and knockout mutants lacking APX1 (KO-APX1).Results
The KO-APX1 plants showed high sensitivity to wounding and MeJA treatment. In the leaves of wild-type plants, H2O2 accumulated only in the vicinity of the wound, while in the leaves of the KO-APX1 plants it accumulated extensively from damaged to undamaged regions. During MeJA treatment, the levels of H2O2 were much higher in the leaves of KO-APX1 plants. Oxidative damage in the chloroplasts and nucleus was also enhanced in the leaves of KO-APX1 plants. These findings suggest that APX1 protects organelles against oxidative stress by wounding and MeJA treatment.General significance
This is the first report demonstrating that H2O2-scavenging in the cytosol is essential for plant tolerance to wounding and MeJA treatment. 相似文献7.
《Journal of Plant Interactions》2013,8(1):550-558
Salvinia natans L. response to hydrogen peroxide (H2O2) induced oxidative stress through physiological activities was evaluated. The plants were incubated with varying concentrations (0, 50, 100 µM) of H2O2 and 100 µM of H2O2 supplemented with 1 mM putrescine (Put) in hydroponic culture. This is observed with the decline in proline content and its biosynthetic enzymes viz. γ-glutamyl kinase and γ-glutamyl phosphate reductase activity. Protein carbamylated derivative by protein oxidation was another trait for oxidative damages by H2O2. The antioxidative enzymes like guaiacol peroxidase (GPX), glutathione reductase (GR), and catalase (CAT) recorded to express through in-gel staining with the H2O2 exposure. On nuclear level, plants were sensitive to H2O2 where the DNA disintegration was studied with comet assay and maximum comet tail observed at 100 µM H2O2 treatment. Application of Put reduced the generation of protein oxidation and comet tail length as well as moderated the enzyme activity as revealed through in-gel staining. 相似文献
8.
Gerd P. Bienert 《生物化学与生物物理学报:生物膜》2006,1758(8):994-1003
Hydrogen peroxide (H2O2) belongs to the reactive oxygen species (ROS), known as oxidants that can react with various cellular targets thereby causing cell damage or even cell death. On the other hand, recent work has demonstrated that H2O2 also functions as a signalling molecule controlling different essential processes in plants and mammals. Because of these opposing functions the cellular level of H2O2 is likely to be subjected to tight regulation via processes involved in production, distribution and removal. Substantial progress has been made exploring the formation and scavenging of H2O2, whereas little is known about how this signal molecule is transported from its site of origin to the place of action or detoxification. From work in yeast and bacteria it is clear that the diffusion of H2O2 across membranes is limited. We have now obtained direct evidence that selected aquaporin homologues from plants and mammals have the capacity to channel H2O2 across membranes. The main focus of this review is (i) to summarize the most recent evidence for a signalling role of H2O2 in various pathways in plants and mammals and (ii) to discuss the relevance of specific transport of H2O2. 相似文献
9.
《Free radical biology & medicine》2011,50(12):2040-2048
Hydrogen peroxide (H2O2) has important messenger and effector functions in the plant and animal kingdom. Phagocytes produce H2O2 to kill pathogens, and epithelial cells of large airways have also been reported to produce H2O2 for signaling and host defense purposes. In this report, we show for the first time that urothelial cells produce H2O2 in response to a calcium signal. Using a gene-deficient mouse model we also demonstrate that H2O2 is produced by the NADPH oxidase Duox1, which is expressed in the mouse urothelium. In contrast, we found no evidence for the expression of lactoperoxidase, an enzyme that has been shown to cooperate with Duox enzymes. We also found that specific activation of TRPV4 calcium channels elicits a calcium signal and stimulates H2O2 production in urothelial cells. Furthermore, we detected altered pressure responses in the urinary bladders of Duox1 knockout animals. Our results raise the possibility that mechanosensing in epithelial cells involves calcium-dependent H2O2 production similar to that observed in plants. 相似文献
10.
