Abiotic Stress in Plants - Mechanisms and Adaptations, 2011
Glyoxalase System and Reactive Oxygen Species Detoxification System in Plant Abiotic Stress Respo... more Glyoxalase System and Reactive Oxygen Species Detoxification System in Plant Abiotic Stress Response and Tolerance: An Intimate Relationship 237 monooxygenase (AMO) converts acetol to MG (Casazza et al., 1984). Additionally, MG is also formed during the metabolism of aminoacetone (a metabolite of protein). Semicarbazide-sensitive amine oxidase (SSAO) is able to convert aminoacetone into MG (Lyles, 1996). In a bacterial system, MG is primarily produced from DHAP via MG synthase (Cooper, 1984). Degradation of lipid peroxidation products, in animal systems, generates products like 4-hydroxynon-2-enal and MG. Whether these mechanisms of MG formation are contributing to total MG in plants still needs to be established.
High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed to inve... more High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed to investigate the differences in phytochemicals in roots, bark, and leaf of Sclerocarya birrea (marula) for methanol and water extracts that exhibited the best antioxidant activities. As many as 36 compounds were observed in the extracts of these tissues of which 27 phenolic compounds were tentatively identified. The HPLC-MS/MS results showed flavonoid glycosides were prominent in leaf extracts while the galloylated tannins were largely in bark and root extracts. Four flavonoid glycosides that were reported for the first time in the marula leaf have been identified. The HPLC-MS/MS studies also illustrated different degrees (highest degree = 3) of oligomerisation and galloylation of tannins in the bark and root extracts.
The effects of various pulsed electric field (PEF) parameters on the extraction of polyacetylenes... more The effects of various pulsed electric field (PEF) parameters on the extraction of polyacetylenes from carrot slices were investigated. Optimised conditions with regard to electric field strength (1-4 kV/cm), number of pulses (100-1500), pulse frequency (10-200 Hz) and pulse width (10-30 μs) were identified using response surface methodology (RSM) to maximise the extraction of falcarinol (FaOH), falcarindiol (FaDOH) and falcarindiol-3-acetate (FaDOAc) from carrot slices. Data obtained from RSM and experiments fitted significantly (p < 0.0001) the proposed second-order response functions with high regression coefficients (R 2) ranging from 0.82 to 0.75. Maximal FaOH (188%), FaDOH (164.9%) and FaDOAc (166.8%) levels relative to untreated samples were obtained from carrot slices after applying PEF treatments at 4 kV/cm with 100 number of pulses of 10 μs at 10 Hz. The predicted values from the developed quadratic polynomial equation were in close agreement with the actual experimental values with low average mean deviations (E%) ranging from 0.68% to 3.58%.
Abstract The purpose of this study was to assess the synergistic effects of exogenously applied p... more Abstract The purpose of this study was to assess the synergistic effects of exogenously applied proline and glycinebetaine (betaine) in antioxidant defense and methylglyoxal (MG) detoxification system in mung bean seedlings subjected to salt stress (200 mmol$L-1 NaCl, 48 h). ...
A total of 38 phenolic compounds in the solid/liquid extracts of five Lamiaceae spices such as ro... more A total of 38 phenolic compounds in the solid/liquid extracts of five Lamiaceae spices such as rosemary, oregano, sage, basil and thyme were identified in the present study using LC-ESI-MS/MS. These compounds were distributed in four major categories namely hydroxycinnamic acid derivatives, hydroxybenzoic acid derivatives, flavonoids and phenolic terpenes. Among them, the category of flavonoids was the largest with 17
ABSTRACT In the present study, cold-shock (6℃, 5.5 h) induced salinity and drought tolerance and ... more ABSTRACT In the present study, cold-shock (6℃, 5.5 h) induced salinity and drought tolerance and involvement of antioxidative and glyoxalase systems were investigated in mustard (Brassica campestris L.) seedlings. Seven-day-old seedlings were subjected to salt (150 mmol/L NaCl, 48 h) and drought stress (induced by 20% PEG, 48 h) with or without cold pre-treatment. The results showed that both salt and drought stresses abruptly increased the hydrogen peroxide (H2O2) and lipid peroxidation (malondialdehyde, MDA) levels. Ascorbate (AsA), reduced glutathione (GSH) and oxidized glutathione (GSSG) contents, GSH/GSSG ratio and the activitie of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPX), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II) showed both homogeneity and discrepancies in the responses of mustard seedlings to salinity and drought stresses. Drought stress treatment resulted in a significant increase in AsA content. The GSH and GSSG content increased in response to both salt and drought stresses, however, the GSH/GSSG ratio decreased significantly in response to drought stress. Salt stress treatment resulted in a significant increases of APX, MDHAR, GR, GST and Gly I activities, whereas, CAT and Gly II activities decreased. In contrast, drought stress treatment resulted in a significant increase in MDHAR, DHAR, GPX and Gly I activities; whereas, APX, CAT and Gly II activities decreased. Importantly, cold pre-treated salt and drought-stressed seedlings maintained higher level of AsA, GSH contents and GSH/GSSG ratio, higher activities of APX, DHAR, GR, GST, GPX, CAT, Gly I and Gly II, and lower the levels of GSSG, H2O2 and MDA as compared to the control as well as in most cases seedlings subjected to salt and drought stress without cold pre-treatment. Our findings showed that a retention of the imprint of previous stress exposure (short-term cold-shock), induces salt and drought-induced oxidative stress tolerance by modulating antioxidative and glyoxalase systems.
