Ion Content, Antioxidant Enzyme Activity and Transcriptional Response Under Salt Stress and Recovery Condition in the Halophyte Grass Aeluropus Littoralis

Abstract Background: The production of reactive oxygen species (ROS) is a common feature of various plant cells in dealing with abiotic stresses. Plants have developed an effective enzymatic and non-enzymatic antioxidant defense systems to scavenge ROS and cope with oxidative stress. Halophyte antioxidant defense mechanisms represent one of the best examples for this trait. Several of salt-responsive promoters and genes originated here during evolution. The present work aimed to investigate a set of physiological, elemental, biochemical and molecular responses involved in tolerance to salt stress in the halophyte grass Aeluropus littoralis. Results: The content of total Chlorophyll (Chl), Chl a and Cars were increased under salinity condition, while the Chl b content was reduced. Sodium ion (Na+) in three time-points of salinity condition (S1, S2 and S3) significantly increased, and reduction was observed in three time-points of recovery condition (R1, R2 and R3). The amount of potassium ions (K+) in leaf and stem was decreased during salt stress, and increased during recovery condition. K+ accumulations in root significantly increased in S2 and S3. Calcium (Ca2+) and magnesium (Mg2+) content significantly declined in leaf, root and stem during stress treatment, whereas it increased significantly during recovery condition in the leaves. The amount of the amino acid proline, associated with drought and salt stress, as well as the activity of ROS related enzyme showed an increase during salt treatment. The APX, POD and SOD maximum activities were reported at S3 in roots while decreased at R. RT-qPCR analysis of antioxidant related genes showed up-regulation at S1 and S3 in root, but the down-regulation was observed in R. The highest transcription levels were observed in CAT and pAPX at S1 in leaf, while the maximum levels were seen in SOD and cAPX at S2.Conclusions: The halophyte mechanisms in A. littoralis, contribute to overcome ROS in oxidative stress. SOD activity was more responsive in S, indicating the importance of SOD in oxidative damage. Increasing proline content may be considered as a stress-induced marker to identify oxidative damage. During the salt stress phase an increase of mRNA abundance from genes encoding enzymes assiciated with atioxidant activities was found. The positive correlation between the transcript level of CAT and CAT activities in leaf indicated the important regulatory function during salt stress for detoxifying ROS. Based on the transcript abundance and activity CAT is proposed as the main H2O2-scavenging enzyme to keep the balance of redox reaction in A. littoralis. The salt stress tolerance is associated with high Na+ absorbtion for osmotic balance and a corresponding reduction in K+, Mg2+, and Ca2+ ions. Further it was found that plants under S3 and R2 had more chlorophyll b content as compared to chlorophyll a that demonstrated optimization of leaf function under high salt condition.

Download Full-text

Mitoubiquinol Mesylate Attenuated Diethyl Nitrosamine–Induced Hepatocellular Carcinoma Through Modulation of Mitochondrial Antioxidant Defense Systems

JCO Global Oncology ◽

10.1200/go.20.20000 ◽

2020 ◽

Vol 6 (Supplement_1) ◽

pp. 9-9

Author(s):

Adisa Rahmat Adetutu ◽

Sulaimon Lateef Adegboyega ◽

Okeke Ebele Geraldine ◽

Ariyo OC ◽

Abdulkareem Fatimah Biade

Keyword(s):