Anne Herbst Viraj Ranawakage Takashi Asaeda Hendrik Schubert 《Phycological Research》2022,70(1):57-65
The immediate effect of zinc (Zn) and hydrogen peroxide (H2O2) in Chara braunii was analyzed in short-time exposure experiments. The exposure concentrations were 12.3, 18.4, and 24.5 μmol L?1 H2O2, 12, 60, and 120 mg L?1 Zn, and 12.3 μmol L?1 H2O2 + 12 mg L?1 Zn, 12.3 μmol L?1 H2O2 + 60 mg L?1 Zn, and 18.4 μmol L?1 H2O2 + 12 mg L?1 Zn. The stress response of C. braunii was analyzed by measuring photosynthetic photosystem II activity, chlorophyll a and b and carotenoid contents, the H2O2 concentration, and antioxidant enzyme activities of ascorbic peroxidase, catalase, and guaiacol peroxidase. The short-term addition of Zn reduced pigment contents in C. braunii. Chlorophyll a and b and carotenoid contents in H2O2-exposed C. braunii were as high as in control plants. Photosynthesis was reduced in H2O2-treated C. braunii and the short-term addition of Zn did not affect the electron transport rate. H2O2 concentration and antioxidant enzyme activities in C. braunii were not significantly different between control and exposed plants. Trends of enzymatic adaptation were described: the H2O2-induced stress response was characterized by increased antioxidant enzyme activities, whereas Zn inactivated catalase in C. braunii. 相似文献
11.
Hydrogen peroxide produced by NADPH oxidase: a novel downstream signaling pathway in melatonin‐induced stress tolerance in Solanum lycopersicum
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The beneficial effects of melatonin on abiotic stress have been demonstrated in several plants. However, little is known about the signal transduction pathway of melatonin involved in the plant stress response. Here, we manipulated the melatonin levels in tomato plants through a chemical approach. The roles of melatonin in stress tolerance were studied by assessing the symptoms, chlorophyll fluorescence and stress‐responsive gene expression. Moreover, both chemical and genetic approaches were used to study the roles of hydrogen peroxide (H2O2) in melatonin‐induced signal transduction in tomato plants. We found that melatonin activates NADPH oxidase (RBOH) to enhance H2O2 levels by reducing its S‐nitrosylation activity. Furthermore, melatonin‐induced H2O2 accumulation was accompanied by obtainable stress tolerance. Inhibition of RBOH or chemical scavenging of H2O2 significantly reduced the melatonin‐induced defense response, including reduced expression of several stress‐related genes (CDPK1, MAPK1, TSPMS, ERF4, HSP80 and ERD15) and reduced antioxidative enzyme activity (SOD, CAT and APX), which were responsible for the stress tolerance. Collectively, these results revealed a novel mechanism in which RBOH activity and H2O2 signaling are important components of the melatonin‐induced stress tolerance in tomato plants. 相似文献
12.
Martha Elena Mora-Herrera Humberto López-Delgado Alberto Castillo-Morales Christine H. Foyer 《Physiologia plantarum》2005,125(4):430-440
The effects of salicylic acid (SA) and hydrogen peroxide (H2O2) on freezing tolerance were studied in two potato (Solanum tuberosum) cultivars (Alpha and Atlantic) that differ in cold sensitivity, Alpha being more tolerant to freezing than Atlantic. Lowest freezing survival rates were observed in 4-week-old plants. Freezing treatments consisting of exposure to 6° C for 4 h in the dark were applied 24 h after plants had been transferred from in vitro culture to soil. Catalase activity and H2O2 were estimated at the following harvest points: stage (a) 4-week-old in vitro plants treated with either 0.1 mM SA or 5 mM H2O2; stage (b) as in (a) but 24 h following transfer to soil prior to freezing treatment; stage (c) as in (b) but measured 15 days after a 4-h freezing treatment. The results show that (1) SA induced freezing tolerance in both cultivars; (2) SA inhibited ascorbate peroxidase activities in both cultivars at all harvest points but inhibited catalase activities in only at stage (a); (3) SA induced H2O2 accumulation only in Atlantic at stage (a); (4) H2O2 enhanced shoot catalase activities in Atlantic at stages (a) and (b) whereas this treatment had no effect on shoot catalase activities in Alpha; (5) H2O2 treatment induced freezing tolerance in Atlantic, even though shoot catalase activities were lower than those of the controls following exposure to freezing temperatures. We conclude that SA does not always lead to H2O2 accumulation even though catalase and ascorbate peroxidase activities are decreased as a result of the treatment. Moreover, H2O2 accumulation is not always associated with the induction of freezing tolerance, for example at stage (a) where SA-induced tolerance in Alpha was not accompanied by H2O2 accumulation. H2O2 was able to induce freezing tolerance only in Atlantic, even though H2O2 accumulated in both cultivars following this treatment. 相似文献
13.