Journal of Plant Science and Molecular Breeding, 2013
A large number of studies have shown the existence of cross-tolerance in plants, but the exact ph... more A large number of studies have shown the existence of cross-tolerance in plants, but the exact physiological and biochemical mechanism(s) is poorly understood. In this study, heat-shock (42 °C, 5 h) induced salinity and drought tolerance and possible involvement of antioxidative and glyoxalase systems were investigated in mustard (Brassica campestris L.) seedlings. Seven-day-old seedlings were subjected to salt (150 mM NaCl, 48 h) and drought stress (induced by 20% PEG, 48 h) with or without heat pretreatment. Both salt and drought stresses led to a severe oxidative stress as indicated by profound increases in hydrogen peroxide (H 2 O 2) and malondialdehyde (MDA) levels. A significant increase in ascorbate (AsA) content was observed in response to drought stress but the glutathione (GSH) and glutathione disulfide (GSSG) contents increased in response to both salt and drought stress. The GSH/GSSG ratio decreased significantly in response to drought stress. Salt stress led to a significant increases of ascorbate peroxidase (APX), glutathione reductase (GR), glutathione S-transferases (GST) activities; whereas, catalase (CAT) and glyoxalase II (Gly II) activities decreased. Drought stress resulted in a significant increase in monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione peroxidase (GPX) and glyoxalase I (Gly I) activities; whereas, CAT and Gly II activities decreased. Seedlings primed with heat-shock positively modulates the activities of APX, DHAR, GR, GST, GPX, CAT, Gly I and Gly II, and maintained lower levels of GSSG, H 2 O 2 and MDA as compared to the control mostly also salt and drought-stressed seedlings. Our results showed that a retention of the imprint of previous stress exposure (heat-shock) protects the plants from salt and drought-induced oxidative stress by stimulation of antioxidative and glyoxalase defense systems.
The present study investigates the possible regulatory role of exogenous nitric oxide (NO) in ant... more The present study investigates the possible regulatory role of exogenous nitric oxide (NO) in antioxidant defense and methylglyoxal (MG) detoxification systems of wheat seedlings exposed to salt stress (150 and 300 mM NaCl, 4 days). Seedlings were pre-treated for 24 h with 1 mM sodium nitroprusside, a NO donor, and then subjected to salt stress. The ascorbate (AsA) content decreased significantly with increased salt stress. The amount of reduced glutathione (GSH) and glutathione disulfide (GSSG) and the GSH/GSSG ratio increased with an increase in the level of salt stress. The glutathione S-transferase (GST) activity increased significantly with severe salt stress (300 mM). The ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT) and glutathione peroxidase (GPX) activities did not show significant changes in response to salt stress. The glutathione reductase (GR), glyoxalase I (Gly I), and glyoxalase II (Gly II) activities decreased upon the imposition of salt stress, especially at 300 mM NaCl, with a concomitant increase in the H 2 O 2 and lipid peroxidation levels. Exogenous NO pretreatment of the seedlings had little influence on the nonenzymatic and enzymatic components compared to the seedlings of the untreated control. Further investigation revealed that NO pre-treatment had a synergistic effect; that is, the pre-treatment increased the AsA and GSH content and the GSH/GSSG ratio, as well as the activities of MDHAR, DHAR, GR, GST, GPX, Gly I, and Gly II in most of the seedlings subjected to salt stress. These results suggest that the exogenous application of NO rendered the plants more tolerant to salinity-induced oxidative damage by enhancing their antioxidant defense and MG detoxification systems.
Physiology and molecular biology of plants : an international journal of functional plant biology, 2010
The present study investigates the possible mediatory role of exogenously applied glycinebetaine ... more The present study investigates the possible mediatory role of exogenously applied glycinebetaine (betaine) and proline on reactive oxygen species (ROS) and methylglyoxal (MG) detoxification systems in mung bean seedlings subjected to cadmium (Cd) stress (1 mM CdCl2, 48 h). Cadmium stress caused a significant increase in glutathione (GSH) and glutathione disulfide (GSSG) content, while the ascorbate (AsA) content decreased significantly with a sharp increase in hydrogen peroxide (H2O2) and lipid peroxidation level (MDA). Ascorbate peroxidase (APX), glutathione S-transferase (GST), glutathione peroxidase (GPX), and glyoxalase I (Gly I) activities were increased in response to Cd stress, while the activities of catalase (CAT), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR) and glyoxalase II (Gly II) were sharply decreased. Exogenous application of 5 mM betaine or 5 mM proline resulted in an increase in GSH and AsA content, maintena...