Oxidative Stress ◽

Hepatocellular Carcinoma ◽

Liver Function ◽

Oxidative Damage ◽

Wistar Rats ◽

Antioxidant Defense ◽

Tumor Incidence ◽

Defense Systems ◽

Significant Difference ◽

Antioxidant Defense Systems

PURPOSE Hepatocellular carcinoma (HCC) is a highly malignant cancer, with a high recurrence rate and a poor prognosis. Diethyl nitrosamine (DEN) cirrhosis HCC–induced model has revealed an association of cancer progression with oxidative stress and mitochondrial dysfunction. This study investigated the effects of mitoubiquinol mesylate (MitoQ), a mitochondrial targeted antioxidant derivative from ubiquinone on DEN-induced oxidative damage in HCC Wistar rats. METHODS Fifty male Wistar rats were randomly divided into 5 groups, 10 rats per group. Groups A, B, and C received distilled water 10 mL/kg DEN, and MitoQ orally for 16 weeks, respectively. Animals in group D were pretreated with MitoQ for 1 week followed by coadministration of MitoQ and DEN (protective effect), whereas group E received DEN for 8 weeks, then coadministration of DEN and MitoQ (therapeutic effect) until the end of the study. Survival index, tumor incidence, liver function indices, hematologic profile, mitochondrial respiratory enzymes, and antioxidant defense status were assessed. RESULTS Data obtained show that rats in groups D and E had 80% survival and decreased tumor incidence (40% and 60%, respectively) compared with group B. Similarly, MitoQ significantly ( P < .05) decreased the activities of liver function enzymes, while hemoglobin concentration, red blood cell count, and lymphocytes levels were significantly elevated compared with the DEN-only group. Furthermore, MitoQ significantly ( P < .05) protected the liver from DEN-induced oxidative damage; however, there was no significant difference ( P > .05) between activities of mitochondrial F1F0-ATPase and succinate dehydrogenase of groups A, B, D, and E, respectively, although these enzyme activities were significantly ( P < .05) elevated in group C. Macroscopic and microscopic features indicated a reversal of DEN-induced cellular degeneration in hepatocytes. CONCLUSION These data suggest that MitoQ treatment for 16 weeks attenuated DEN-induced oxidative stress indices via modulation of mitochondrial antioxidant defense systems and could alleviate the burden of HCC as a chemotherapeutic agent.

Download Full-text

Regulation of Reactive Oxygen Species and Antioxidant Defense in Plants under Salinity

International Journal of Molecular Sciences ◽

10.3390/ijms22179326 ◽

2021 ◽

Vol 22 (17) ◽

pp. 9326

Author(s):

Mirza Hasanuzzaman ◽

Md. Rakib Hossain Raihan ◽

Abdul Awal Chowdhury Masud ◽

Khussboo Rahman ◽

Farzana Nowroz ◽

...

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Salt Stress ◽

Oxidative Damage ◽

Antioxidant Defense ◽

Reactive Oxygen ◽

Antioxidant Defense System ◽

Ros Generation ◽

Oxygen Species ◽

Defense System

The generation of oxygen radicals and their derivatives, known as reactive oxygen species, (ROS) is a part of the signaling process in higher plants at lower concentrations, but at higher concentrations, those ROS cause oxidative stress. Salinity-induced osmotic stress and ionic stress trigger the overproduction of ROS and, ultimately, result in oxidative damage to cell organelles and membrane components, and at severe levels, they cause cell and plant death. The antioxidant defense system protects the plant from salt-induced oxidative damage by detoxifying the ROS and also by maintaining the balance of ROS generation under salt stress. Different plant hormones and genes are also associated with the signaling and antioxidant defense system to protect plants when they are exposed to salt stress. Salt-induced ROS overgeneration is one of the major reasons for hampering the morpho-physiological and biochemical activities of plants which can be largely restored through enhancing the antioxidant defense system that detoxifies ROS. In this review, we discuss the salt-induced generation of ROS, oxidative stress and antioxidant defense of plants under salinity.

Download Full-text

Are insulin-resistance and oxidative stress cause or consequence of aging

Experimental Biology and Medicine ◽

10.1177/1535370220929621 ◽

2020 ◽

Vol 245 (14) ◽

pp. 1260-1267

Author(s):

Sylwia Dzięgielewska-Gęsiak ◽

Dorota Stołtny ◽

Alicja Brożek ◽

Małgorzata Muc-Wierzgoń ◽

Ewa Wysocka

Keyword(s):

