Iron redox cycling, sediment resuspension and the role of sediments in low oxygen environments as sources of iron to the water column

Low oxygen level is a phenomenon often occurring during the cucumber cultivation period. Genes involved in adaptations to stress can be regulated by non-coding RNA. The aim was the identification of long non-coding RNAs (lncRNAs) involved in the response to long-term waterlogging stress in two cucumber haploid lines, i.e., DH2 (waterlogging tolerant—WL-T) and DH4 (waterlogging sensitive—WL-S). Plants, at the juvenile stage, were waterlogged for 7 days (non-primed, 1xH), and after a 14-day recovery period, plants were stressed again for another 7 days (primed, 2xH). Roots were collected for high-throughput RNA sequencing. Implementation of the bioinformatic pipeline made it possible to determine specific lncRNAs for non-primed and primed plants of both accessions, highlighting differential responses to hypoxia stress. In total, 3738 lncRNA molecules were identified. The highest number (1476) of unique lncRNAs was determined for non-primed WL-S plants. Seventy-one lncRNAs were depicted as potentially being involved in acquiring tolerance to hypoxia in cucumber. Understanding the mechanism of gene regulation under long-term waterlogging by lncRNAs and their interactions with miRNAs provides sufficient information in terms of adaptation to the oxygen deprivation in cucumber. To the best of our knowledge, this is the first report concerning the role of lncRNAs in the regulation of long-term waterlogging tolerance by priming application in cucumber.

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Seasonal variations of water column nutrients in the inner area of Ariake Bay, Japan: the role of muddy sediments

Environmental Monitoring and Assessment ◽

10.1007/s10661-013-3068-8 ◽

2013 ◽

Vol 185 (8) ◽

pp. 6831-6846 ◽

Cited By ~ 7

Author(s):

Masumi Koriyama ◽

Yuichi Hayami ◽

Akane Koga ◽

Koichi Yamamoto ◽

Alim Isnasetyo ◽

...

Keyword(s):

Water Column ◽

Seasonal Variations ◽

Ariake Bay ◽

Muddy Sediments

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NADPH oxidase-derived ROS and the regulation of pulmonary vessel tone

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00780.2011 ◽

2012 ◽

Vol 302 (11) ◽

pp. H2166-H2177 ◽

Cited By ~ 48

Author(s):

G. Frazziano ◽

H. C. Champion ◽

P. J. Pagano

Keyword(s):

Oxygen Tension ◽

Vascular Tone ◽

Systemic Circulation ◽

Oxygen Species ◽

Partial Pressure Of Oxygen ◽

Low Oxygen ◽

Key Factors ◽

Pulmonary Vessel ◽

Major Emphasis

Pulmonary vessel constriction results from an imbalance between vasodilator and vasoconstrictor factors released by the endothelium including nitric oxide, endothelin, prostanoids, and reactive oxygen species (ROS). ROS, generated by a variety of enzymatic sources (such as mitochondria and NADPH oxidases, a.k.a. Nox), appear to play a pivotal role in vascular homeostasis, whereas elevated levels effect vascular disease. The pulmonary circulation is very sensitive to changes in the partial pressure of oxygen and differs from the systemic circulation in its response to this change. In fact, the pulmonary vessels contract in response to low oxygen tension, whereas systemic vessels dilate. Growing evidence suggests that ROS production and ROS-related pathways may be key factors that underlie this differential response to oxygen tension. A major emphasis of our laboratory is the role of Nox isozymes in cardiovascular disease. In this review, we will focus our attention on the role of Nox-derived ROS in the control of pulmonary vascular tone.

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Effects of Fe addition on sediment P dynamics in a eutrophic lake

10.5194/egusphere-egu21-4941 ◽

2021 ◽

Author(s):

Melanie Münch ◽

Rianne van Kaam ◽

Karel As ◽

Stefan Peiffer ◽

Gerard ter Heerdt ◽

...

Keyword(s):