The present study investigates the regulatory role of exogenous selenium (Se) in the antioxidant ... more The present study investigates the regulatory role of exogenous selenium (Se) in the antioxidant defense and methylglyoxal (MG) detoxification systems in rapeseed seedlings exposed to salt stress. Twelve-day-old seedlings, grown in Petri dishes, were supplemented with selenium (25 μM Na(2)SeO(4)) and salt (100 and 200 mM NaCl) separately and in combination, and further grown for 48 h. The ascorbate (AsA) content of the seedlings decreased significantly with increased salt stress. The amount of reduced glutathione (GSH) and glutathione disulfide (GSSG) increased with an increase in the level of salt stress, while the GSH/GSSG ratio decreased. In addition, the ascorbate peroxidase (APX) and glutathione S-transferase (GST) activity increased significantly with increased salt concentration (both at 100 and 200 mM NaCl), while glutathione peroxidase (GPX) activity increased only at moderate salt stress (100 mM NaCl). Glutathione reductase (GR) activity remained unchanged at 100 mM NaCl, ...
The protective effect of selenium (Se) on antioxidant defense and methylglyoxal (MG) detoxificati... more The protective effect of selenium (Se) on antioxidant defense and methylglyoxal (MG) detoxification systems was investigated in leaves of rapeseed (Brassica napus cv. BINA sharisha 3) seedlings under cadmium (Cd)-induced oxidative stress. Two sets of 11-day-old seedlings were pretreated with both 50 and 100 μM Se (Na(2)SeO(4), sodium selenate) for 24 h. Two concentrations of CdCl(2) (0.5 and 1.0 mM) were imposed separately or on the Se-pretreated seedlings, which were grown for another 48 h. Cadmium stress at any levels resulted in the substantial increase in malondialdehyde and H(2)O(2) levels. The ascorbate (AsA) content of the seedlings decreased significantly upon exposure to Cd stress. The amount of reduced glutathione (GSH) increased only at 0.5 mM CdCl(2), while glutathione disulfide (GSSG) increased at any level of Cd, with concomitant decrease in GSH/GSSG ratio. The activities of ascorbate peroxidase (APX) and glutathione S-transferase (GST) increased significantly with inc...
The potato glycoalkaloids, α-chaconine, α-solanine and solanidine, along with potato peel extract... more The potato glycoalkaloids, α-chaconine, α-solanine and solanidine, along with potato peel extracts were investigated for potential anti-inflammatory effects in vitro. Their potential to reduce two biomarkers of inflammation, cytokine and nitric oxide (NO) productions, were assessed in the stimulated Jurkat and macrophage models, respectively. Cytokine and nitric oxide productions were stimulated in Jurkat and Raw 264.7 macrophages with Concanavalin A (Con A; 25 μg/ml) and lipopolysaccaride (LPS; 1 μg/ml), respectively. Selective concentrations of glycoalkaloids and potato peel extracts were added simultaneously with Con A or LPS for 24h to investigate their potential to reduce inflammatory activity. α-Chaconine and solanidine significantly reduced interleukin-2 (IL-2) and interleukin-8 (IL-8) productions in Con A-induced Jurkat cells. The potato peel extracts did not influence cytokine production. In LPS-stimulated Raw macrophages, α-solanine, solanidine and two potato peel extracts...
Journal of agricultural and food chemistry, Jan 20, 2014
This work examined the resistance of the renin inhibitory, tridecapeptide IRLIIVLMPILMA derived p... more This work examined the resistance of the renin inhibitory, tridecapeptide IRLIIVLMPILMA derived previously from a Palmaria palmata papain hydrolysate, during gastrointestinal (GI) transit. Following simulated GI digestion, breakdown products were identified using mass spectrometry analysis and the known renin and angiotensin I converting enzyme inhibitory dipeptide IR was identified. In vivo animal studies using spontaneously hypertensive rats (SHRs) were used to confirm the antihypertensive effects of both the tridecapeptide IRLIIVLMPILMA and the seaweed protein hydrolysate from which this peptide was isolated. After 24 h, the SHR group fed the P. palmata protein hydrolysate recorded a drop of 34 mm Hg in systolic blood pressure (SBP) from 187 (±0.25) to 153 (± 0.64) mm Hg SBP, while the group fed the tridecapeptide IRLIIVLMPLIMA presented a drop of 33 mm Hg in blood pressure from 187 (±0.95) to 154 (±0.94) mm Hg SBP compared to the SBP recorded at time zero. The results of this st...
Salinity in the form of abiotic stress adversely effects plant growth, development, and productiv... more Salinity in the form of abiotic stress adversely effects plant growth, development, and productivity. Various osmoprotectants are involved in regulating plant responses to salinity; however, the precise role of trehalose (Tre) in this process remains to be further elucidated. The present study investigated the regulatory role of Tre in alleviating salt-induced oxidative stress in hydroponically grown rice seedlings. Salt stress (150 and 250 mM NaCl) for 72 h resulted in toxicity symptoms such as stunted growth, severe yellowing, and leaf rolling, particularly at 250 mM NaCl. Histochemical observation of reactive oxygen species (ROS; O2 (∙-) and H2O2) indicated evident oxidative stress in salt-stressed seedlings. In these seedlings, the levels of lipoxygenase (LOX) activity, malondialdehyde (MDA), H2O2, and proline (Pro) increased significantly whereas total chlorophyll (Chl) and relative water content (RWC) decreased. Salt stress caused an imbalance in non-enzymatic antioxidants, i....
