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

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.

Download Full-text

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

International Journal of Molecular Sciences ◽

10.3390/ijms222312910 ◽

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.

Download Full-text

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.

Download Full-text

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.

Download Full-text

In vitro selection of microspores for resistance to oxidative stress resulted in chilling tolerance in doubled haploid maize lines

Acta Agronomica Hungarica ◽

10.1556/aagr.59.2011.3.3 ◽

2011 ◽

Vol 59 (3) ◽

pp. 209-216

Author(s):

Eva Darkó ◽

H. Ambrus ◽

A. Szenzenstein ◽

B. Barnabás

Keyword(s):

Oxidative Stress ◽

Electron Transport ◽

Antioxidant Capacity ◽

Doubled Haploid ◽

Chilling Stress ◽

Photosynthetic Apparatus ◽

Photosynthetic Electron Transport ◽

Chilling Tolerance ◽

Chlorophyll Breakdown ◽

Induced Changes

The chilling tolerance of doubled haploid (DH) maize plants selected and regenerated from microspores exposed to prooxidants, paraquat or tert-butyl hydroperoxide was determined by monitoring cold-induced changes in the photosynthetic electron transport, CO2 assimilation processes and chlorophyll breakdown in young leaves after cold treatment (8°C for 5 days). The results were compared to those of the non-selected DH line and the original hybrid plants. Chilling stress caused a great reduction in the Fv/Fm, qP and ΔF/Fm’ fluorescence parameters, related to the photosynthetic electron transport processes, and in carbon assimilation, and resulted in chlorophyll breakdown. These changes were less extensive in the selected DH plants, which showed elevated antioxidant capacity both at ambient and at low temperature. Among the antioxidant enzymes tested, the activity of GR and GST was induced by chilling stress to the greatest extent. Correlations between cold-induced changes in the photosynthetic apparatus and the antioxidant capacity of the plants suggested that the better protection against oxidative stress induced by the elevated antioxidant capacity of the plants contributed to protecting the photosynthetic apparatus from cold.

Download Full-text

Salicylic Acid Is Involved in Rootstock–Scion Communication in Improving the Chilling Tolerance of Grafted Cucumber

Frontiers in Plant Science ◽

10.3389/fpls.2021.693344 ◽

2021 ◽

Vol 12 ◽

Author(s):

Xin Fu ◽

Yi-Qing Feng ◽

Xiao-Wei Zhang ◽

Yan-Yan Zhang ◽

Huan-Gai Bi ◽

...

Keyword(s):

Salicylic Acid ◽

Root Zone ◽

Chilling Stress ◽

Photochemical Efficiency ◽

Chilling Tolerance ◽

Rubisco Activase ◽

Protein Levels ◽

Binding Factor ◽

Cold Tolerant ◽

Cold Sensitive

Salicylic acid (SA) has been proven to be a multifunctional signaling molecule that participates in the response of plants to abiotic stresses. In this study, we used cold-sensitive cucumber and cold-tolerant pumpkin as experimental materials to examine the roles of SA in root–shoot communication responses to aerial or/and root-zone chilling stress in own-root and hetero-root grafted cucumber and pumpkin plants. The results showed that pumpkin (Cm) rootstock enhanced the chilling tolerance of grafted cucumber, as evidenced by the observed lower levels of electrolyte leakage (EL), malondialdehyde (MDA), and higher photosynthetic rate (Pn) and gene expression of Rubisco activase (RCA). However, cucumber (Cs) rootstock decreased the chilling tolerance of grafted pumpkins. Cs/Cm plants showed an increase in the mRNA expression of C-repeat-binding factor (CBF1), an inducer of CBF expression (ICE1), and cold-responsive (COR47) genes and CBF1 protein levels in leaves under 5/25 and 5/5°C stresses, or in roots under 25/5 and 5/5°C stresses, respectively, compared with the Cs/Cs. Chilling stress increased the endogenous SA content and the activity of phenylalanine ammonia-lyase (PAL), and the increase in SA content and activity of PAL in Cs/Cm plants was much higher than in Cs/Cs plants. Transcription profiling analysis revealed the key genes of SA biosynthesis, PAL, ICS, and SABP2 were upregulated, while SAMT, the key gene of SA degradation, was downregulated in Cs/Cm leaves, compared with Cs/Cs leaves under chilling stress. The accumulation of SA in the Cs/Cm leaves was mainly attributed to an increase in SA biosynthesis in leaves and that in transport from roots under aerial and root-zone chilling stress, respectively. In addition, exogenous SA significantly upregulated the expression level of cold-responsive (COR) genes, enhanced actual photochemical efficiency (ΦPSII), maximum photochemical efficiency (Fv/Fm), and Pn, while decreased EL, MDA, and CI in grafted cucumber. These results suggest that SA is involved in rootstock–scion communication and grafting-induced chilling tolerance by upregulating the expression of COR genes in cucumber plants under chilling stress.

Download Full-text

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.

Download Full-text

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.

Download Full-text

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.

Download Full-text

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.

Download Full-text

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.

Download Full-text