Water Quality ◽

Organic Matter ◽

Surface Water ◽

Water Column ◽

Sediment Cores ◽

Surface Water Quality ◽

Water Interface ◽

Eutrophic Lakes ◽

Fe Addition

The decline of surface water quality due to excess phosphorus (P) input is a global problem of increasing urgency. Finding sustainable measures to restore the surface water quality of eutrophic lakes with respect to P, other than by decreasing P inputs, remains a challenge. The addition of iron (Fe) salts has been shown to be effective in removing dissolved phosphate from the water column of eutrophic lakes. However, the resulting changes in biogeochemical processes in sediments as well as the long-term effects of Fe additions on P dynamics in both sediments and the water column are not well understood.In this study, we assess the impact of past Fe additions on the sediment P biogeochemistry of Lake Terra Nova, a well-mixed shallow peat lake in the Netherlands. The Fe-treatment in 2010 efficiently reduced P release from the sediments to the surface waters for 6 years. Since then, the internal sediment P source in the lake has been increasing again with a growing trend over the years.In 2020, we sampled sediments at three locations in Terra Nova, of which one received two times more Fe during treatment than the other two. Sediment cores from all sites were sectioned under oxygen-free conditions. Both the porewaters and sediments were analysed for their chemical composition, with sequential extractions providing insight into the sediment forms of P and Fe. Additional sediment cores were incubated under oxic and anoxic conditions and the respective fluxes of P and Fe across the sediment water interface were measured.The results suggest that Fe and P dynamics in the lake sediments are strongly coupled. We also find that the P dynamics are sensitive to the amount of Fe supplied, even though enhanced burial of P in the sediment was not detected. The results of the sequential extraction procedure for P, which distinguishes P associated with humic acids and Fe oxides, as well as reduced flux of Fe(II) across the sediment water interface in the anoxic incubations, suggest a major role of organic matter in the interaction of Fe and P in these sediments.Further research will include investigations of the role of organic matter and sulphur in determining the success of Fe-treatment in sequestering P in lake sediments. Based on these data in combination with reactive transport modelling we aim to constrain conditions for successful lake restoration through Fe addition.

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Zooplankton fluctuations in Jurumirim Reservoir (São Paulo, Brazil): a three-year study

Brazilian Journal of Biology ◽

10.1590/s1519-69842009000100002 ◽

2009 ◽

Vol 69 (1) ◽

pp. 1-18 ◽

Cited By ~ 23

Author(s):

LP. Sartori ◽

MG. Nogueira ◽

R. Henry ◽

EM. Moretto

Keyword(s):

Water Column ◽

Oxygen Concentration ◽

Retention Time ◽

Sao Paulo ◽

Seasonal Effect ◽

São Paulo ◽

Low Oxygen ◽

High Concentration ◽

Heterogeneous Distribution ◽

Low Oxygen Concentration

During three consecutive years, monthly samples of zooplankton were taken in the lacustrine (dam) zone of Jurumirim (São Paulo, Brazil). The seasonal effect on basic limnological features (thermal regime, oxygen distribution, phytoplankton biomass, etc.) was also examined. The influence of the seasonality on the fluctuation of the zooplankton composition and abundance was not clearly detected (low degree of recurrent patterns). Rotifers (32 taxa) were the most abundant organisms during almost the entire study period with some seasonal alternations in the maximum abundance peaks of the main taxa (Conochilus unicornis, Keratella americana, K. cochlearis and Hexarthra spp.), except for Polyarthra (mainly P. vulgaris). Only occasionally copepods were numerically dominant. Higher copepod abundance was positively associated to periods of increase in the water retention time. Among the Copepoda (10 taxa) the calanoids (mainly Notodiaptomus iheringi) were more abundant, especially in warmer periods. Conversely, cyclopoids had higher abundance in autumn and winter. The species Thermocyclops minutus and T. decipiens co-occurred, but the first attained higher abundance. Some evidence of co-existence strategies between both species are considered. Cladocera (17 taxa) was never numerically dominant and the main taxa (Bosmina spp., Ceriodaphnia spp. and Diaphanosoma spp.) occurred almost the whole study period and did not present a seasonal pattern of fluctuation. Diaphanosoma (mainly D. birgei) attained the highest abundance among cladocerans. Most organisms were always found at the surface, but they also occupy the whole water column, even in periods of stratified conditions and low oxygen concentration in the bottom layers. Among the main zooplanktonic taxa, only Hexarthra avoids deep layers. An exceptionally high concentration of Copepoda nauplii on the surface was influenced by low transparency, high concentration of phytoplankton at this layer and low oxygen concentration at the bottom. In periods of higher retention timevariability there was a more heterogeneous distribution of the zooplankton in the water column. The increase in the retention time seems also to favor the copepod development. Finally, some inter-decade changes are considered on the basis of zooplankton assemblage structure observations.

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Behaviour in flow: perspectives on the distribution and dispersion of meroplanktonic larvae in the water column

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f00-159 ◽

2001 ◽

Vol 58 (1) ◽

pp. 86-98 ◽

Cited By ~ 88

Author(s):

Anna Metaxas

Keyword(s):

Water Column ◽

Turbulent Flows ◽

Larval Dispersal ◽

Spatial Scales ◽

Fluid Motion ◽

Benthic Boundary Layer ◽

Larval Distribution ◽

Physical Measurements ◽

Marine Benthic Invertebrates

For marine benthic invertebrates with meroplanktonic larvae, the relative importance of hydrodynamics and swimming behaviour in determining larval dispersal in the water column, particularly at small spatial scales, has not been determined. In the field, larval aggregations recorded at physical and biological discontinuities in the water column were attributed to hydrodynamics. Similar aggregations obtained in the absence of flow in the laboratory indicate a potentially significant role of behaviour. At large spatial scales, larval distribution in the plankton is mainly regulated by horizontal advection. However, the ability of larvae to behaviourally regulate their position at scales of micrometres to metres when exposed to turbulent fluid motion in the water column, as evidenced in the benthic boundary layer, is unknown. Evaluation of swimming in turbulent flows in the water column is an intriguing area of research, which involves several constraints. In the field, quantification of behaviour is limited by low success in tracking larvae and lack of appropriate observational tools. In the laboratory, the generation and quantification of flow regimes that are representative of those in the field remains a challenge. An approach that integrates biological and physical measurements within realistic ranges is necessary to advance our understanding of larval dispersal.

