scholarly journals Concomitant  accumulations of ions, osmoprotectants and antioxidant system-related  substances provide salt tolerance capability to succulent extreme-halophyte Scorzonera hieraciifolia             

2021 ◽  
Author(s):  
Cansu ALTUNTAŞ ◽  
Rabiye TERZİ
Keyword(s):  
Hydrogen Peroxide ◽  
Salt Tolerance ◽  
Antioxidant Enzyme ◽  
Antioxidant System ◽  
Enzyme Activities ◽  
Inorganic Ions ◽  
Antioxidant Enzyme Activities ◽  
Guaiacol Peroxidase ◽  
Tolerance Mechanism ◽  
Calcium Magnesium

Halophytes adapting to live in salinized areas can activate some tolerance mechanism through signal compounds to cope with salinity. However, the role of co-activity of signal compounds in salt tolerance of halophytes is not yet fully understood. We have firstly detected that Scorzonera hieraciifolia with fleshy shoots is a succulent extreme-halophyte and researched the changes in signal compounds involved in the salt tolerance mechanism, including inorganic ions, osmoprotectants and substances related to antioxidant system. The levels of signal compounds such as calcium, magnesium, proline, soluble sugar, hydrogen peroxide, superoxide, ascorbate and glutathione concomitantly increased when thickness of shoot tissues enhanced under excess salinity. There were 3.3-fold, 5-fold, 8-fold and 10-fold enhancements in the levels of inorganic ions (Ca and Mg), hydrogen peroxide, ascorbate and glutathione in the shoots treated with excess salinity, respectively. Contents of sodium, potassium and chlorine, and antioxidant enzyme activities, superoxide dismutase, guaiacol peroxidase, ascorbate peroxidase, catalase and glutathione reductase, also increased in the salinized shoots. Western blot analysis showed that the increases in antioxidant enzyme activities were consistent with increases in their protein contents. The results suggest that extraordinary salt tolerance capacity in Scorzonera hieraciifolia, a succulent extreme-halophyte can be improved by modulated accumulations of signal compounds, especially calcium, magnesium, osmoprotectants, reactive oxygen species and antioxidant substances. Moreover, massive induction of antioxidant enzymes can make strong contributions to salt stress tolerance of S. hieraciifolia.

scholarly journals Seed priming with hydrogen peroxide alleviates the effects of drought stress in rice (Oryza sativa L.) seedlings

2020 ◽  
Vol 48 (1) ◽  
pp. 273-283
Author(s):  
Weeraphorn JIRA-ANUNKUL ◽  
Wattana PATTANAGUL
Keyword(s):  
Hydrogen Peroxide ◽  
Oryza Sativa ◽  
Drought Stress ◽  
Antioxidant Enzyme ◽  
Enzyme Activities ◽  
Oryza Sativa L ◽  
Seed Priming ◽  
Rice Seedling ◽  
Antioxidant Enzyme Activities ◽  
Guaiacol Peroxidase

Drought stress is a major factor limiting crop growth and yield. Hydrogen peroxide (H2O2) is known as a signalling molecule in the plant cell in which activates multiple physiological changes that play essential roles in tolerance mechanism. This study investigated the effects of seed priming with H2O2 on growth, some physiological characteristics and antioxidant enzyme activities in rice seedling under drought stress. Rice (Oryza sativa L.) cv. Khao Dawk Mali 105 seeds were primed with 0 (distilled water), 1, 5, 10, and 15 mM H2O2 and grown for 21 days. The seedlings were subjected to drought stress by withholding water for 7 days. The results showed that priming with low concentrations of H2O2 improved plant growth and biomass as well as relative water content, malondialdehyde content, electrolyte leakage. Priming with H2O2, however, had no beneficial effect on chlorophyll content, proline and leaf total soluble sugar. Seed priming with appropriate levels of H2O2 also enhanced antioxidant enzyme activities including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (GPX). It is concluded that seed priming with 2-10 mM H2O2, is beneficial for enhancing drought tolerance in rice seedling by increasing antioxidant capacity, which in turn reduces oxidative stress and damages to the cellular components.

scholarly journals Physiological and Antioxidant Parameters in Two Lycoris Species as Influenced by Water Deficit Stress

HortScience ◽  
2015 ◽  
Vol 50 (11) ◽  
pp. 1702-1708 ◽  
Author(s):  
Sheng Xu ◽  
Mingmin Jiang ◽  
Jiangyan Fu ◽  
Lijian Liang ◽  
Bing Xia ◽  
...  
Keyword(s):  
Antioxidant Enzyme ◽  
Water Deficit ◽  
Enzyme Activities ◽  
Water Status ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Net Photosynthesis ◽  
Water Deficit Stress ◽  
Antioxidant Enzyme Activities ◽  
Guaiacol Peroxidase

From a field experiment, the changes in morphophysiological characters and antioxidant enzyme activities were studied in two Lycoris species (Lycoris radiata and Lycoris aurea) subjected to 16 days of water deficit stress. With the increase of water deficit stress processing time, leaf relative water content (RWC), membrane stability index (MSI), net photosynthesis (Pn), stomatal conductance (gS), transpiration rate (E), and chlorophyll (Chl) content decreased in both studied species. The water use efficiency (WUE) showed an opposite tendency between the two species under water deficit stress, where WUE of L. aurea decreased moderately and WUE of L. aurea increased somehow. Intercellular CO2 concentration (Ci) in L. aurea and L. radiata decreased in respond to water deficit stress at early stages of stress treatment, then increased throughout the rest of the stress period, and reached levels higher than those in well-watered plants at the end of the treatment. In addition, there was a significant increment in soluble sugar content and proline accumulation under water deficit stress in both species, and L. radiata showed a much more accumulation. The activity of superoxide dismutase (SOD), guaiacol peroxidase (POD), and ascorbate peroxidase (APX) increased in both plants subjected to water deficit stress while declined as the stress time increased. In L. aurea, catalase (CAT) showed a sustained increment, but it responded later and after a transient increase declined again in L. radiata under water deficit stress. In conclusion, L. radiata was more tolerant to water deficit stress than L. aurea as evidenced by its relatively higher water status, higher levels of proline, soluble sugar and pigments, and stronger photoprotection. Moreover, relatively higher antioxidant enzyme activities and lower levels of thiobarbituric acid reactive substances (TBARS) in L. radiata were also associated with its better protection against water deficit stress-induced oxidative damage.

