Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 9

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Nitric oxide alleviates manganese toxicity by preventing oxidative stress in exised rice leaves

100%
Srivastava S., Dubey R. S.
Acta Physiologiae Plantarum
|
2012
|
tom 34
|
nr 2
In the present study, we have investigated the effects of nitric oxide (NO) on alleviating manganese (Mn)-induced oxidative stress in rice leaves. Exogenous MnCl₂ treatment to excised rice leaves for 24 and 48 h resulted in increased production of H₂O₂ and lipid peroxides, decline in the levels of antioxidants, glutathione and ascorbic acid, and increased activities of antioxidative enzymes, superoxide dismutase, guaiacol peroxidase, catalase, ascorbate peroxidase, dehydroascorbate reductase, and glutathione reductase. Treatment of rice leaves with 100 µM sodium nitroprusside (SNP), a NO donor, was effective in reducing Mn-induced increased levels of H₂O₂, lipid peroxides and increased activities of antioxidative enzymes. The levels of reduced ascorbate and glutathione were considerably recovered due to SNP treatment. The effect of SNP was reversed by the addition of NO scavenger, 2-(4-carboxy-2-phenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (c-PTIO) suggesting that ameliorating effect of SNP is due to release of NO. The results indicate that MnCl₂ induces oxidative stress in excised rice leaves, lowers the levels of reduced ascorbate and glutathione, and elevates activities of the key antioxidative enzymes. NO appears to provide a protection to the rice leaves against Mn-induced oxidative stress and that exogenous NO application could be advantageous in combating the deleterious effects of Mn-toxicity in rice plants.
2

Response of adenine and pyridine metabolism during germination and early seedling growth under arsenic stress in Brassica juncea

81%
Srivastava S., Akkarakan J. J., Suprasanna P., D`Souza S. F.
Acta Physiologiae Plantarum
|
2013
|
tom 35
|
nr 04
Adenine and pyridine nucleotides play vital roles in virtually all aspects of plant growth. This study analyzed the response of adenine and pyridine metabolism during germination and early seedling growth (ESG) of Brassica juncea exposed to two doses of arsenate (AsV), 100 and 250 μM, having non-significant or significant inhibitory effects, respectively, on germination and ESG. The ratio of NAD/NADP and NAD/NADH showed no significant change in control and 100 lM AsV, but increased significantly at 250 μM AsV during initial 24 h and also at 7th day. The activity of enzymes of NAD metabolism, viz. NAD kinase, NADP phosphatase, nicotinamidase and poly(ADP-ribose) polymerases showed significant change mostly at 250 μM AsV. Further, significant decrease was observed in the ratio of ATP/ADP and in the activities of adenylate kinase and apyrase at 250 μM AsV at 7th day. External supply of ATP (1 mM) to 100 and 250 μM AsV significantly improved germination percentage and germination strength of the seeds as compared to AsV treatments alone. The study concludes that with the increase in concentration of AsV, the balance of NAD/NADP, NAD/NADH and ATP/ADP and the activities of enzymes of adenine and pyridine metabolism were significantly altered and that these changes may be responsible for inhibitory effects of AsV on germination and ESG.
3

Evaluation of effects of arsenic on carbon, nitrogen, and sulfur metabolism in two contrasting varieties of Brassica juncea

81%
Pathare V., Srivastava S., Suprasanna P.
Acta Physiologiae Plantarum
|
2013
|
tom 35
|
nr 12
This study evaluated the effects of arsenic (As) exposure on carbon, nitrogen, and sulfur (CNS) metabolism in Brassica juncea. Two contrasting, tolerant (TPM-1) and sensitive (TM-4), varieties of B. Juncea were selected and grown either in control sand (150 g) or in sand containing 10 mg of arsenate. Harvesting was performed at 7 and 15 days and various metabolites and enzymes of CNS as well as γ-aminobutyric acid (GABA) metabolism were analyzed. At 7 days, TM-4 showed significantly higher As accumulation and stressed phenotype with increase in superoxide radicals, malondialdehyde, and cell death, as compared with TPM-1. However, the level of hydrogen peroxide was higher in TPM-1 than in TM-4. The level of GABA and the activity of glutamate decarboxylase increased in both roots and shoots of TPM-1, but not in TM-4. The level of nitrate and sulfate increased and decreased in shoots of TPM-1 and TM-4, respectively. The supply of fumarate and succinate was maintained in both shoots and roots of TPM-1 while it was only in shoots of TM-4. There was significant alteration in the profile of amino acids and in sulfur and nitrogen metabolism. However, at 15 days, As accumulation of both varieties was found to be similar along with an increase in GABA, nitrate, and sulfate in both shoots and roots except sulfate in TM-4. Supply of fumarate and succinate was also maintained and other responses were found to be similar in TPM-1 and TM-4. The study demonstrates that responses of CNS metabolism differ in varietal and time-dependent manner.
4