Enhanced tolerance to light stress of transgenic Arabidopsis plants that express the codA gene for a bacterial choline oxidase 总被引:9,自引:0,他引:9
Alia Kondo Y Sakamoto A Nonaka H Hayashi H Saradhi PP Chen TH Murata N 《Plant molecular biology》1999,40(2):279-288
Arabidopsis thaliana was transformed with the codA gene from Arthrobacter globiformis. This gene encodes choline oxidase, an enzyme that converts choline to glycinebetaine. The photosynthetic activity, monitored in terms of chlorophyll fluorescence, of transformed plants was more tolerant to light stress than that of wild-type plants. This enhanced tolerance to light stress was caused by acceleration of the recovery of the photosystem II (PS II) complex from the photo-inactivated state. The transformed plants synthesized glycinebetaine, but no changes were detected in the relative levels of membrane lipids or in the relative levels of fatty acids in the various membrane lipids. Transformation with the codA gene increased levels of H2O2, a by-product of the reaction catalyzed by choline oxidase, by only 50% to 100% under stress or non-stress conditions. The activity of ascorbate peroxidase and, to a lesser extent, that of catalase in transformed plants were significantly higher than in the wild-type plants. These observations suggest that H2O2 produced by choline oxidase in the transformed plants might have stimulated the expression of H2O2 scavenging enzymes, with resultant maintenance of the level of H2O2 within a certain limited range. It appears that glycinebetaine produced in vivo, but not changes in membrane lipids or in the level of H2O2, protected the PS II complex in transformed plants from damage due to light stress. 相似文献
14.
Liuqiang Wang Zhen Li Chao Wang Deyin Wang Yucheng Wang Mengzhu Lu 《Journal of Plant Biology》2017,60(6):548-557
Peroxiredoxins (Prxs) are ubiquitous thiol-specific antioxidant enzymes that are critically involved in cell defense and protect cells from oxidative damage. In this study, a putative Type II Prx (ThPrx1) was identified and characterized from Tamarix hispida. The expression of ThPrx1 is highly induced in response to hydrogen peroxide (H2O2) and methyl viologen (MV) stresses. When expressed ectopically, ThPrx1 showed enhanced tolerance against oxidative stress in yeast and Arabidopsis. In addition, transgenic Arabidopsis plants overexpressing ThPrx1 displayed improved seedling survival rates and increased root growth and fresh weight gain under H2O2 and MV treatments. Moreover, transgenic Arabidopsis plants showed decreased accumulation of H2O2, superoxide (O2??) and malondialdehyde (MDA), increased superoxide dismutase (SOD) activity compared to wild-type (WT) plants under oxidative stress. Moreover, transgenic plants maintained higher photosynthesis efficiency and lower electrolyte leakage rates than that of WT plants under stress conditions. These results clearly indicated that ThPrx1 plays an important role in cellular redox homeostasis under stress conditions, leading to the maintenance of membrane integrity and increased tolerance to oxidative stress. 相似文献
15.
16.
