scholarly journals Effects of Ethanol on Membrane Integrity and Enzyme Expression in Chilled Cucumber Seedlings

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 580e-580
Author(s):  
Windy Boyd ◽  
Paul H. Jennings
Keyword(s):  
Catalase Activity ◽  
Active Oxygen Species ◽  
Chilling Stress ◽  
Membrane Integrity ◽  
Radical Scavenging ◽  
Chilling Tolerance ◽  
Time Interval ◽  
Ethanol Treatment ◽  
Cucumber Seedlings ◽  
Membrane Effects

Previous experiments have shown that chilling-stressed cucumber seedlings treated with ethanol have greater chilling tolerance when compared to untreated seedlings. To determine whether this increased chilling tolerance would diminish with time after treatment, cucumber seedlings were treated with ethanol and placed at chilling temperatures for 0, 2, 4, 6, or 8 hours after ethanol treatment. Ethanol-induced chilling tolerance declined as the time interval between treatment and chilling exposure increased. A second ethanol treatment was given 3 hours after the first treatment in an attempt to extend the enhanced chilling tolerance response. Ethanol has been reported to function as an anesthetic in some systems, interacting with cellular membranes. To determine the effect of ethanol and chilling on membrane integrity, a malondialdehyde assay was used. Since chilling stress effects may result from accumulation of active oxygen species, the activity of one radical scavenging enzyme (catalase) has been assayed. Ethanol treatment resulted in a rapid increase in catalase activity, and was associated with increased chilling tolerance. The effect of a second ethanol treatment will be discussed as related to induced chilling tolerance, membrane effects, and catalase activity.

scholarly journals H2O2 Functions as a Downstream Signal of IAA to Mediate H2S-Induced Chilling Tolerance in Cucumber

2021 ◽  
Vol 22 (23) ◽  
pp. 12910
Author(s):  
Xiaowei Zhang ◽  
Yanyan Zhang ◽  
Chenxiao Xu ◽  
Kun Liu ◽  
Huangai Bi ◽  
...  
Keyword(s):  
Chilling Stress ◽  
Chilling Injury ◽  
Chilling Tolerance ◽  
H2o2 Production ◽  
Mrna Levels ◽  
Sodium Hydrosulfide ◽  
Polar Transport ◽  
Cucumber Seedlings ◽  
Injury Index ◽  
Transport Inhibitor

Hydrogen sulfide (H2S) plays a crucial role in regulating chilling tolerance. However, the role of hydrogen peroxide (H2O2) and auxin in H2S-induced signal transduction in the chilling stress response of plants was unclear. In this study, 1.0 mM exogenous H2O2 and 75 μM indole-3-acetic acid (IAA) significantly improved the chilling tolerance of cucumber seedlings, as demonstrated by the mild plant chilling injury symptoms, lower chilling injury index (CI), electrolyte leakage (EL), and malondialdehyde content (MDA) as well as higher levels of photosynthesis and cold-responsive genes under chilling stress. IAA-induced chilling tolerance was weakened by N, N′-dimethylthiourea (DMTU, a scavenger of H2O2), but the polar transport inhibitor of IAA (1-naphthylphthalamic acid, NPA) did not affect H2O2-induced mitigation of chilling stress. IAA significantly enhanced endogenous H2O2 synthesis, but H2O2 had minimal effects on endogenous IAA content in cucumber seedlings. In addition, the H2O2 scavenger DMTU, inhibitor of H2O2 synthesis (diphenyleneiodonium chloride, DPI), and IAA polar transport inhibitor NPA reduced H2S-induced chilling tolerance. Sodium hydrosulfide (NaHS) increased H2O2 and IAA levels, flavin monooxygenase (FMO) activity, and respiratory burst oxidase homolog (RBOH1) and FMO-like protein (YUCCA2) mRNA levels in cucumber seedlings. DMTU, DPI, and NPA diminished NaHS-induced H2O2 production, but DMTU and DPI did not affect IAA levels induced by NaHS during chilling stress. Taken together, the present data indicate that H2O2 as a downstream signal of IAA mediates H2S-induced chilling tolerance in cucumber seedlings.

scholarly journals Exogenous Nitric Oxide Pretreatment Enhances Chilling Tolerance of Anthurium

2018 ◽  
Vol 143 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Lijian Liang ◽  
Yanming Deng ◽  
Xiaobo Sun ◽  
Xinping Jia ◽  
Jiale Su
Keyword(s):  
Nitric Oxide ◽  
Fruits And Vegetables ◽  
Chilling Stress ◽  
Chilling Injury ◽  
Photochemical Efficiency ◽  
Membrane Integrity ◽  
Antioxidant Response ◽  
Chilling Tolerance ◽  
No Donor ◽  
Cell Membrane Integrity