scholarly journals Differences in Physiological Responses of Two Oat (Avena nuda L.) Lines to Sodic-Alkalinity in the Vegetative Stage

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1188
Author(s):  
Liyun Liu ◽  
Nateetorn Petchphankul ◽  
Akihiro Ueda ◽  
Hirofumi Saneoka
Keyword(s):  
Antioxidant Enzyme ◽  
Enzyme Activities ◽  
Physiological Responses ◽  
Antioxidant Enzyme Activities ◽  
Guaiacol Peroxidase ◽  
Alkaline Salt ◽  
Shoot Height ◽  
Transcript Levels ◽  
Avena Nuda ◽  
Alkalinity Tolerance

Sodic-alkalinity is a more seriously limiting factor in agricultural productivity than salinity. Oat (Avena nuda) is a salt-tolerant crop species and is therefore useful in studying the physiological responses of cereals to alkalinity. We evaluated the differential effects of sodic-alkalinity on two naked oat lines, Caoyou1 and Yanke1. Seedlings of the two lines were exposed to 50 mM alkaline salt mixture of NaHCO3 and Na2CO3 (18:1 molar ratio; pH 8.5) for 2 weeks in a soil environment. Sodic-alkalinity exposure led the assimilation of abundant Na+ at similar concentrations in the organs of both lines. However, Caoyou1 showed much stronger growth than Yanke1, exhibiting a higher dry weight, total leaf area, and shoot height under sodic-alkalinity. Further analysis showed that Caoyou1 was more sodic-alkalinity tolerance than Yanke1. This was firstly because of differences in the oxidative stress defense mechanisms in leaves of the two lines. Antioxidant enzyme activities were either slightly elevated (catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GP), glutathione reductase (GR)) or unaltered (superoxide dismutase (SOD)) in Caoyou1 leaves, but some enzyme (SOD, GPOX, GR) activities were significantly reduced in Yanke1. AnAPX1 transcript levels significantly increased in Caoyou1 under sodic-alkalinity conditions compared with Yanke1, indicating its better antioxidant capacity. Secondly, the related parameters of Mg2+ concentration, phosphoenolpyruvate carboxylase (PEPC) activity, and AnPEPC transcript levels in the leaves showed significantly higher values in Caoyou1 compared with Yanke1. This demonstrated the effective utilization by Caoyou1 of accumulated HCO3− in the irreversible reaction from phosphoenolpyruvate to oxaloacetate to produce inorganic phosphorus, which was elevated in Caoyou1 leaves under alkalinity stress. Overall, the results demonstrated that the greater sodic-alkalinity tolerance of Caoyou1 is the result of: (1) maintained antioxidant enzyme activities; and (2) a higher capacity for the phosphoenolpyruvate to oxaloacetate reactions, as shown by the higher PEPC activity, Mg2+ concentration, and total phosphorus concentration in its leaves, despite the lower soil pH.

Respiration, hydrogen peroxide levels and antioxidant enzyme activities during cold storage of zucchini squash fruit

2009 ◽  
Vol 52 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Stefano Gualanduzzi ◽  
Elena Baraldi ◽  
Ilaria Braschi ◽  
Francesco Carnevali ◽  
Carlo Emanuele Gessa ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Antioxidant Enzyme ◽  
Cold Storage ◽  
Enzyme Activities ◽  
Antioxidant Enzyme Activities

scholarly journals Antioxidant Enzyme Activities as Biomarkers of Cu and Pb Stress in Centella asiatica

Stresses ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 253-265
Author(s):  
Chee Kong Yap ◽  
Wen Siang Tan ◽  
Koe Wei Wong ◽  
Ghim Hock Ong ◽  
Wan Hee Cheng ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Antioxidant Enzyme ◽  
Enzyme Activities ◽  
Synergistic Effects ◽  
Centella Asiatica ◽  
Antioxidant Enzyme Activities ◽  
Guaiacol Peroxidase ◽  
Oxygen Species ◽  
Pb Stress

The present study investigated the antioxidant enzyme activities (AEA) of ascorbate peroxidase (APX), catalase (CAT), guaiacol peroxidase (GPX), and superoxide dismutase (SOD) as biomarkers of Cu and Pb stress by using Centella asiatica grown in an experimental hydroponic condition. The results showed (i) higher accumulations of Cu and Pb in the roots of C. asiatica than those in the leaves, (ii) synergistic effects of Cu and Pb stress at higher metal-level exposures, and (iii) Cu and Pb stress triggered the increment of APX, CAT, GPX, and SOD levels in both the leaves and roots of C. asiatica. The increment of four AEA indicated that C. asiatica underwent oxidative stress caused by the production of reactive oxygen species when the plant was exposed to Cu and Pb. In order to prevent damages caused by Cu and Pb stress, the AEA system was heightened in C. asiatica, in which APX, CAT, GPX, and SOD can be used as biomarkers of Pb and Cu stress in the plant.

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