scholarly journals High Oxygen Level in a Soaking Treatment Improves Early Root and Shoot Development of Black Willow Cuttings

2004 ◽  
Vol 4 ◽  
pp. 899-907 ◽  
Author(s):  
L.T. Martin ◽  
S.R. Pezeshki ◽  
F.D. Shields
Keyword(s):  
Biomass Production ◽  
Shoot Growth ◽  
Rapid Development ◽  
High Oxygen ◽  
Stem Cuttings ◽  
Low Oxygen ◽  
Growth And Survival ◽  
Black Willow ◽  
Shoot Initiation ◽  
High Oxygen Level

Black willow (Salix nigra) stem cuttings are commonly used to stabilize eroded streambanks with survival dependent on rapid development of adventitious roots to maintain plant water balance, absorb nutrients, and provide anchorage and support especially during flood and drought events. Soaking cuttings in water prior to planting increases survival and growth rates, but it is not known whether oxygen content in the soaking water affects the rate of early root and shoot initiation and growth. A laboratory experiment tested the hypothesis that cuttings treated with high oxygen (>95% saturation, 8.62 mg O2l–-1) soaking exhibit more rapid initiation and growth of roots and shoots than cuttings treated with low oxygen (<15% saturation, 1.24 mg O2l-1) soaking and control (unsoaked). Root initiation was enhanced in both high and low O2soaking treatments compared to control (100, 93, and 41%, respectively, n = 27). High O2soaking led to greater root length than low O2soaking during the fourth week after planting (26.5 and 12.3 cm on day 22; 27.7 and 19.1 cm on day 27, respectively). Shoot growth was greater in high O2compared to low O2soaking on days 36 and 56 after planting (9.3 and 6.3 cm on day 36, 10.7 and 7.2 cm on day 56, respectively). Shoot and root biomass production was stimulated in both soaking treatments, with 200% more biomass production by day 59 compared to control. Results of this study demonstrated that a high oxygen soaking treatment has potential for improving early root and shoot growth, and survival in willow cuttings planted at riparian restoration sites.

scholarly journals Root Growth of Avocado is More Sensitive to Salinity than Shoot Growth

2004 ◽  
Vol 129 (2) ◽  
pp. 188-192 ◽  
Author(s):  
N. Bernstein ◽  
A. Meiri ◽  
M. Zilberstaine
Keyword(s):  
Salt Stress ◽  
Root Growth ◽  
Biomass Production ◽  
Root Elongation ◽  
Shoot Growth ◽  
Elongation Rate ◽  
Persea Americana ◽  
Root Growth Inhibition ◽  
Leaf Biomass ◽  
Volumetric Growth

In most crop species, growth of the shoot is more sensitive to salt stress than root growth. Avocado [Persea americana Mill.] is very sensitive to NaCl stress. Even low concentrations of salt (15 mm) inhibit tree growth and decrease productivity. Observations in experimental orchards have suggested that root growth in avocado might be more restricted by salinity than shoot growth. In the present study, we evaluated quantitatively the inhibitory effects of salt stress on growth of the avocado root in comparison to the shoot. Seedling plants of the West-Indian rootstock `Degania 117' were grown in complete nutrient solution containing 1, 5, 15, or 25 mm NaCl. The threshold NaCl concentration causing root and shoot growth reduction occurred between 5 and 15 mm. At all concentrations, root growth was much more sensitive to salinity than shoot growth. A concentration of 15 mm NaCl, which did not affect the rate of leaf emergence on the plant and decreased leaf biomass production only 10%, induced a 43% reduction in the rate of root elongation and decreased root volumetric growth rate by 33%. Under 25 mm NaCl, leaf biomass production, leaf initiation rate and leaf elongation rate were reduced 19.5%, 12%, and 5%, respectively, while root volumetric growth and root elongation rate were reduced 65% and 75%, respectively. This strong root growth inhibition is expected to influence the whole plant and therefore root growth under salinity should be considered as an important criterion for rootstocks' tolerance to NaCl.

Fine Temporal Mapping of Plasmodium Falciparum growth Inhibition in Hypoxic Sickle Cell Trait Erythrocytes

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 924-924
Author(s):  
Natasha Archer ◽  
Nicole Petersen ◽  
Martha Clark ◽  
Manoj Duraisingh
Keyword(s):  
Flow Cytometry ◽  
Carbon Monoxide ◽  
Dna Replication ◽  
Oxygen Tension ◽  
Sickle Cell ◽  
Sickle Cell Trait ◽  
High Oxygen ◽  
Low Oxygen ◽  
Trophozoite Stage ◽  
Sickle Hemoglobin

