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

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.

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

Acta Scientiarum Polonorum Hortorum Cultus ◽

10.24326/asphc.2019.2.4 ◽

2019 ◽

Vol 18 (2) ◽

pp. 29-37 ◽

Cited By ~ 1

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.

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

Frontiers in Plant Science ◽

10.3389/fpls.2021.789617 ◽

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.

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Physiological and Molecular Mechanisms of ABA and CaCl2 Regulating Chilling Tolerance of Cucumber Seedlings

Plants ◽

10.3390/plants10122746 ◽

2021 ◽

Vol 10 (12) ◽

pp. 2746

Author(s):

Qian Feng ◽

Sen Yang ◽

Yijia Wang ◽

Lu Lu ◽

Mintao Sun ◽

...

Keyword(s):

Low Temperature ◽

Combined Treatment ◽

Chilling Injury ◽

Control Treatment ◽

Water Control ◽

Cucumber Seedlings ◽

Injury Index ◽

Mda Content ◽

Cacl2 Treatment ◽

Relative Electrical Conductivity

Cold stress is a limiting factor to the growth and development of cucumber in the temperate regions; hence, improving the crop’s tolerance to low temperature is highly pertinent. The regulation of low-temperature tolerance with exogenous ABA and CaCl2 was investigated in the cucumber variety Zhongnong 26. Under low-temperature conditions (day/night 12/12 h at 5 °C), seedlings were sprayed with a single application of ABA, CaCl2, or a combination of both. Our analysis included a calculated chilling injury index, malondialdehyde (MDA) content, relative electrical conductivity, antioxidant enzyme activities (SOD, CAT, and APX), leaf tissue structure, and expression of cold-related genes by transcriptome sequencing. Compared with the water control treatment, the combined ABA + CaCl2 treatment significantly improved the superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) of the seedlings by 34.47%, 59.66%, and 118.80%, respectively (p < 0.05), and significantly reduced the chilling injury index, relative electrical conductivity, and MDA content, by 89.47%, 62.17%, and 44.55%, respectively (p < 0.05). Transcriptome analysis showed that compared with the water control treatment, 3442 genes were differentially expressed for the combined treatment, 3921 for the ABA treatment, and 1333 for the CaCl2 treatment. KEGG enrichment analysis for both the ABA and combined ABA + CaCl2 treatments (as compared to the water control) showed that it mainly involves genes of the photosynthesis pathway and metabolic pathways. Differentially expressed genes following the CaCl2 treatment were mainly involved in plant hormone signal transduction, plant–pathogen interaction, MAPK signaling pathway–plant, phenylpropanoid biosynthesis, and circadian rhythm–plant. qRT-PCR analysis and RNA-seq results showed a consistent trend in variation of differential gene expression. Overall, this study demonstrated that although all three treatments provided some protection, the combined treatment of ABA (35 mg/L) with CaCl2 (500 mg/L) afforded the best results. A combined ABA + CaCl2 treatment can effectively alleviate cold-stress damage to cucumber seedlings by inducing physiological changes in photosynthesis and metabolism, and provides a theoretical basis and technical support for the application of exogenous ABA and CaCl2 for low-temperature protection of cucumber seedlings.

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A new morphological method to identify cold tolerance of melon at seedling stage

Functional Plant Biology ◽

10.1071/fp19163 ◽

2020 ◽

Vol 47 (1) ◽

pp. 80

Author(s):

Meng Li ◽

Xiaoyu Duan ◽

Qian Wang ◽

Wei Chen ◽

Hongyan Qi

Keyword(s):

Cold Tolerance ◽

Chilling Stress ◽

Chilling Injury ◽

Accurate Method ◽

Seedling Stage ◽

Leaf Angle ◽

Injury Index ◽

Spad Value ◽

Yield And Quality ◽

Rate Maximum

Low temperature restrains the growth and development of melons, as well as severely impairing the yield and quality. To obtain a rapid and accurate method for evaluating cold tolerance of melon, 10 genotypes were selected to investigate their cold tolerance at seedling stage. Chilling stress (15°C/6°C, day/night) increased leaf angles and caused leaves wilted: the phenotypes of the 10 genotypes were obviously different. Thus, a new predicted method for chilling injury index (CII) of melon was constructed based on the change of leaf angle and leaf state. The CII showed significant correlation with survival rate, maximum photochemical quantum yield of PSII (Fv/Fm) and changes of SPAD value. Moreover, the validity of the method was further verified by seedlings growth, photosynthesis, membrane permeability and metabolites accumulation of four screened genotypes. Taken together, this work provides a morphological and accurate method for evaluating cold tolerance in melon.