Heavy metal (HM) toxicity is one of the major abiotic stresses leading to hazardous effects in pl... more Heavy metal (HM) toxicity is one of the major abiotic stresses leading to hazardous effects in plants. A common consequence of HM toxicity is the excessive accumulation of reactive oxygen species (ROS) and methylglyoxal (MG), both of which can cause peroxidation of lipids, oxidation of protein, inactivation of enzymes, DNA damage and/or interact with other vital constituents of plant cells. Higher plants have evolved a sophisticated antioxidant defense system and a glyoxalase system to scavenge ROS and MG. In addition, HMs that enter the cell may be sequestered by amino acids, organic acids, glutathione (GSH), or by specific metal-binding ligands. Being a central molecule of both the antioxidant defense system and the glyoxalase system, GSH is involved in both direct and indirect control of ROS and MG and their reaction products in plant cells, thus protecting the plant from HM-induced oxidative damage. Recent plant molecular studies have shown that GSH by itself and its metabolizin...
Background: More than 80% of mammalian protein-coding genes are driven by TATA-less promoters whi... more Background: More than 80% of mammalian protein-coding genes are driven by TATA-less promoters which often show multiple transcriptional start sites (TSSs). However, little is known about the core promoter DNA sequences or mechanisms of transcriptional initiation for this class of promoters.
A new manufacturing method for producing a puffed ginseng-rice snack (PGRS) was developed using g... more A new manufacturing method for producing a puffed ginseng-rice snack (PGRS) was developed using ginseng powder and map rice flour through a steam and compression process (SCP). The physical and sensory properties of the PGRS were characterized. The pellets for puffing were prepared from ginseng powder and map rice flour. The pellets were subjected to 16, 18, and 20% moisture contents and were puffed at 225, 235, and 245°C. The specific volumes of the PGRSs increased with heating temperature and moisture content. However, the breaking strength of the PGRSs decreased. In addition, the SCP imposed special features in the PGRSs that made them more acceptable. The Hunter L-value increased with heating temperature and moisture content. These results indicate that a PGRS with functional additives could be effectively developed into a functional food with the use of a puffing machine, and that the PGRS shows potential as a new snack product.
Nuclear respiratory factor 1 (NRF-1) is one of the key transcriptional activators for nuclear-cod... more Nuclear respiratory factor 1 (NRF-1) is one of the key transcriptional activators for nuclear-coded genes involved in mitochondrial biogenesis and function as well as for many housekeeping genes. A transcriptional co-activator PGC-1 and its related family member PRC have previously been shown to interact with NRF-1 and co-activate NRF-1. We show here that NRF-1 can also directly interact with poly(ADP-ribose) polymerase 1 (PARP-1) and co-purify the PARP-1⅐DNA-PK⅐Ku80⅐Ku70⅐topoisomerase II-containing protein complex. Our in vitro binding experiments show that DNA-binding/ dimerization domain of NRF-1 and the N-terminal half of PARP-1, which contains two Zinc fingers and the auto-modification domain, are responsible for the interaction, and that this interaction occurs with or without PARP-1 poly(ADP-ribosyl)ation (PARylation). DNA-bound NRF-1 can form a complex with PARP-1, suggesting that NRF-1 can recruit the PARP-1⅐DNA-PK⅐Ku80⅐Ku70⅐topoisomerase II-containing protein complex to the promoter. PARP-1 can also PARylate the DNA-binding domain of NRF-1 and negatively regulate NRF-1⅐PARP-1 interaction. Transient transfection and chromatin immunoprecipitation experiments suggest that PARP-1 plays a role during transcriptional activation by NRF-1. Our finding identifies a new aspect of transcriptional regulation used by NRF-1. Nuclear respiratory factor 1 (NRF-1) 2 is a DNA-binding transcription factor that activates genes that are involved in mitochondrial biogenesis and function and other fundamental cellular functions, such as protein translation/turnover, DNA
By-products of plant origin represent an abundant source of bioactive compounds. However, to expl... more By-products of plant origin represent an abundant source of bioactive compounds. However, to exploit these resources commercially relevant strategies for their extraction must be developed. This review focuses on the extraction of bioactive compounds from food by-products of plant origin by a number of novel methods, including pressurised liquid extraction and supercritical CO 2 extraction. In general supercritical CO 2 extraction is most effective for apolar compounds such as carotenoids, while pressurised liquid extraction can be used to extract more polar compounds such as polyphenols. Both techniques are sustainable and green techniques. In addition, pre-treatment of plant by-products by novel non-thermal processing techniques in order to enhance extraction will be highlighted. In general the selection of an appropriate extraction strategy is dependent on the type of compound to be extracted as well as the potential up scaling of the technique.