Abstract Background: Despite the global acceptance of Haldane's hypothesis that individuals with sickle cell trait (AS) are protected against malaria, an exact mechanism of resistance remains unknown. Several theories to explain the resistance such as increased splenic destruction, impaired hemoglobin digestion, reduced cytoadherence and specific translocation of host specific microRNAs have been proposed. Here we carefully examine the influence of hypoxia and its relation to parasite cytoadherence and growth in AS and normal (AA) human red blood cells (RBCs). Materials and Methods: To assess the influence of oxygen tension on parasite proliferation in AS RBCs, we followed the proliferation of tightly synchronized P. falciparum within AS and AA RBCs at 1, 5, 10, and 17% oxygen by flow cytometry and microscopy. Carbon monoxide (CO) studies were performed by introducing 100% CO gas into our enclosed chamber system every 21 hours to prevent sickling at low oxygen. Results: Flow cytometry assessment of DNA content confirms the absence of DNA replication within parasites in AS erythrocytes at low oxygen, however normal DNA replication is observed in the presence of high oxygen tension and when CO is introduced at low oxygen. Moving parasites from high to low oxygen tension greatly influences the extent of parasite maturity; parasites moved at 16 and 20 hours post invasion (hpi) do not mature beyond that of the late ring/early trophozoite stage while parasites moved at 24, 28, and 32 hpi develop increasingly more merozoites. Conclusion: Here, we show that in hypoxic conditions parasites in AS erythrocytes stall at the late ring/early trophozoite stage and do not replicate their DNA. We also show that treatment of AS erythrocytes with high oxygen tension or carbon monoxide, a potent inhibitor of sickle hemoglobin polymerization, reverses this phenotype. We propose that the mechanism of AS protection is largely due to P.falciparum's inability to digest polymerized sickle hemoglobin once the parasite sequesters in the hypoxic microvasculature. This is likely a key driver of the reduced parasite densities observed in actual infections in AS individuals. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals Testing of microbial additives in the rooting of Norway spruce (Picea abies [L.] Karst.) stem cuttings

2011 ◽  
Vol 57 (No. 12) ◽  
pp. 555-564 ◽  
Author(s):  
I. Repáč ◽  
J. Vencurik ◽  
M. Balanda
Keyword(s):  
Norway Spruce ◽  
Shoot Growth ◽  
Growth Parameters ◽  
Alginate Bead ◽  
Block Design ◽  
The Other ◽  
Stem Cuttings ◽  
Naturally Occurring ◽  
Randomized Complete Block Design ◽  
Ecm Fungi

&nbsp;Laboratory-produced alginate-bead inoculum of ectomycorrhizal (ECM) fungi Cortinarius sp. and&nbsp;Gomphidius glutinosus, fungal commercial products ECtovit<sup>&reg; </sup>and Trichomil<sup>&reg;</sup>, bacterial commercial product BactoFil&nbsp;B<sup>&reg;</sup>, and commercial rooting stimulator Vetozen<sup>&reg;</sup> were applied to a peat-perlite (1:2, v:v) rooting substrate of Norway spruce stem cuttings collected from 4-year-old nursery-grown seedlings immediately before the insertion of cuttings into the substrate. The application of beads free of fungi and the substrate without an additive were the other treatments. The cuttings were rooted in vessels (60 cuttings per vessel, 180 per treatment) placed in a glasshouse and arranged in a randomized complete block design. The cuttings were estimated for one growing season (approximately for 26 weeks) after their insertion into the rooting substrate. Rooting % of the cuttings ranged from 45 (mycelium-free beads) to 75 (control) according to treatments, 64 on average. No significant differences among treatments were found in % of ECM morphotypes, total ECM colonization of roots (%), and growth parameters of shoots and roots of the cuttings. The applied microbial additives were not sufficiently efficient to form treatment-related ectomycorrhizas that were formed by naturally occurring ECM fungi. Inoculation by the ECM fungus Cortinarius sp. and application of Trichomil had a partial stimulative effect on the shoot growth of cuttings. Shoot and root growth parameters were not significantly correlated with total ECM colonization, except for a negative dependence of the root number in Trichomil treatment. A higher concentration of K but lower concentrations of Ca and Mg in Ectovit treatment than in the other treatments were detected.&nbsp; &nbsp;

323 INTERACTIONS OF OXYGEN TENSION, GLUCOSE CONCENTRATION, AND HEAT SHOCK ON MATURATION OF BOVINE OOCYTES

2006 ◽  
Vol 18 (2) ◽  
pp. 269
Author(s):  
L. A. de Castro e Paula ◽  
P. J. Hansen
Keyword(s):  
Heat Shock ◽  
Oxygen Tension ◽  
High Glucose ◽  
Glucose Concentration ◽  
High Oxygen ◽  
High Glucose Concentration ◽  
Blastocyst Formation ◽  
Low Oxygen ◽  
Main Effects ◽  
Bovine Oocytes

