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EDTA reduces cadmium toxicity in mustard (Brassica juncea L.) by enhancing metal chelation, antioxidant defense and glyoxalase systems

100%

Al Mahmud J., Hasanuzzaman M., Nahar K., Rahman A., Fujita M.

Acta Agrobotanica

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2019

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tom 72

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nr 2

To investigate the possible role of EDTA in mitigating cadmium (Cd) toxicity, we treated mustard (Brassica juncea L.) seedlings with CdCl2 (0.5 mM and 1.0 mM, 3 days) alone and in combination with 0.5 mM EDTA in a semihydroponic medium. In the absence of EDTA, mustard seedlings accumulated Cd in their roots and shoots in a concentration dependent manner. Overaccumulation of Cd boosted generation of hydrogen peroxide (H2O2) and superoxide anions (O2•−), increased lipoxygenase (LOX) activity, lipid peroxidation, and cytotoxic methylglyoxal (MG) content. It also disturbed components of the antioxidant defense and glyoxalase systems. Furthermore, Cd stress decreased growth, leaf relative water content (RWC) and chlorophyll (chl) content but augmented the proline (Pro) content. On the other hand, EDTA supplemented Cd-stressed seedlings improved the constituents of the AsA-GSH cycle with the upregulated activities of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT). Moreover, addition of EDTA to the Cd-stressed seedlings notably enhanced Gly I activity in contrast to the stress treatment. Ethylenediaminetetraacetic acid decreased Cd accumulation in the both shoots and roots, as well as increased other nonprotein thiols (NPTs) in leaves, including the phytochelatin (PC) content. It also decreased H2O2 and O2•− generation, lipid peroxidation and MG content but enhanced RWC, chl and Pro contents in the leaves, which confirmed the improved growth of seedlings. The findings of the study suggest that exogenous application of EDTA to the Cd-treated seedlings reduces Cd-induced oxidative injuries by restricting Cd uptake, increasing NPTs concentration and upregulating most of the components of their antioxidant defense and glyoxalase systems.

2

Quercetin-4'-glucoside: a physiological inhibitor of the activities of dominant glutathione S-transferases in onion (Allium cepa L.) bulb

100%

Rohman M. M., Hossain M. D., Suzuki T., Tokada G., Fujita M.

Acta Physiologiae Plantarum

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2009

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tom 31

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nr 2

The onion (Allium cepa L.) bulb has a high level of glutathione S-transferase (GST) activity, and it is a rich source of sulfur compounds as well as flavonoids. To investigate interactions between onion bulb GSTs and metabolites, we separated onion bulb GSTs (GSTa and GSTb as minor GSTs and GSTc, GSTd and GSTe as dominant GSTs) by DEAE-cellulose chromatography. In Western blot analysis with anti-CmGSTF1 antiserum, GSTc and GSTd fractions showed a thick band. A cDNA (AcGSTF1) corresponding to GSTc was immunoscreened with the same antiserum from an onion bulb cDNA library and its bacterial expression product was also subjected to investigation. Among the sulfur compounds, nonphysiological compounds, S-hexyl glutathione (GSH) and S-butyl GSH, showed strong inhibitory effects on 1-chloro-2,4-dinitrobenezene (CDNB)-conjugating activities of GSTa, GSTb and GSTe. However, physiological sulfur compounds, S-methyl GSH, S-propyl GSH, S-lactoyl GSH and S-ethyl-L-cysteine sulfoxide, had small or almost no inhibitory effects. Therefore, onion sulfur compounds might have the least possibility to be substantial inhibitors of onion GSTs. On the other hand, the activities of GSTc, GSTd and AcGSTF1 were strongly inhibited by flavonoids, quercetin, luteolin, apigenin and kaempferol. Ethylacetate (EtOAc) extract of onion bulb contained quercetin-40-glucoside as a major inhibitory substance. The strong inhibitory effects of quercetin-4'-glucoside on GSTc and GSTd as well as on AcGSTF1 (50% inhibitory concentration (IC₅₀): 9.5, 7.5 and 11.2 µM, respectively) along with its high concentration (226 µM) in the onion bulb indicates that quercetin-4'-glucoside is a physiological inhibitor of dominant GSTs in the onion bulb.