Abiotic Stress in Plants - Mechanisms and Adaptations, 2011
Glyoxalase System and Reactive Oxygen Species Detoxification System in Plant Abiotic Stress Respo... more Glyoxalase System and Reactive Oxygen Species Detoxification System in Plant Abiotic Stress Response and Tolerance: An Intimate Relationship 237 monooxygenase (AMO) converts acetol to MG (Casazza et al., 1984). Additionally, MG is also formed during the metabolism of aminoacetone (a metabolite of protein). Semicarbazide-sensitive amine oxidase (SSAO) is able to convert aminoacetone into MG (Lyles, 1996). In a bacterial system, MG is primarily produced from DHAP via MG synthase (Cooper, 1984). Degradation of lipid peroxidation products, in animal systems, generates products like 4-hydroxynon-2-enal and MG. Whether these mechanisms of MG formation are contributing to total MG in plants still needs to be established.
High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed to inve... more High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed to investigate the differences in phytochemicals in roots, bark, and leaf of Sclerocarya birrea (marula) for methanol and water extracts that exhibited the best antioxidant activities. As many as 36 compounds were observed in the extracts of these tissues of which 27 phenolic compounds were tentatively identified. The HPLC-MS/MS results showed flavonoid glycosides were prominent in leaf extracts while the galloylated tannins were largely in bark and root extracts. Four flavonoid glycosides that were reported for the first time in the marula leaf have been identified. The HPLC-MS/MS studies also illustrated different degrees (highest degree = 3) of oligomerisation and galloylation of tannins in the bark and root extracts.
The effects of various pulsed electric field (PEF) parameters on the extraction of polyacetylenes... more The effects of various pulsed electric field (PEF) parameters on the extraction of polyacetylenes from carrot slices were investigated. Optimised conditions with regard to electric field strength (1-4 kV/cm), number of pulses (100-1500), pulse frequency (10-200 Hz) and pulse width (10-30 μs) were identified using response surface methodology (RSM) to maximise the extraction of falcarinol (FaOH), falcarindiol (FaDOH) and falcarindiol-3-acetate (FaDOAc) from carrot slices. Data obtained from RSM and experiments fitted significantly (p < 0.0001) the proposed second-order response functions with high regression coefficients (R 2) ranging from 0.82 to 0.75. Maximal FaOH (188%), FaDOH (164.9%) and FaDOAc (166.8%) levels relative to untreated samples were obtained from carrot slices after applying PEF treatments at 4 kV/cm with 100 number of pulses of 10 μs at 10 Hz. The predicted values from the developed quadratic polynomial equation were in close agreement with the actual experimental values with low average mean deviations (E%) ranging from 0.68% to 3.58%.
Abstract The purpose of this study was to assess the synergistic effects of exogenously applied p... more Abstract The purpose of this study was to assess the synergistic effects of exogenously applied proline and glycinebetaine (betaine) in antioxidant defense and methylglyoxal (MG) detoxification system in mung bean seedlings subjected to salt stress (200 mmol$L-1 NaCl, 48 h). ...
A total of 38 phenolic compounds in the solid/liquid extracts of five Lamiaceae spices such as ro... more A total of 38 phenolic compounds in the solid/liquid extracts of five Lamiaceae spices such as rosemary, oregano, sage, basil and thyme were identified in the present study using LC-ESI-MS/MS. These compounds were distributed in four major categories namely hydroxycinnamic acid derivatives, hydroxybenzoic acid derivatives, flavonoids and phenolic terpenes. Among them, the category of flavonoids was the largest with 17
ABSTRACT In the present study, cold-shock (6℃, 5.5 h) induced salinity and drought tolerance and ... more ABSTRACT In the present study, cold-shock (6℃, 5.5 h) induced salinity and drought tolerance and involvement of antioxidative and glyoxalase systems were investigated in mustard (Brassica campestris L.) seedlings. Seven-day-old seedlings were subjected to salt (150 mmol/L NaCl, 48 h) and drought stress (induced by 20% PEG, 48 h) with or without cold pre-treatment. The results showed that both salt and drought stresses abruptly increased the hydrogen peroxide (H2O2) and lipid peroxidation (malondialdehyde, MDA) levels. Ascorbate (AsA), reduced glutathione (GSH) and oxidized glutathione (GSSG) contents, GSH/GSSG ratio and the activitie of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPX), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II) showed both homogeneity and discrepancies in the responses of mustard seedlings to salinity and drought stresses. Drought stress treatment resulted in a significant increase in AsA content. The GSH and GSSG content increased in response to both salt and drought stresses, however, the GSH/GSSG ratio decreased significantly in response to drought stress. Salt stress treatment resulted in a significant increases of APX, MDHAR, GR, GST and Gly I activities, whereas, CAT and Gly II activities decreased. In contrast, drought stress treatment resulted in a significant increase in MDHAR, DHAR, GPX and Gly I activities; whereas, APX, CAT and Gly II activities decreased. Importantly, cold pre-treated salt and drought-stressed seedlings maintained higher level of AsA, GSH contents and GSH/GSSG ratio, higher activities of APX, DHAR, GR, GST, GPX, CAT, Gly I and Gly II, and lower the levels of GSSG, H2O2 and MDA as compared to the control as well as in most cases seedlings subjected to salt and drought stress without cold pre-treatment. Our findings showed that a retention of the imprint of previous stress exposure (short-term cold-shock), induces salt and drought-induced oxidative stress tolerance by modulating antioxidative and glyoxalase systems.