Oxidative Stress ◽

Insulin Resistance ◽

Antioxidant Status ◽

Antioxidant Defense ◽

Total Antioxidant Status ◽

Thiobarbituric Acid ◽

Elderly Individuals ◽

Total Antioxidant ◽

Antioxidant Defense Systems ◽

Antioxidant Markers

Insulin resistance (IR) may be associated with oxidative stress and leads to cardiovascular disorders. Current research focuses on interplay between insulin-resistance indices and oxidant-antioxidant markers in elderly individuals with or without insulin-resistance. The assessment involved anthropometric data (weight, height, BMI, percentage of body fat (FAT)) and biochemical tests (glucose, lipids, serum insulin and plasma oxidant-antioxidant markers: Thiobarbituric Acid-Reacting Substances (TBARS), Cu,Zn-superoxide dismutase (SOD-1) and total antioxidant status). Insulin resistance index (IR) assuming a cut-off point of 0.3 allows to divides groups into: insulin sensitive group (InsS) IR < 0,3 ( n = 35, median age 69.0 years) and insulin-resistant group (InsR) IR ≥ 0.3 ( n = 51, median age 71.0 years). Lipids and antioxidant defense system markers did not differentiate the investigated groups. In the InsR elderly group, the FAT was increased ( P < 0.000003) and TBARS ( P = 0.008) concentration decreased in comparison with InsS group. A positive correlation for SOD-1 and total antioxidant status ( P < 0.05; r = 0.434) and a negative correlation for TBARS and age ( P < 0.05 with r = −0.421) were calculated in InsR individuals. In elderly individuals, oxidative stress persists irrespective of insulin-resistance status. We suggest that increased oxidative stress may be consequence of old age. An insulin action identifies those at high risk for atherosclerosis, via congruent associations with oxidative stress and extra- and intra-cellular antioxidant defense systems. Thus, we maintain that insulin-resistance is not the cause of aging. Impact statement Insulin resistance is associated with oxidative stress leading to cardiovascular diseases. However, little research has been performed examining elderly individuals with or without insulin-resistance. We demonstrate that antioxidant defense systems alone is not able to abrogate insulin action in elderly individuals at high risk for atherosclerosis, whereas the combined oxidant-antioxidant markers (thiobarbituric acid-reacting substances (TBARS), Cu,Zn-superoxide dismutase (SOD-1), and total antioxidant status (TAS)) might be more efficient and perhaps produce better clinical outcome. In fact, a decrease in oxidative stress and strong interaction between antioxidant defense can be seen only among insulin-resistant elderly individuals. This is, in our opinion, valuable information for clinicians, since insulin-resistance is considered strong cardiovascular risk factor.

Download Full-text

Supplemental Selenium and Boron Mitigate Salt-Induced Oxidative Damages in Glycine max L.

Plants ◽

10.3390/plants10102224 ◽

2021 ◽

Vol 10 (10) ◽

pp. 2224

Author(s):

Mira Rahman ◽

Khussboo Rahman ◽

Khadeja Sultana Sathi ◽

Md. Mahabub Alam ◽

Kamrun Nahar ◽

...

Keyword(s):

Oxidative Stress ◽

Salt Stress ◽

Antioxidant Defense ◽

Foliar Application ◽

Growth Parameters ◽

Monodehydroascorbate Reductase ◽

Ros Scavenging ◽

H2o2 Content ◽

Mda Content ◽

Different Levels

The present investigation was executed with an aim to evaluate the role of exogenous selenium (Se) and boron (B) in mitigating different levels of salt stress by enhancing the reactive oxygen species (ROS) scavenging, antioxidant defense and glyoxalase systems in soybean. Plants were treated with 0, 150, 300 and 450 mM NaCl at 20 days after sowing (DAS). Foliar application of Se (50 µM Na2SeO4) and B (1 mM H3BO3) was accomplished individually and in combined (Se+B) at three-day intervals, at 16, 20, 24 and 28 DAS under non-saline and saline conditions. Salt stress adversely affected the growth parameters. In salt-treated plants, proline content and oxidative stress indicators such as malondialdehyde (MDA) content and hydrogen peroxide (H2O2) content were increased with the increment of salt concentration but the relative water content decreased. Due to salt stress catalase (CAT), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glyoxalase I (Gly I) and glyoxalase II (Gly II) activity decreased. However, the activity of ascorbate peroxidase (APX), glutathione reductase (GR), glutathione peroxidase (GPX), glutathione S-transferase (GST) and peroxidase (POD) increased under salt stress. On the contrary, supplementation of Se, B and Se+B enhanced the activities of APX, MDHAR, DHAR, GR, CAT, GPX, GST, POD, Gly I and Gly II which consequently diminished the H2O2 content and MDA content under salt stress, and also improved the growth parameters. The results reflected that exogenous Se, B and Se+B enhanced the enzymatic activity of the antioxidant defense system as well as the glyoxalase systems under different levels of salt stress, ultimately alleviated the salt-induced oxidative stress, among them Se+B was more effective than a single treatment.