Arsenic accumulation in Ocimum spp. and its effect on growth and oil constituents

81%
Siddiqui F., Krishna S. K., Tandon P. K., Srivastava S.
Acta Physiologiae Plantarum
|
2013
|
tom 35
|
nr 04
A comparative evaluation of As accumulation and subsequent effects upon exposure to arsenite [As(III)] was performed in three species of Ocimum. Plants accumulated high amount of As (μg g-1 dry weight; dw) (662 in O. tenuiflorum, 764 in O. basilicum and 831 in O. gratissimum at 100 μM As(III) after 10 days) with the order of accumulation being roots[stem[leaves. A significant reduction in plant height and biomass was observed. However, essential oil yield and major oil constituents, such as eugenol, methyl chevicol, and linalool, increased at lower As(III) concentrations [mostly up to 25 μM As(III)] in all three species. Positively, no detectable amount of As was found in oil of any species. The study proposes that Ocimum may be used as a phytoremediator and at the same time as a source of essential oils under proper regulation.
5

Seasonal variation in abiotic factors and toxicity of thymol against the snail Lymnaea acuminata

81%
Srivastava S., Kumar P., Singh V. K., Singh D. K.
Journal of Biology and Earth Sciences
|
2013
|
tom 03
|
nr 1
6

Potential of Saraca indica leaf powder [SILP] for chromium removal from aqueous solution

80%
Goyal P., Sharma P., Srivastava S., Srivastava M. M.
Archiwum Ochrony Środowiska
|
2007
|
tom 33
|
nr 2
7

Impact of excess zinc on growth parameters, cell division, nutrient accumulation, photosynthetic pigments and oxidative stress of sugarcane (Saccharum spp.)

71%
Jain R., Srivastava S., Solomon S., Shrivastava A. K., Chandra A.
Acta Physiologiae Plantarum
|
2010
|
tom 32
|
nr 5
The present study employed a sand culture experiment with three levels of zinc viz., 0.065 (control), 65.0 and 130 mg l⁻¹ Zn (excess) as zinc sulfate, respectively, in sugarcane (Saccharum spp.), cultivar CoLk 8102. The results indicated growth depression, dark green leaves, decreased root number and length and sharp depression in mitotic activity of roots due to high doses of Zn (65 and 130 mg l⁻¹); effects were significant at 130 mg l⁻¹ Zn supply. The endogenous ion contents measurements revealed roots to be the major sink for excess Zn with lower amounts in leaves of sugarcane plants. High level of Zn decreased total phosphorus in leaves and increased it in roots. Fe and Cu content decreased, while, Mn increased in sugarcane plants due to high Zn in the growing medium. Plants experienced oxidative stress when exposed to higher levels of zinc. Biochemical investigations indicated high level of hydrogen peroxide, malondialdehyde contents with high chlorophyll a, b and carotenoids contents and activity of superoxide dismutase, catalase and peroxidase enzymes under high Zn conditions. These findings confirm suggest that excess Zn adversely affects root growth and mitotic efficiency, enhances chromosomal aberrations and increases growth and nutrient accumulation abnormalities, as well as oxidative stress.
8

Adsorption behavior of cadmium and nickel from aqueous solution by Saraca indica leaf powder

71%
Srivastava M. M., Chauhan A., Kumari P., Sharma P., Srivastava S.
Archiwum Ochrony Środowiska
|
2005
|
tom 31
|
nr 3
9

Malachite green-induced changes in carbohydrate metabolism and blood chloride levels in the freshwater catfish Heteropneustes fossilis [Bloch]

71%
Srivastava A. K., Sinha R., Singh N., Roy D., Srivastava S.
Acta Hydrobiologica
|
1995
|
tom 37
|
nr 2
Exposure of the freshwater catfish H. fossilis to an acute concentration of 0.20 mg dm-3 (l/5th of 4 days LC50) of malachite green for 4 days evoked hepatic and muscle glycogenolysis with concomitant hyperglycaemia and chloraemia. Exposure of fish to sub-acute 0.10 mg dm-3 (l/10th of 4 days LC50) and sub-lethal 0.05 mg dm-3 (l/20th of 4 days LC50) concentrations of the dye also evoked a significant increase in blood glucose and chloride levels at short (10-20 days) and long (30-60 days) term as well as liver and muscle glycogenolysis at short term. However, there were no marked changes in the liver glycogen content at the sub-lethal dose or muscle glycogen content at either sub-acute or sub-lethal concentrations for long term exposure.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.