Journal of Plant Science and Molecular Breeding, 2013
A large number of studies have shown the existence of cross-tolerance in plants, but the exact ph... more A large number of studies have shown the existence of cross-tolerance in plants, but the exact physiological and biochemical mechanism(s) is poorly understood. In this study, heat-shock (42 °C, 5 h) induced salinity and drought tolerance and possible involvement of antioxidative and glyoxalase systems were investigated in mustard (Brassica campestris L.) seedlings. Seven-day-old seedlings were subjected to salt (150 mM NaCl, 48 h) and drought stress (induced by 20% PEG, 48 h) with or without heat pretreatment. Both salt and drought stresses led to a severe oxidative stress as indicated by profound increases in hydrogen peroxide (H 2 O 2) and malondialdehyde (MDA) levels. A significant increase in ascorbate (AsA) content was observed in response to drought stress but the glutathione (GSH) and glutathione disulfide (GSSG) contents increased in response to both salt and drought stress. The GSH/GSSG ratio decreased significantly in response to drought stress. Salt stress led to a significant increases of ascorbate peroxidase (APX), glutathione reductase (GR), glutathione S-transferases (GST) activities; whereas, catalase (CAT) and glyoxalase II (Gly II) activities decreased. Drought stress resulted in a significant increase in monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione peroxidase (GPX) and glyoxalase I (Gly I) activities; whereas, CAT and Gly II activities decreased. Seedlings primed with heat-shock positively modulates the activities of APX, DHAR, GR, GST, GPX, CAT, Gly I and Gly II, and maintained lower levels of GSSG, H 2 O 2 and MDA as compared to the control mostly also salt and drought-stressed seedlings. Our results showed that a retention of the imprint of previous stress exposure (heat-shock) protects the plants from salt and drought-induced oxidative stress by stimulation of antioxidative and glyoxalase defense systems.
The present study investigates the possible regulatory role of exogenous nitric oxide (NO) in ant... more The present study investigates the possible regulatory role of exogenous nitric oxide (NO) in antioxidant defense and methylglyoxal (MG) detoxification systems of wheat seedlings exposed to salt stress (150 and 300 mM NaCl, 4 days). Seedlings were pre-treated for 24 h with 1 mM sodium nitroprusside, a NO donor, and then subjected to salt stress. The ascorbate (AsA) content decreased significantly with increased salt stress. The amount of reduced glutathione (GSH) and glutathione disulfide (GSSG) and the GSH/GSSG ratio increased with an increase in the level of salt stress. The glutathione S-transferase (GST) activity increased significantly with severe salt stress (300 mM). The ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT) and glutathione peroxidase (GPX) activities did not show significant changes in response to salt stress. The glutathione reductase (GR), glyoxalase I (Gly I), and glyoxalase II (Gly II) activities decreased upon the imposition of salt stress, especially at 300 mM NaCl, with a concomitant increase in the H 2 O 2 and lipid peroxidation levels. Exogenous NO pretreatment of the seedlings had little influence on the nonenzymatic and enzymatic components compared to the seedlings of the untreated control. Further investigation revealed that NO pre-treatment had a synergistic effect; that is, the pre-treatment increased the AsA and GSH content and the GSH/GSSG ratio, as well as the activities of MDHAR, DHAR, GR, GST, GPX, Gly I, and Gly II in most of the seedlings subjected to salt stress. These results suggest that the exogenous application of NO rendered the plants more tolerant to salinity-induced oxidative damage by enhancing their antioxidant defense and MG detoxification systems.
Physiology and molecular biology of plants : an international journal of functional plant biology, 2010
The present study investigates the possible mediatory role of exogenously applied glycinebetaine ... more The present study investigates the possible mediatory role of exogenously applied glycinebetaine (betaine) and proline on reactive oxygen species (ROS) and methylglyoxal (MG) detoxification systems in mung bean seedlings subjected to cadmium (Cd) stress (1 mM CdCl2, 48 h). Cadmium stress caused a significant increase in glutathione (GSH) and glutathione disulfide (GSSG) content, while the ascorbate (AsA) content decreased significantly with a sharp increase in hydrogen peroxide (H2O2) and lipid peroxidation level (MDA). Ascorbate peroxidase (APX), glutathione S-transferase (GST), glutathione peroxidase (GPX), and glyoxalase I (Gly I) activities were increased in response to Cd stress, while the activities of catalase (CAT), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR) and glyoxalase II (Gly II) were sharply decreased. Exogenous application of 5 mM betaine or 5 mM proline resulted in an increase in GSH and AsA content, maintena...