Download Full-text

Exogenous Tebuconazole and Trifloxystrobin Regulates Reactive Oxygen Species Metabolism Toward Mitigating Salt-Induced Damages in Cucumber Seedling

Plants ◽

10.3390/plants8100428 ◽

2019 ◽

Vol 8 (10) ◽

pp. 428 ◽

Cited By ~ 5

Author(s):

Sayed Mohsin ◽

Mirza Hasanuzzaman ◽

M. Bhuyan ◽

Khursheda Parvin ◽

Masayuki Fujita

Keyword(s):

Reactive Oxygen Species ◽

Salt Stress ◽

Antioxidant Defense ◽

Ion Homeostasis ◽

Reactive Oxygen ◽

Cucumber Plant ◽

Enzymatic Antioxidants ◽

Oxygen Species ◽

Exogenous Application ◽

Antioxidant Defense Systems

The present study investigated the role of tebuconazole (TEB) and trifloxystrobin (TRI) on cucumber plants (Cucumis sativus L. cv. Tokiwa) under salt stress (60 mM NaCl). The cucumber plants were grown semi-hydroponically in a glasshouse. Plants were exposed to two different doses of fungicides (1.375 µM TEB + 0.5 µM TRI and 2.75 µM TEB + 1.0 µM TRI) solely and in combination with NaCl (60 mM) for six days. The application of salt phenotypically deteriorated the cucumber plant growth that caused yellowing of the whole plant and significantly destructed the contents of chlorophyll and carotenoids. The oxidative damage was created under salinity by increasing the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolytic leakage (EL) resulting in the disruption of the antioxidant defense system. Furthermore, in the leaves, stems, and roots of cucumber plants increased Na+ content was observed under salt stress, whereas the K+/Na+ ratio and contents of K+, Ca2+, and Mg2+ decreased. In contrast, the exogenous application of TEB and TRI reduced the contents of MDA, H2O2, and EL by improving the activities of enzymatic and non-enzymatic antioxidants. In addition, ion homeostasis was regulated by reducing Na+ uptake and enhanced K+ accumulation and the K+/Na+ ratio after application of TEB and TRI. Therefore, this study indicates that the exogenous application of TEB and TRI enhanced salt tolerance in cucumber plants by regulating reactive oxygen species production and antioxidant defense systems.

Download Full-text

The Role of Oxidative Stress in Cardiac Disease: From Physiological Response to Injury Factor

Oxidative Medicine and Cellular Longevity ◽

10.1155/2020/5732956 ◽

2020 ◽

Vol 2020 ◽

pp. 1-29 ◽

Cited By ~ 8

Author(s):

Rossella D’Oria ◽

Rossella Schipani ◽

Anna Leonardini ◽

Annalisa Natalicchio ◽

Sebastio Perrini ◽

...

Keyword(s):

Oxidative Stress ◽

Myocardial Injury ◽

Antioxidant Defense ◽

Experimental Studies ◽

Chemical Species ◽

Oxygen Species ◽

Molecular Abnormalities ◽

Defense Systems ◽

Antioxidant Defense Systems

Reactive oxygen species (ROS) are highly reactive chemical species containing oxygen, controlled by both enzymatic and nonenzymatic antioxidant defense systems. In the heart, ROS play an important role in cell homeostasis, by modulating cell proliferation, differentiation, and excitation-contraction coupling. Oxidative stress occurs when ROS production exceeds the buffering capacity of the antioxidant defense systems, leading to cellular and molecular abnormalities, ultimately resulting in cardiac dysfunction. In this review, we will discuss the physiological sources of ROS in the heart, the mechanisms of oxidative stress-related myocardial injury, and the implications of experimental studies and clinical trials with antioxidant therapies in cardiovascular diseases.

Download Full-text

Seed Treatment with Trichoderma longibrachiatum T6 Promotes Wheat Seedling Growth under NaCl Stress Through Activating the Enzymatic and Nonenzymatic Antioxidant Defense Systems

International Journal of Molecular Sciences ◽

10.3390/ijms20153729 ◽

2019 ◽

Vol 20 (15) ◽

pp. 3729 ◽

Cited By ~ 1

Author(s):

Shuwu Zhang ◽

Bingliang Xu ◽

Yantai Gan

Keyword(s):