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Oxidative Stress and Chilling Tolerance in Tomato Seedlings

HortScience ◽

10.21273/hortsci.31.4.645b ◽

1996 ◽

Vol 31 (4) ◽

pp. 645b-645

Author(s):

Kanogwan Kerdnaimongkol ◽

Anju Bhatia ◽

Robert J. Joly ◽

William R. Woodson

Keyword(s):

Oxidative Stress ◽

Hydrogen Peroxide ◽

Superoxide Dismutase ◽

Diurnal Variation ◽

Chilling Stress ◽

Chilling Injury ◽

Chilling Tolerance ◽

Light Period ◽

Tomato Seedlings ◽

Chilling Sensitivity

Diurnal variation in the chilling sensitivity of tomato seedlings was examined. Sensitivity to chilling in tomato seedlings is a response to light and not under the control of a circadian rhythm. Chilling sensitivity is highest in seedlings chilled at the end of the dark period, and these seedlings become more resistant to chilling injury upon exposure to the light. Diurnal variation in chilling sensitivity was associated with changes in catalase and superoxide dismutase activities. The results show an increase in catalase and superoxide dismutase activities at the end of the light period. The recovery of the net photosynthesis rate following chilling was faster in seedlings chilled at the end of the light period. It is suggested that an increase in catalase and superoxide dismutase activities at the end of light period before the chilling plays a role in the resistance to chilling stress in tomato seedlings. Forty-eight hours of 14°C acclimation or hydrogen peroxide pretreatment conferred chilling tolerance to tomato seedlings and were correlated with elevated catalase activity. Acclimated seedlings still exhibited diurnal variation in chilling sensitivity while hydrogen peroxide treated seedlings showed little evidence of a diurnal variation in chilling sensitivity. Transgenic tomato plants expressing an antisense catalase gene were generated. A several-fold decrease in total catalase has been detected in the leaf extracts of transformants. Preliminary analysis of these plants indicated that modification of reactive oxygen species scavenging in plant system can lead to change in oxidative stress tolerance.

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Exogenous Nitric Oxide Pretreatment Enhances Chilling Tolerance of Anthurium

Journal of the American Society for Horticultural Science ◽

10.21273/jashs04218-17 ◽

2018 ◽

Vol 143 (1) ◽

pp. 3-13 ◽

Cited By ~ 7

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.

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

HortScience ◽

10.21273/hortsci.31.4.580e ◽

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.

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Effects of Low Oxygen and High Carbon Dioxide Atmospheres on the Chilling Sensitivity of Cucumber Seedlings

HortScience ◽

10.21273/hortsci.32.3.539b ◽

1997 ◽

Vol 32 (3) ◽

pp. 539B-539

Author(s):

Mary E. Mangrich ◽

Mikal E. Saltveit

Keyword(s):

Carbon Dioxide ◽

Chilling Injury ◽

Chilling Tolerance ◽

Low Oxygen ◽

High Carbon ◽

Radicle Growth ◽

Cucumber Seedlings ◽

Carbon Dioxide Levels ◽

The Individual ◽

High Carbon Dioxide

Crops with origins in tropics and subtropics undergo physiological injury when subjected to nonfreezing temperatures below 12°C. Application of heat and chemical shocks to tissue prior to chilling induces chilling tolerance. This study was undertaken to investigate the effects of low oxygen and high carbon dioxide atmospheres on subsequent chilling tolerance. Cucumber seedlings (Cucumis sativus L., cv. Poinsett 76) with radicles 8 to 12 mm long were subjected to 0% to 21% oxygen and/or 0% to 20% CO2 atmospheres for 0 to 72 hr at 2.5 or 15°C. After chilling, they were placed at 25°C for three additional days. Radicle growth was used to assess chilling injury. Modification of the individual germination plates was necessary to ensure seedling exposure to the desired atmospheres. Chilling injury was reduced by exposure to oxygen levels below 1% and to carbon dioxide levels above 5%. Effects of brief exposures were small in comparison to prolonged exposures during chilling. Seed to seed variability was high and obscured some results. The effects of the various atmospheres were greater with the less vigorous seedlings.