The present study investigates the regulatory role of exogenous selenium (Se) in the antioxidant ... more The present study investigates the regulatory role of exogenous selenium (Se) in the antioxidant defense and methylglyoxal (MG) detoxification systems in rapeseed seedlings exposed to salt stress. Twelve-day-old seedlings, grown in Petri dishes, were supplemented with selenium (25 μM Na(2)SeO(4)) and salt (100 and 200 mM NaCl) separately and in combination, and further grown for 48 h. The ascorbate (AsA) content of the seedlings decreased significantly with increased salt stress. The amount of reduced glutathione (GSH) and glutathione disulfide (GSSG) increased with an increase in the level of salt stress, while the GSH/GSSG ratio decreased. In addition, the ascorbate peroxidase (APX) and glutathione S-transferase (GST) activity increased significantly with increased salt concentration (both at 100 and 200 mM NaCl), while glutathione peroxidase (GPX) activity increased only at moderate salt stress (100 mM NaCl). Glutathione reductase (GR) activity remained unchanged at 100 mM NaCl, ...
The protective effect of selenium (Se) on antioxidant defense and methylglyoxal (MG) detoxificati... more The protective effect of selenium (Se) on antioxidant defense and methylglyoxal (MG) detoxification systems was investigated in leaves of rapeseed (Brassica napus cv. BINA sharisha 3) seedlings under cadmium (Cd)-induced oxidative stress. Two sets of 11-day-old seedlings were pretreated with both 50 and 100 μM Se (Na(2)SeO(4), sodium selenate) for 24 h. Two concentrations of CdCl(2) (0.5 and 1.0 mM) were imposed separately or on the Se-pretreated seedlings, which were grown for another 48 h. Cadmium stress at any levels resulted in the substantial increase in malondialdehyde and H(2)O(2) levels. The ascorbate (AsA) content of the seedlings decreased significantly upon exposure to Cd stress. The amount of reduced glutathione (GSH) increased only at 0.5 mM CdCl(2), while glutathione disulfide (GSSG) increased at any level of Cd, with concomitant decrease in GSH/GSSG ratio. The activities of ascorbate peroxidase (APX) and glutathione S-transferase (GST) increased significantly with inc...
The potato glycoalkaloids, α-chaconine, α-solanine and solanidine, along with potato peel extract... more The potato glycoalkaloids, α-chaconine, α-solanine and solanidine, along with potato peel extracts were investigated for potential anti-inflammatory effects in vitro. Their potential to reduce two biomarkers of inflammation, cytokine and nitric oxide (NO) productions, were assessed in the stimulated Jurkat and macrophage models, respectively. Cytokine and nitric oxide productions were stimulated in Jurkat and Raw 264.7 macrophages with Concanavalin A (Con A; 25 μg/ml) and lipopolysaccaride (LPS; 1 μg/ml), respectively. Selective concentrations of glycoalkaloids and potato peel extracts were added simultaneously with Con A or LPS for 24h to investigate their potential to reduce inflammatory activity. α-Chaconine and solanidine significantly reduced interleukin-2 (IL-2) and interleukin-8 (IL-8) productions in Con A-induced Jurkat cells. The potato peel extracts did not influence cytokine production. In LPS-stimulated Raw macrophages, α-solanine, solanidine and two potato peel extracts...
Journal of agricultural and food chemistry, Jan 20, 2014
This work examined the resistance of the renin inhibitory, tridecapeptide IRLIIVLMPILMA derived p... more This work examined the resistance of the renin inhibitory, tridecapeptide IRLIIVLMPILMA derived previously from a Palmaria palmata papain hydrolysate, during gastrointestinal (GI) transit. Following simulated GI digestion, breakdown products were identified using mass spectrometry analysis and the known renin and angiotensin I converting enzyme inhibitory dipeptide IR was identified. In vivo animal studies using spontaneously hypertensive rats (SHRs) were used to confirm the antihypertensive effects of both the tridecapeptide IRLIIVLMPILMA and the seaweed protein hydrolysate from which this peptide was isolated. After 24 h, the SHR group fed the P. palmata protein hydrolysate recorded a drop of 34 mm Hg in systolic blood pressure (SBP) from 187 (±0.25) to 153 (± 0.64) mm Hg SBP, while the group fed the tridecapeptide IRLIIVLMPLIMA presented a drop of 33 mm Hg in blood pressure from 187 (±0.95) to 154 (±0.94) mm Hg SBP compared to the SBP recorded at time zero. The results of this st...
Salinity in the form of abiotic stress adversely effects plant growth, development, and productiv... more Salinity in the form of abiotic stress adversely effects plant growth, development, and productivity. Various osmoprotectants are involved in regulating plant responses to salinity; however, the precise role of trehalose (Tre) in this process remains to be further elucidated. The present study investigated the regulatory role of Tre in alleviating salt-induced oxidative stress in hydroponically grown rice seedlings. Salt stress (150 and 250 mM NaCl) for 72 h resulted in toxicity symptoms such as stunted growth, severe yellowing, and leaf rolling, particularly at 250 mM NaCl. Histochemical observation of reactive oxygen species (ROS; O2 (∙-) and H2O2) indicated evident oxidative stress in salt-stressed seedlings. In these seedlings, the levels of lipoxygenase (LOX) activity, malondialdehyde (MDA), H2O2, and proline (Pro) increased significantly whereas total chlorophyll (Chl) and relative water content (RWC) decreased. Salt stress caused an imbalance in non-enzymatic antioxidants, i....