3

Exogenous application of gibberellic acid mitigates drought-induced damage in spring wheat

86%

Moumita, Al Mahmud J., Biswas P. K., Nahar K., Fujita M., Hasanuzzaman M.

Acta Agrobotanica

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2019

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tom 72

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nr 2

Drought stress is a major problem in wheat production but it could be managed by using various exogenous protectants such as gibberellic acid (GA). Although GA is a plant growth hormone, it shows a potential to protect the plant in stress conditions. To investigate the possible role of GA in mitigating drought stress, we treated wheat (Triticum aestivum ‘BARI Gom-21’) seedlings with a GA spray under semihydroponic conditions. In the experiment, the combined effect of GA and drought stress (induced by 12% polyethylene glycol) was studied after 48 h and 72 h. In the absence of exogenous GA, drought-stressed wheat seedlings showed various physiological and biochemical changes in a time-dependent manner. Malondialdehyde (MDA), hydrogen peroxide (H2O2) and free proline (Pro) concentrations were increased, whereas catalase (CAT) and ascorbate peroxidase (APX) activities were reduced under drought stress. Gibberellic acid played a role in restoring the ascorbate (AsA) level, decreased the reduced/oxidized glutathione (GSH/GSSG) ratio and reduced monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) activities. Gibberellic acid significantly affected the glyoxalase system. Under drought stress, the methylglyoxal (MG) concentration was increased but GA application stimulated glyoxalase I (Gly I) and glyoxalase II (Gly II) activities to protect the wheat seedlings against stress. The study concluded that the severity of drought stress in wheat depends on the growth stage and it increases with an increase in the duration of stress, whereas exogenous GA helped the seedlings to survive by upregulating antioxidant defense mechanisms and the glyoxalase system.

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A New Deinonychosaurian Track from the Lower Cretaceous Hekou Group, Gansu Province, China

72%

Xing L., Li D., Harris J. D., Bell P. R., Azuma Y., Fujita M., Lee Y.-N., Currie P. J.

Acta Palaeontologica Polonica

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2013

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tom 58

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nr 4

Herein we describe deinonychosaurian (Dinosauria: Theropoda) tracks in the Lower Cretaceous Hekou Group at sites I and II of Liujiaxia Dinosaur National Geopark, Gansu Province, China. The site preserves 71 didactyl tracks, the largest concentration of deinonychosaurian tracks in Asia. The tracks pertain to a new dromaeopodid ichnospecies: Dromaeosauripus yongjingensis ichnosp. nov., which is diagnosed by: a digital pad formula of x−1−3−4−x and a mean divarication angle between digits III and IV of 19°, and having the proximal portion of digit II contacting the anterior margin of a large, rounded metatarsophalangeal pad. Six Dromaeosauripustrackways from site II comprise at least two, and possibly three, turning trackways in which the track maker(s) turned without slowing down. None of the Dromaeosauripus trackways are parallel or closely spaced, suggesting that they were made by solitary track makers. Estimates of dromaeopodid track−maker sizes are between 61–300 cm, well within the size range established by body fossils of both dromaeosaurids and troodontids.

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P2X7 receptor signaling pathway as a therapeutic target for neurodegenerative diseases

72%

Takenouchi T., Sekiyama K., Sekigawa A., Fujita M., Waragai M., Sugama S., Iwamaru Y., Kitani H., Hashimoto M.

Archivum Immunologiae et Therapiae Experimentalis

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2010

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tom 58

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nr 2

91-96

Ograniczanie wyników

EDTA reduces cadmium toxicity in mustard (Brassica juncea L.) by enhancing metal chelation, antioxidant defense and glyoxalase systems

Quercetin-4'-glucoside: a physiological inhibitor of the activities of dominant glutathione S-transferases in onion (Allium cepa L.) bulb

Exogenous application of gibberellic acid mitigates drought-induced damage in spring wheat

A New Deinonychosaurian Track from the Lower Cretaceous Hekou Group, Gansu Province, China

P2X7 receptor signaling pathway as a therapeutic target for neurodegenerative diseases