Hydrogen peroxide (H2O2) in minute quantity serves as a signalling molecule. However, the role of H2O2 in combination with brassinosteroids (stress regulators) in plants under toxic levels of copper, is poorly understood. With an aim to explore and elaborate their role in plants subjected to abiotic stress, the surface sterilized seeds of mung bean (Vigna radiata) were sown in earthen pots filled with soil and manure enriched with different levels of Cu2+ (50 or 100 mg kg?1 of soil) and allowed to grow under natural environmental conditions. At 15 and 20 days stage, the plants were sprayed with H2O2 (2.5 mM) and/or 28-homobrassinolide (HBL, 10?5 mM), respectively. At 45 days stage, the analysis of the plants revealed that the presence of copper in the soil caused a significant decrease in growth characteristics, activity of carbonic anhydrase and nitrate reductase, relative water content, chlorophyll content and the rate of photosynthesis whereas, the activity of antioxidant enzymes (catalase, peroxidase and superoxide dismutase) and the proline accumulation in leaves increased in Cu stressed plants. However, the exogenously applied HBL and/or H2O2, in the absence of Cu-stress strongly favoured the growth, photosynthetic parameters and also improved the activity of antioxidant enzymes and the proline content. Furthermore, the combined application of HBL and H2O2 to the foliage of the stressed plants neutralized the toxic impact of all copper regimes. Therefore, we are of the opinion that these chemicals somehow maintained the homeostasis of the metal in the plants that exhibit healthy growth. 相似文献
17.
以烟草((Nicotiana tabacum,品种CF90NF)为寄主,苗期接种丛枝菌根(AM)真菌摩西球囊霉(Glomus mosseae,G.m),测定G.m与烟草共生过程中烟草根部H2O2含量以及多胺氧化酶(PAO)和过氧化物酶(POD)活性;研究外源H2O2对G.m侵染烟草的影响以及H2O2清除剂和合成抑制剂对烟草侧根H2O2含量及烟草侧根和菌丝中H2O2荧光强度的影响,以探究H2O2在AM真菌侵染烟草过程中的作用。结果表明,接种G.m 20d后烟草侧根中出现H2O2含量的猝发,一定浓度的外源H2O2促进G.m对烟草的侵染,而H2O2清除剂抗坏血酸(AsA)显著削弱烟草侧根和菌丝中的H2O2荧光强度,降低G.m对烟草的侵染率,表明H2O2参与G.m与烟草共生过程;在G.m与烟草共生过程中,PAO和POD活性显著升高,PAO抑制剂二氨基十二烷(DADD)和POD抑制剂水杨羟肟酸(SHAM)显著降低烟草侧根中H2O2荧光强度,对菌丝中H2O2荧光强度无显著影响,表明烟草根部和G.m均可产生H2O2,PAO和POD参与烟草侧根中H2O2的合成,菌丝中可能存在其他来源的H2O2。 相似文献
18.
Xiuli Hu Wei Wang Chunqi Li Jianhua Zhang Fan Lin Aying Zhang Mingyi Jiang 《Plant Growth Regulation》2008,55(3):183-198
Here we examined whether Ca2+/Calmodulin (CaM) is involved in abscisic acid (ABA)-induced antioxidant defense and the possible relationship between CaM
and H2O2 in ABA signaling in leaves of maize (Zea mays L.) plants exposed to water stress. An ABA-deficient mutant vp5 and its wild type were used for the experimentation. We found that water stress enhanced significantly the contents of CaM
and H2O2, and the activities of chloroplastic and cytosolic superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione
reductase (GR), and the gene expressions of the CaM1, cAPX, GR1 and SOD4 in leaves of wild-type maize. However, the increases mentioned above were almost arrested in vp5 plants and in the wild-type plants pretreated with ABA biosynthesis inhibitor tungstate (T), suggesting that ABA is required
for water stress-induced H2O2 production, the enhancement of CaM content and antioxidant defense. Besides, we showed that the up-regulation of water stress-induced
antioxidant defense was almost completely blocked by pretreatment with Ca2+ inhibitors, CaM antagonists and reactive oxygen (ROS) manipulators. Moreover, the analysis of time course of CaM and H2O2 production under water stress showed that the increase in CaM content preceded that of H2O2. These results suggested that Ca2+/CaM and H2O2 were involved in the ABA-induced antioxidant defense under water stress, and the increases of Ca2+/CaM contents triggered H2O2 production, which inversely affected the contents of CaM. Thus, a cross-talk between Ca2+/CaM and H2O2 may play a pivotal role in the ABA signaling. 相似文献
19.