Nitric oxide (NO) is well known for its multifaceted physiological roles as a signaling molecule in plants. Previous studies have indicated that exogenous application of NO may be useful for alleviating chilling injury (CI) in fruits and vegetables. However, the potential role and mechanism of NO in mitigating chilling stress in anthurium (Anthurium andraeanum) remain unclear. In this study, physiological and biochemical analysis were performed to investigate the effects of exogenous NO in alleviating CI in anthurium. Anthurium seedling plants were treated with the NO donor sodium nitroprusside (SNP) at four concentrations (0, 0.2, 0.4, and 0.8 mm) and stored at 12/5 °C (day/night) for 15 day. The results showed that exogenous SNP mitigated the adverse effects of chilling on anthurium, and the most effective concentration was 0.2 mm. In addition, NO effectively improved the CI index, malondialdehyde (MDA) content, electrolyte leakage, photochemical efficiency (Fv/Fm), and chlorophyll loss of anthurium during low temperatures. Pretreatment with SNP also increased the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX); the content of antioxidants including glutathione (GSH), ascorbic acid (AsA), and phenolics; and reduced the accumulation of hydrogen peroxide and O2−. SNP pretreatment at 0.2 mm also significantly promoted the accumulation of proline, increased the activity of Δ1-pyrroline-5-carboxylate synthetase (P5CS), and reduced the activity of proline dehydrogenase (PDH), when compared with control (0 mm SNP→Chilling) under chilling stress. These results indicated that NO could enhance the chilling tolerance of anthurium by elicitation of an antioxidant response and proline accumulation for maintaining cell membrane integrity.

scholarly journals Effects of Chilling and Ethanol Treatments on the Antioxidant Systems of Cucumber Seedling Roots

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 538F-539
Author(s):  
Windy A. Boyd ◽  
Paul H. Jennings
Keyword(s):  
Active Oxygen Species ◽  
Chilling Tolerance ◽  
Ethanol Solution ◽  
Antioxidant Systems ◽  
Control Group ◽  
Ethanol Treatment ◽  
Treatment Groups ◽  
Seedling Roots ◽  
Chilling Temperatures ◽  
Scavenging Enzymes

Previous experiments have shown that soaking 24-hr-old cucumber seedlings in ethanol leads to an increase in chilling tolerance. Seedlings were immersed in a 500-mM ethanol solution for 2 hr prior to chilling, rinsed, and placed in chilling immediately after treatment. All seedlings (except the control group) were treated for 2 hr after a 24-hr germination period at 25°C and a second group was held for 3 hr to allow the ethanol-induced chilling tolerance to dissipate. At this time, the seedlings were retreated with a second ethanol treatment identical to the first. The induction of chilling tolerance seen in both treatment groups was measured as an increase in root growth and decreases in lipid peroxidation and electrolyte leakage after exposure to chilling temperatures (2°C). Although ethanol treatment does clearly enhance chilling tolerance, the mechanisms by which it does so are unclear. Some hypotheses have suggested that ethanol acts as an anaesthetic, preventing a membrane phase change from a liquid to a gel-like state. Other evidence indicates that ethanol is a scavenger of the hydroxyl radical, working in concert with enzymatic-reducing systems and antioxidants to directly prevent damage caused by active oxygen species. Because enzymatic reducing systems and antioxidants have been shown to combat stress, the activities of three H2O2-scavenging enzymes (catalase, glutathione reductase, and ascorbate-specific peroxidase), along with the relative concentrations of reduced and oxidized forms of glutathione and ascorbate as affected by both chilling and ethanol treatments will be discussed in relation to chilling susceptibility.

scholarly journals HARDENING PRETREATMENT BY DROUGHT AND LOW TEMPERATURE ENHANCED CHILLING STRESS TOLERANCE OF CUCUMBER SEEDLINGS

2019 ◽  
Vol 18 (2) ◽  
pp. 29-37 ◽  
Author(s):  
Fardin Ghanbari ◽  
Sajad Kordi
Keyword(s):  
Low Temperature ◽  
Chilling Stress ◽  
Chilling Injury ◽  
Warm Season ◽  
Chilling Tolerance ◽  
Limiting Factors ◽  
Antioxidant Enzyme Activities ◽  
Cucumber Seedlings ◽  
Injury Index ◽  
Randomized Design