Salt Stress ◽

Antioxidant Defense ◽

Wheat Seedling ◽

Nacl Stress ◽

Ros Scavenging ◽

Wheat Seedlings ◽

Defense Systems ◽

Antioxidant Defense Systems ◽

Scavenging Enzymes ◽

Different Levels

Salt stress is one of the major abiotic stresses limiting crop growth and productivity worldwide. Species of Trichoderma are widely recognized for their bio-control abilities, but little information is regarding to the ability and mechanisms of their promoting plant growth and enhancing plant tolerance to different levels of salt stress. Hence, we determined (i) the role of Trichoderma longibrachiatum T6 (TL-6) in promoting wheat (Triticum aestivum L.) seed germination and seedling growth under different levels of salt stress, and (ii) the mechanisms responsible for the enhanced tolerance of wheat to salt stress by TL-6. Wheat seeds treated with or without TL-6 were grown under different levels of salt stress in controlled environmental conditions. As such, the TL-6 treatments promoted seed germination and increased the shoot and root weights of wheat seedlings under both non-stress and salt-stress conditions. Wheat seedlings with TL-6 treatments under different levels of NaCl stress increased proline content by an average of 11%, ascorbate 15%, and glutathione 28%; and decreased the contents of malondialdehyde (MDA) by an average of 19% and hydrogen peroxide (H2O2) 13%. The TL-6 treatments induced the transcriptional level of reactive oxygen species (ROS) scavenging enzymes, leading to the increases of glutathione s-transferase (GST) by an average of 17%, glutathione peroxidase (GPX) 16%, ascorbate peroxidase (APX) 17%, glutathione reductase (GR) 18%, dehydroascorbate reductase (DHAR) 5%. Our results indicate that the beneficial strain of TL-6 effectively scavenged ROS under NaCl stress through modulating the activity of ROS scavenging enzymes, regulating the transcriptional levels of ROS scavenging enzyme gene expression, and enhancing the nonenzymatic antioxidants in wheat seedling in response to salt stress. Our present study provides a new insight into the mechanisms of TL-6 can activate the enzymatic and nonenzymatic antioxidant defense systems and enhance wheat seedling tolerance to different levels of salt stress at physiological, biochemical and molecular levels.

Download Full-text

High Protein Diet Induces Oxidative Stress in Rat Cerebral Cortex and Hypothalamus

International Journal of Molecular Sciences ◽

10.3390/ijms20071547 ◽

2019 ◽

Vol 20 (7) ◽

pp. 1547 ◽

Cited By ~ 6

Author(s):

Ewa Żebrowska ◽

Mateusz Maciejczyk ◽

Małgorzata Żendzian-Piotrowska ◽

Anna Zalewska ◽

Adrian Chabowski

Keyword(s):

Oxidative Stress ◽

Cerebral Cortex ◽

Oxidative Damage ◽

Antioxidant Defense ◽

High Protein Diet ◽

Brain Structures ◽

High Protein ◽

Protein Diet ◽

Standard Diet ◽

The Impact

This is the first study to analyze the impact of high protein diet (HPD) on antioxidant defense, redox status, as well as oxidative damage on both a local and systemic level. Male Wistar rats were divided into two equal groups (n = 9): HPD (44% protein) and standard diet (CON; 24.2% protein). After eight weeks, glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT), superoxide dismutase-1 (SOD-1), reduced glutathione (GSH), uric acid (UA), total antioxidant (TAC)/oxidant status (TOS) as well as advanced glycation end products (AGE), 4-hydroxynonenal (4-HNE), and malondialdehyde (MDA) were analyzed in the serum/plasma, cerebral cortex, and hypothalamus of HPD and CON rats. HPD resulted in higher UA concentration and activity of GPx and CAT in the hypothalamus, whereas in the cerebral cortex these parameters remained unchanged. A significantly lower GSH content was demonstrated in the plasma and hypothalamus of HPD rats when compared to CON rats. Both brain structures expressed higher content of 4-HNE and MDA, whereas AGE was increased only in the hypothalamus of HPD animals. Despite the enhancement in antioxidant defense in the hypothalamus, this mechanism does not protect the hypothalamus from oxidative damage in rats. Hypothalamus is more susceptible to oxidative stress caused by HPD.