In many cell types, oxygen tension and glucose concentration affect the magnitude of heat shock effects. Experiments were performed to (1) develop oocyte maturation protocols under high (20.95%) and low (5%) oxygen tensions, and (2) test the hypothesis that low oxygen tension and high glucose concentration reduce the magnitude of the deleterious effects of heat shock on in vitro maturation of bovine oocytes. In Experiment 1, oocytes were matured in tissue culture medium-199 (TCM-199) or synthetic oviduct fluid (SOF) containing 5.6 or 20 mM glucose, under either high or low oxygen. Fertilization was performed under high oxygen and embryos were cultured in KSOM-BE2 under low oxygen. Data were analyzed by least squares analysis of variance using the GLM procedure of SAS (SAS Institute, Inc., Cary, NC, USA), with maturation medium, glucose concentration, and oxygen tension as main effects. Oxygen concentration affected percent blastocyst formation when TCM-199 was used (greater for high oxygen than low oxygen) but not when SOF was used (medium � oxygen, P < 0.05). Similarly, glucose had no effect on percent blastocyst formation under high oxygen but high glucose was superior under low oxygen (glucose � oxygen, P < 0.05). Therefore, SOF with either 5.6 or 20 mM glucose was used to study the effect of heat shock on maturation under high and low oxygen in Experiment 2. Maturation was at 38.5�C for 22 h (control) or 41�C for 12 h and 38.5�C for 10 h (heat shock). Fertilization was performed at 38.5�C under high oxygen and embryos were cultured in KSOM-BE2 under low oxygen at 38.5�C. Data were analyzed as described above with glucose concentration, temperature and oxygen tension as main effects. The experiment was replicated nine times with a total of 3215 embryos. Heat shock decreased the cleavage rate slightly regardless of the maturation conditions (69 � 1% vs. 66 � 1%, P < 0.01). For oocytes matured in 5.6 mM glucose, percent blastocyst formation was greater for high oxygen while there was no effect of oxygen tension for oocytes matured in 20 mM glucose (glucose � oxygen, P < 0.01). Heat shock decreased the percent blastocyst formation under all maturation conditions except for the group matured under high oxygen and high glucose (temperature � oxygen � medium, P = 0.07; temperature � oxygen for oocytes under 5% oxygen; P < 0.05). The percent blastocyst formation for control and heat-shocked oocytes was 25.9% vs. 22.5% (low oxygen-5.6 mM glucose), 41.6% vs. 34.9% (low-20 mM), 41.7% vs. 35.0% (high-5.6 mM), and 37.6% vs. 37.5% (high-20 mM) (SEM = 2.0%). In conclusion, heat shock during maturation under an oxygen tension (5% oxygen) that approaches physiological conditions reduces the percent blastocyst formation. Moreover, a high glucose concentration protects oocytes from heat shock under high oxygen. This work was supported by USDA NRICGP 2002-35203-12664 and CAPES #134202-9.

scholarly journals Hypoxia increases the risk of egg predation in a nest-guarding fish

2016 ◽  
Vol 3 (8) ◽  
pp. 160326 ◽  
Author(s):  
Karin H. Olsson ◽  
Charlotta Kvarnemo ◽  
Maria Norevik Andrén ◽  
Therése Larsson
Keyword(s):  
Carcinus Maenas ◽  
High Oxygen ◽  
Filial Cannibalism ◽  
Defensive Behaviour ◽  
Low Oxygen ◽  
Pomatoschistus Minutus ◽  
Oxygen Treatment ◽  
Large Nest ◽  
Shore Crabs ◽  
Egg Guarding

For fish with parental care, a nest should meet both the oxygenation needs of the eggs and help protect them against predators. While a small nest opening facilitates the latter, it impedes the former and vice versa. We investigated how the presence of potential egg predators in the form of shore crabs Carcinus maenas affects nest building, egg fanning, defensive displays and filial cannibalism of egg-guarding male sand gobies Pomatoschistus minutus under two levels of dissolved oxygen. In the high oxygen treatment, males retained their nest opening size in the presence of crabs, while males in low oxygen built large nest openings both in the absence and presence of crabs, despite the fact that crabs were more likely to successfully intrude into nests with large entrances. Males in low oxygen also fanned more. In the presence of crabs males increased their defensive displays, but while males in high oxygen reduced fanning, males in low oxygen did not. Filial cannibalism was unaffected by treatment. Sand gobies thus prioritize egg ventilation over the protection afforded by small nest openings under hypoxia and adopt defensive behaviour to avert predator attention, even though this does not fully offset the threat from the egg predators.

Getter Effects in Low Oxygen and High Oxygen Czochralski Silicon Wafers

2019 ◽  
Vol 33 (11) ◽  
pp. 113-120 ◽  
Author(s):  
Gudrun Kissinger ◽  
Dawid Kot ◽  
Walter Häckl
Keyword(s):  
Silicon Wafers ◽  
High Oxygen ◽  
Low Oxygen ◽  
Czochralski Silicon
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