Chilling stress is of major limiting factors influencing the growth and development of warm-season crops like cucumber. In this research, the possibility of chilling tolerance of cucumber seedlings was investigated through employing the drought and low-temperature pretreatments. The factorial experiment consisted of two factors including cucumber cultivars (i.e. ‘Super Dominos’ and ‘Super Star’) and hardening treatments (control, low temperatures at 10°C, and 15°C and drought simulated by 10% and 20% PEG) based on completely randomized design (CRD) in 3 replications. After applying treatments and providing them 48 h opportunity to be recovered, the seedlings were subjected to 3°C for a six-day period and 6 h for each day. All hardening treatments improved seedlings’ growth, chlorophyll content, total phenol (TP) and antioxidant enzyme activities, while reducing chilling injury index and malondialdehyde (MDA) content. Comparing to temperature hardening, the drought pretreatment showed to have a better effect on inducing the chilling tolerance into cultivars. Overall, the results of this experiment showed that employing drought and low-temperature pretreatments enabled cucumber seedlings to mitigate the harmful effects of chilling.

scholarly journals Effects of Chilling, Ethanol, and Heat Shock on Enzyme Expression in Cucumber Seedling Roots

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 912D-912
Author(s):  
Windy A. Boyd ◽  
Paul H. Jennings
Keyword(s):  
Heat Shock ◽  
Catalase Activity ◽  
Chilling Tolerance ◽  
Activity Levels ◽  
Cucumber Seedling ◽  
Enzyme Expression ◽  
Cucumber Seedlings ◽  
Before And After ◽  
Seedling Roots ◽  
Chilling Period

Chilling-sensitive cucumber seedlings that are treated with ethanol or heat-shocked have shown an increase in chilling tolerance. The mechanisms that regulate this response have not been identified. Cucumber seeds were germinated for 24 h and then treated with 500 mM ethanol for 2 h or heat-shocked at 40C for 3 h. Immediately after treatment, roots were excised and catalase activity was assayed. Another set of control and treated seeds were chilled for 72 h and catalase was assayed at the end of the chilling period. Comparisons will be presented between catalase activity levels before and after chilling, as well as between the control and treated groups. Treatments of ethanol and heat shock resulted in an increase in catalase activity when compared to controls.

scholarly journals Melatonin Promotes the Chilling Tolerance of Cucumber Seedlings by Regulating Antioxidant System and Relieving Photoinhibition

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaowei Zhang ◽  
Yiqing Feng ◽  
Tongtong Jing ◽  
Xutao Liu ◽  
Xizhen Ai ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Large Subunit ◽  
Chilling Stress ◽  
Chilling Injury ◽  
Photochemical Efficiency ◽  
Photosynthetic Apparatus ◽  
Chilling Tolerance ◽  
Growth And Yield ◽  
Bisphosphate Carboxylase ◽  
Cucumber Seedlings

Chilling adversely affects the photosynthesis of thermophilic plants, which further leads to a decline in growth and yield. The role of melatonin (MT) in the stress response of plants has been investigated, while the mechanisms by which MT regulates the chilling tolerance of chilling-sensitive cucumber remain unclear. This study demonstrated that MT positively regulated the chilling tolerance of cucumber seedlings and that 1.0 μmol⋅L–1 was the optimum concentration, of which the chilling injury index, electrolyte leakage (EL), and malondialdehyde (MDA) were the lowest, while growth was the highest among all treatments. MT triggered the activity and expression of antioxidant enzymes, which in turn decreased hydrogen peroxide (H2O2) and superoxide anion (O2⋅–) accumulation caused by chilling stress. Meanwhile, MT attenuated the chilling-induced decrease, in the net photosynthetic rate (Pn) and promoted photoprotection for both photosystem II (PSII) and photosystem I (PSI), regarding the higher maximum quantum efficiency of PSII (Fv/Fm), actual photochemical efficiency (ΦPSII), the content of active P700 (ΔI/I0), and photosynthetic electron transport. The proteome analysis and western blot data revealed that MT upregulated the protein levels of PSI reaction center subunits (PsaD, PsaE, PsaF, PsaH, and PsaN), PSII-associated protein PsbA (D1), and ribulose-1,5-bisphosphate carboxylase or oxygenase large subunit (RBCL) and Rubisco activase (RCA). These results suggest that MT enhances the chilling tolerance of cucumber through the activation of antioxidant enzymes and the induction of key PSI-, PSII-related and carbon assimilation genes, which finally alleviates damage to the photosynthetic apparatus and decreases oxidative damage to cucumber seedlings under chilling stress.

scholarly journals Physiological and transcriptome changes induced by exogenous putrescine in anthurium under chilling stress

2020 ◽  
Vol 61 (1) ◽  
Author(s):  
Xiangli Sun ◽  
Zebin Yuan ◽  
Bo Wang ◽  
Liping Zheng ◽  
Jianzhong Tan ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Chilling Stress ◽  
Chilling Tolerance ◽  
Membrane Lipid ◽  
Control Group ◽  
Qrt Pcr ◽  
Differential Gene ◽  
Anthurium Andraeanum ◽  
Chilling Response