Download Full-text

Pineal Proteins Upregulate Specific Antioxidant Defense Systems in the Brain

Oxidative Medicine and Cellular Longevity ◽

10.4161/oxim.2.2.8361 ◽

2009 ◽

Vol 2 (2) ◽

pp. 88-92 ◽

Cited By ~ 20

Author(s):

Vijay K. Bharti ◽

R. S. Srivastava

Keyword(s):

Oxidative Stress ◽

Pineal Gland ◽

Antioxidant Defense ◽

Bubalus Bubalis ◽

Female Rats ◽

Antioxidant Systems ◽

Secretory Product ◽

Defense Systems ◽

Antioxidant Defense Systems ◽

The Brain

The neuroendocrine functions of the pineal affect a wide variety of glandular and nervous system processes. Beside melatonin (MEL), the pineal gland secretes and expresses certain proteins essential for various physiological functions. It has been suggested that the pineal gland may also have an antioxidant role due to secretory product other than MEL. Therefore, the present study was designed to study the effect of buffalo (Bubalus bubalis) pineal proteins (PP) on the antioxidant defense system in the brain of female rats. The twenty-four rats were taken in present study and were divided into four groups: control (0 day), control (28 day), vehicle control and buffalo PP. The PP was injected 100 µg/kg BW intraperitoneal (i.p.) daily for 28 days. The activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione reductase (GR) and reduced glutathione (GSH) concentration and the levels of lipid peroxidation (LPO) in the brain tissue were measured to assess the antioxidant systems. These enzymes protect from adverse effects of free radicals and help in amelioration of oxidative stress. Buffalo pineal proteins administration did not cause any effect on brain LPO, whereas GPx, GR and GSH were significantly (p < 0.05) decreased. However, SOD and CAT activities were increased to significant levels than the control in PP treated rats. Our study herein suggested that buffalo (Bubalus bubalis) pineal proteins upregulates specific antioxidant defense systems and can be useful in control of various oxidative stress-induced neuronal diseases.

Download Full-text

Salt stress tolerance in cowpea is poorly related to the ability to cope with oxidative stress

Acta Botanica Croatica ◽

10.2478/botcro-2013-0010 ◽

2014 ◽

Vol 73 (1) ◽

pp. 78-89 ◽

Cited By ~ 2

Author(s):

Sidney C. Praxedes ◽

Fábio M. Damatta ◽

Claudivan F. De Lacerda ◽

José T. Prisco ◽

Enéas Gomes-Filho

Keyword(s):

Oxidative Stress ◽

Salt Stress ◽

Oxidative Damage ◽

Stress Tolerance ◽

Reducing Power ◽

Guaiacol Peroxidase ◽

Salt Stress Tolerance ◽

Sod Activity ◽

Functional Link ◽

Leaves And Roots

Abstract We have previously demonstrated that salt tolerance in cowpea could be associated with lesser impairments of the photosynthetic capacity. Taking into account that photosynthesis is the main sink for reducing power consumption, our central working hypothesis is that a salt-sensitive cultivar is more prone to suffer from oxidative stress. We analyzed the long-term effects of salt stress on oxidative damage and protection against reactive oxygen species in both leaves and roots of a salt-tolerant (Pitiúba) and a salt-sensitive (TVu) cowpea cultivar. Two salt treatments (0 and 75 mM NaCl) were applied to 10-day-old plants grown in nutrient solution for 24 days. Significant salt-induced oxidative damage as demonstrated via increases in malondialdehyde concentration were noted, particularly in leaves at the end of the experiment, although such damage was found earlier in Pitiúba. In salt-stressed plants, superoxide dismutase (SOD) activity increased only in Pitiúba at 24 days from the start of salt additions (DSSA). In Pitiúba, catalase (CAT) was not significantly affected by the treatments, whereas in TVu its activity was dramatically lower in salt-stressed plants at 10DSSAonwards. In general salt stress led to significant increases, much more pronounced in ascorbate peroxidase (APX), glutathione reductase (GR) and guaiacol peroxidase (GPX), at the end of the experiment in both cultivars. In roots, salt-induced increases in enzyme activities were particularly noted at 24 DSSA, as found for SOD and APX in Pitiúba, CAT in TVu and GR and GPX in both cultivars. Therefore, in contrast to our expectations, the present results argue, to a great extent, against a functional link between salt stress tolerance and the expression of the antioxidant system. We also demonstrated that leaves and roots should be evaluated for a full assessment of whole plant acclimation to salt stress.

Download Full-text