Heavy metal (HM) toxicity is one of the major abiotic stresses leading to hazardous effects in pl... more Heavy metal (HM) toxicity is one of the major abiotic stresses leading to hazardous effects in plants. A common consequence of HM toxicity is the excessive accumulation of reactive oxygen species (ROS) and methylglyoxal (MG), both of which can cause peroxidation of lipids, oxidation of protein, inactivation of enzymes, DNA damage and/or interact with other vital constituents of plant cells. Higher plants have evolved a sophisticated antioxidant defense system and a glyoxalase system to scavenge ROS and MG. In addition, HMs that enter the cell may be sequestered by amino acids, organic acids, glutathione (GSH), or by specific metal-binding ligands. Being a central molecule of both the antioxidant defense system and the glyoxalase system, GSH is involved in both direct and indirect control of ROS and MG and their reaction products in plant cells, thus protecting the plant from HM-induced oxidative damage. Recent plant molecular studies have shown that GSH by itself and its metabolizin...
Background: More than 80% of mammalian protein-coding genes are driven by TATA-less promoters whi... more Background: More than 80% of mammalian protein-coding genes are driven by TATA-less promoters which often show multiple transcriptional start sites (TSSs). However, little is known about the core promoter DNA sequences or mechanisms of transcriptional initiation for this class of promoters.
A new manufacturing method for producing a puffed ginseng-rice snack (PGRS) was developed using g... more A new manufacturing method for producing a puffed ginseng-rice snack (PGRS) was developed using ginseng powder and map rice flour through a steam and compression process (SCP). The physical and sensory properties of the PGRS were characterized. The pellets for puffing were prepared from ginseng powder and map rice flour. The pellets were subjected to 16, 18, and 20% moisture contents and were puffed at 225, 235, and 245°C. The specific volumes of the PGRSs increased with heating temperature and moisture content. However, the breaking strength of the PGRSs decreased. In addition, the SCP imposed special features in the PGRSs that made them more acceptable. The Hunter L-value increased with heating temperature and moisture content. These results indicate that a PGRS with functional additives could be effectively developed into a functional food with the use of a puffing machine, and that the PGRS shows potential as a new snack product.
Nuclear respiratory factor 1 (NRF-1) is one of the key transcriptional activators for nuclear-cod... more Nuclear respiratory factor 1 (NRF-1) is one of the key transcriptional activators for nuclear-coded genes involved in mitochondrial biogenesis and function as well as for many housekeeping genes. A transcriptional co-activator PGC-1 and its related family member PRC have previously been shown to interact with NRF-1 and co-activate NRF-1. We show here that NRF-1 can also directly interact with poly(ADP-ribose) polymerase 1 (PARP-1) and co-purify the PARP-1⅐DNA-PK⅐Ku80⅐Ku70⅐topoisomerase II-containing protein complex. Our in vitro binding experiments show that DNA-binding/ dimerization domain of NRF-1 and the N-terminal half of PARP-1, which contains two Zinc fingers and the auto-modification domain, are responsible for the interaction, and that this interaction occurs with or without PARP-1 poly(ADP-ribosyl)ation (PARylation). DNA-bound NRF-1 can form a complex with PARP-1, suggesting that NRF-1 can recruit the PARP-1⅐DNA-PK⅐Ku80⅐Ku70⅐topoisomerase II-containing protein complex to the promoter. PARP-1 can also PARylate the DNA-binding domain of NRF-1 and negatively regulate NRF-1⅐PARP-1 interaction. Transient transfection and chromatin immunoprecipitation experiments suggest that PARP-1 plays a role during transcriptional activation by NRF-1. Our finding identifies a new aspect of transcriptional regulation used by NRF-1. Nuclear respiratory factor 1 (NRF-1) 2 is a DNA-binding transcription factor that activates genes that are involved in mitochondrial biogenesis and function and other fundamental cellular functions, such as protein translation/turnover, DNA
By-products of plant origin represent an abundant source of bioactive compounds. However, to expl... more By-products of plant origin represent an abundant source of bioactive compounds. However, to exploit these resources commercially relevant strategies for their extraction must be developed. This review focuses on the extraction of bioactive compounds from food by-products of plant origin by a number of novel methods, including pressurised liquid extraction and supercritical CO 2 extraction. In general supercritical CO 2 extraction is most effective for apolar compounds such as carotenoids, while pressurised liquid extraction can be used to extract more polar compounds such as polyphenols. Both techniques are sustainable and green techniques. In addition, pre-treatment of plant by-products by novel non-thermal processing techniques in order to enhance extraction will be highlighted. In general the selection of an appropriate extraction strategy is dependent on the type of compound to be extracted as well as the potential up scaling of the technique.
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Papers by Mohammad Faroque Hossain