Abstract Background Chilling stress is the major factor limiting plant productivity and quality in most regions of the world. In the present study, we aimed to evaluate the effects of putrescine (Put) and polyamine inhibitor d-arginine (d-arg) on the chilling tolerance of anthurium (Anthurium andraeanum). Results Anthurium seedlings were pretreated with five different concentrations of Put solution or d-arg solution. Subsequently, the seedlings were subjected to chilling stress at 6 °C for 3 days, followed by a recovery at 25 °C for 1 day. Relative permeability of the plasma membrane, as well as physiological and morphologic parameters was assessed during the experiments. Additionally, transcriptome sequencing and patterns of differential gene expression related to chilling response were analyzed by qRT-PCR in 1.0 mM Put-treated and untreated anthurium seedlings. Results indicated that the supplementation of exogenous Put decreased the extent of membrane lipid peroxidation and the accumulation of malondialdehyde (MDA), promoted the antioxidant activities and proline content and maintained the morphologic performances compared with the control group. This finding indicated that the application of exogenous Put could effectively decrease the injury and maintain the quality of anthurium under chilling conditions. In contrast, the treatment of d-arg exhibited the opposite effects, which confirmed the effects of Put. Conclusions This research provided a possible approach to enhance the chilling tolerance of anthurium and reduce the energy consumption used in anthurium production.

CO2 laser enhances the chilling tolerance of wheat seedlings by stimulating NO synthesis

2016 ◽  
Vol 96 (5) ◽  
pp. 796-807
Author(s):  
Yi-ping Chen ◽  
Qiang Liu ◽  
Dong Chen
Keyword(s):  
Nitric Oxide ◽  
Laser Irradiation ◽  
Sodium Tungstate ◽  
Chilling Stress ◽  
Chilling Tolerance ◽  
The Other ◽  
Control Group ◽  
Wheat Seedlings ◽  
Oxide Synthase ◽  
Protein Treatment

To investigate the mechanism by which laser irradiation enhances the chilling tolerance of wheat seedlings, seeds were exposed to different treatments, and biochemical parameters were measured. Compared with the control group, chilling stress (CS) led to an increase in the concentrations of malondialdehyde (MDA) and H2O2, and decreases in the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), catalase (CAT), peroxidase (POD), and nitric oxide synthase (NOS), and the concentrations of nitric oxide (NO) and protein. Treatment with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), sodium tungstate (ST), and NG-nitro-L-arginine methyl ester (L-NAME) followed by CS resulted in further increases in the concentrations of MDA and H2O2 and further decreases in the other parameters. However, treatment with PTIO, ST, and L-NAME followed by laser irradiation had the opposite effects on these parameters. When the seeds were treated with PTIO, ST, and L-NAME followed by laser and CS, the concentrations of MDA and H2O2 were significantly lower and the other parameters were higher than in the PTIO, ST, and L-NAME plus CS groups. These results suggest that CO2 laser irradiation enhances the chilling tolerance of wheat seedlings by stimulating endogenous NO synthesis.

Sequestration and Oxygen Radical Detoxification as Mechanisms of Paraquat Resistance

Weed Science ◽  
1994 ◽  
Vol 42 (2) ◽  
pp. 277-284 ◽  
Author(s):  
Jonathan J. Hart ◽  
Joseph M. Di Tomaso
Keyword(s):  
Active Oxygen Species ◽  
Radical Scavenging ◽  
Resistance Mechanisms ◽  
Oxygen Radical ◽  
Membrane Properties ◽  
Chloroplast Envelope ◽  
Cross Resistance ◽  
Paraquat Resistance ◽  
Plant Cell Membranes ◽  
Scavenging Enzymes

Evidence in the literature has generally supported either of two paraquat resistance mechanisms: an increase in activity of oxygen radical-scavenging enzymes in resistant plants which affords protection from active oxygen species formed by paraquat; and sequestration of paraquat away from its site of action in the chloroplast. Evidence for the first model relies primarily on measurement of increased enzyme activity and cross-resistance to other oxygen radical-generating stresses in resistant plants. The sequestration model is supported by data showing decreased translocation of paraquat and absence of paraquat injury in plant systems that do not have increased levels of protective enzymes. An alteration in paraquat transport at one of several plant cell membranes could confer resistance by modifying movement of paraquat into the compartment bounded by that membrane. Properties of the plasmalemma, chloroplast envelope, and tonoplast that may be important to paraquat transport are discussed and data supporting or discounting specific membrane alterations in resistant plants are presented. Finally, the possibility that both mechanisms may work in concert is addressed.

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