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Seed treatment with glycine betaine enhances tolerance of cotton to chilling stress

The Journal of Agricultural Science ◽

10.1017/s0021859618000278 ◽

2018 ◽

Vol 156 (3) ◽

pp. 323-332 ◽

Cited By ~ 4

Author(s):

C. Cheng ◽

L. M. Pei ◽

T. T. Yin ◽

K. W. Zhang

Keyword(s):

Enzyme Activity ◽

Cell Membrane ◽

Glycine Betaine ◽

Chilling Stress ◽

Chilling Injury ◽

Chilling Tolerance ◽

Early Spring ◽

Seedling Stage ◽

Preliminary Treatment ◽

Cotton Production

AbstractChilling injury is an important natural stress that can threaten cotton production, especially at the sowing and seedling stages in early spring. It is therefore important for cotton production to improve chilling tolerance at these stages. The current work examines the potential for glycine betaine (GB) treatment of seeds to increase the chilling tolerance of cotton at the seedling stage. Germination under cold stress was increased significantly by GB treatment. Under low temperature, the leaves of seedlings from treated seeds exhibited a higher net photosynthetic rate (PN), higher antioxidant enzyme activity including superoxide dismutase, ascorbate peroxidase and catalase, lower hydrogen peroxide (H2O2) content and less damage to the cell membrane. Enzyme activity was correlated negatively with H2O2 content and degree of damage to the cell membrane but correlated positively with GB content. The experimental results suggested that although GB was only used to treat cotton seed, the beneficial effect caused by the preliminary treatment of GB could play a significant role during germination that persisted to at least the four-leaf seedling stage. Therefore, it is crucial that this method is employed in agricultural production to improve chilling resistance in the seedling stage by soaking the seeds in GB.

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Insights into Nitric Oxide-Mediated Water Balance, Antioxidant Defence and Mineral Homeostasis in Rice (Oryza sativa L.) under Chilling Stress

10.20944/preprints202001.0153.v1 ◽

2020 ◽

Author(s):

Abdullah Al Mamun Sohag ◽

Md Tahjib-Ul-Arif ◽

Sonya Afrin ◽

Md Kawsar Khan ◽

Md. Abdul Hannan ◽

...

Keyword(s):

Nitric Oxide ◽

Oryza Sativa ◽

Molecular Mechanisms ◽

Oryza Sativa L ◽

Chilling Stress ◽

Soluble Sugar ◽

Chilling Injury ◽

Chilling Tolerance ◽

No Donor ◽

Mineral Homeostasis

Being a chilling-sensitive staple crop, rice (Oryza sativa L.) is vulnerable to climate change. The competence of rice to withstand chilling stress should, therefore, be enhanced through technological tools. The present study employed chemical intervention like application of sodium nitroprusside (SNP) as nitric oxide (NO) donor and elucidated the underlying molecular mechanisms of NO-mediated chilling tolerance in rice. At germination stage, germination indicators were interrupted by chilling stress (5.0 ± 1.0°C for 8 h day‒1), while pretreatment with 100 μM SNP markedly improved the indicators. At seedling stage (14-day-old), chilling stress caused stunted growth with visible toxicity along with alteration of biochemical markers, for example, increase in oxidative stress markers (superoxide, hydrogen peroxide, and malondialdehyde) and osmolytes (total soluble sugar; proline and soluble protein content, SPC), and decrease in chlorophyll (Chl), relative water content (RWC), and antioxidants. However, NO application attenuated toxicity symptoms with improving growth performance which might be attributed to enhanced activities of antioxidants, mineral contents, Chl, RWC and SPC. Furthermore, principal component analysis indicated that water imbalance and increased oxidative damage were the main contributors to chilling injury, whereas NO-mediated mineral homeostasis and antioxidant defense were the critical determinants for chilling tolerance in rice. Collectively, our findings revealed that NO protects against chilling stress through valorizing cellular defense mechanisms, suggesting that exogenous application of NO could be a potential tool to evolve cold tolerance as well as climate resilience in rice.

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