Qiang Xu Xin Xu Yan Zhao Kun Jiao Stephen J. Herbert Lin Hao 《Plant Growth Regulation》2008,54(3):249-259
This study investigates the role of salicylic acid (SA), hydrogen peroxide (H2O2) and calcium chloride (CaCl2) singly or in combination, in inducing naked oat plant tolerance to sodium chloride (NaCl). Two-week-old naked oat plants
were pretreated with both single and double of 0.5 mM SA, 0.5 mM H2O2 and 5 mM CaCl2 by adding them to the culture solution for 24 h. At the end of the pretreatment, the plants were subjected to 200 mM NaCl
exposure for 7 days. Data were collected on plant biomass, H2O2 level, antioxidant enzyme activity, non-enzymatic antioxidant content and malondialdehyde (MDA) content. Results showed that
exposure to salt significantly inhibited plant growth, and the shoot and root dry weights were reduced 47.5% and 63.4%, and
the H2O2 levels elevated 5.8 and 2.4 times in comparison with those in the control, respectively. Under the saline stress, the activities
of superoxide dismutase (SOD) and catalase (CAT) were induced, but the contents of ascorbic acid (AA) and glutathione (GSH)
decreased, and MDA largely accumulated. The various pretreatments efficiently counteracted the salt-caused growth inhibition,
especially with H2O2 + CaCl2 the shoot and root dry weights reduced only 9.4% and 24.4% of the non salt-stressed plants. The determination of endogenous
H2O2 level demonstrated that the pretreatments induced H2O2 accumulation, with H2O2 + CaCl2 being most efficient, but the effect was transient. After 7 days of saline stress, the H2O2 contents in the pretreated shoots and roots accounted for 23.7–41.8% and 31.7–57.3% of the non-pretreated plants, varying
according to the different pretreatments. Under saline stress, SOD and CAT further increased, AA and GSH maintained higher
levels and MDA decreased in the pretreated plants compared to the untreated plants. With application of diphenylene iodonium
(DPI) during the pretreatment, which inhibited the accumulation of H2O2, the ameliorative effect of the pretreatment on salt-caused plant growth inhibition was reduced. However, applied DPI at
the immediate end of the pretreatment did not alter its favorable role, indicating a H2O2 peak formed at the early time of saline stress might play an important role in regulating plant tolerance to saline stress. 相似文献
20.
F. Nikravesh R. A. Khavari-Nejad H. Rahimian H. Fahimi 《Acta Physiologiae Plantarum》2012,34(2):419-427
Hairy root disease is caused by the infection of wounded higher plants with Agrobacterium rhizogenes. Transformation of tissues or plants with A. rhizogenes, and with rol genes, as well as hairy roots may produce alterations in the plant secondary metabolism. H2O2 and other ROS are involved as a signal in secondary metabolite production pathway and play a key role in plant defensive
reactions. In this work, the effect of A. rhizogenes T-DNA on nicotine content, antioxidant enzymes activity, H2O2 production, pattern of peroxidase (POX) and superoxide dismutase (SOD) isozymes in hairy roots and regenerated plants were
studied. Rise in SOD and POX activities in the transformed lines of TRa and TRb and in the resultant regenerated plants, also
the decreased level of H2O2 in them, compared with the untransformed lines indicates that, the T-DNA genes expression of A. rhizogenes probably decreases H2O2 level by increasing the production of antioxidant enzymes. Decrees the level of H2O2 content in TRc line in spite of the similarity of antioxidant enzyme activity in comparison with normal root, indicate that
A. rhizogenes activate other mechanisms except SOD and POX enzyme for reducing H2O2 level. 相似文献