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Protozoa abundance, growth, and bacterivory in the water column, on sedimenting particles, and in the sediment of Halifax Harbor

Canadian Journal of Microbiology ◽

10.1139/m90-149 ◽

1990 ◽

Vol 36 (12) ◽

pp. 859-863 ◽

Cited By ~ 6

Author(s):

James A. Novitsky

Keyword(s):

Bacterial Community ◽

Water Column ◽

Sediment Surface ◽

Metabolic Inhibitor ◽

Optimum Conditions ◽

Bacterial Populations ◽

Protozoan Grazing ◽

Large Numbers ◽

Doubling Times

The role of protozoan grazing in controlling bacterial populations was examined in four microbial habitats in Halifax Harbor, Canada: the water column, setting particles, the sediment–water interface, and the sediment. Large numbers of protozoans were found in all habitats although most (>56%) were small (<5 μm) flagellates. Protozoans larger than 10 μm were rarely observed; protozoans >20 μm were never observed. Protozoans were also observed to a depth of 9 cm below the sediment surface although efforts to culture viable protozoa failed except for the top 1 cm. The use of the metabolic inhibitor cycloheximide with and without colchicine to selectively inhibit eucaryotic metabolism was shown to severely affect procaryotic metabolism in sediment (and presumably particle and water) samples. Using fluorescently labelled bacteria as food, and under optimum conditions, up to 42% of the Protozoa population exhibited active grazing within 7 h. Using protozoan and bacterial community sizes and doubling times, it was calculated that each protozoan in Halifax Harbor would have to consume 13–118 bacteria per hour for the enumerated nanoplanktonic (<20 μm) Protozoa to be the sole control of the size of the bacterial community. Key words: marine, Protozoa, bacterivory, particles, bacteria.

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Role of NAD(P)H:quinone oxidoreductase (NQO1) in apoptosis induction by aziridinylbenzoquinones RH1 and MeDZQ.

Acta Biochimica Polonica ◽

10.18388/abp.2005_3411 ◽

2005 ◽

Vol 52 (4) ◽

pp. 937-942 ◽

Cited By ~ 4

Author(s):

Ausra Nemeikaite-Ceniene ◽

Aldona Dringeliene ◽

Jonas Sarlauskas ◽

Narimantas Cenas

Keyword(s):

Regression Analysis ◽

Redox Cycling ◽

Apoptosis Induction ◽

Electron Reduction ◽

Induced Apoptosis ◽

Phenylene Diamine

We aimed to characterize the role of NAD(P)H:quinone oxidoreductase (NQO1) in apoptosis induction by antitumour quinones RH1 (2,5-diaziridinyl-3-hydroxymethyl-6-methyl-1,4-benzoquinone) and MeDZQ (2,5-dimethyl-3,6-diaziridinyl-1,4-benzoquinone). Digitonin-permeabilized FLK cells catalyzed NADPH-dependent single- and two-electron reduction of RH1 and MeDZQ. At equitoxic concentrations, RH1 and MeDZQ induced apoptosis more efficiently than the nonalkylating duroquinone or H(2)O(2). The antioxidant N,N'-diphenyl-p-phenylene diamine, desferrioxamine, and the inhibitor of NQO1 dicumarol, protected against apoptosis induction by all compounds investigated, but to a different extent. The results of multiparameter regression analysis indicate that RH1 and MeDZQ most likely induce apoptosis via NQO1-linked formation of alkylating species but not via NQO1-linked redox cycling.

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The Legacy of the Idrija Mine Twenty-Five Years after Closing: Is Mercury in the Water Column of the Gulf of Trieste Still an Environmental Issue?

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph181910192 ◽

2021 ◽

Vol 18 (19) ◽

pp. 10192

Author(s):

Elena Pavoni ◽

Elisa Petranich ◽

Sergio Signore ◽

Giorgio Fontolan ◽

Stefano Covelli

Keyword(s):

Water Column ◽

Environmental Concern ◽

Anthropogenic Factors ◽

Northern Adriatic Sea ◽

Northern Adriatic ◽

High Discharge ◽

Fine Sediments ◽

Gulf Of Trieste ◽

Freshwater Inputs

Mercury (Hg) contamination in the Gulf of Trieste (northern Adriatic Sea) due to mining activity in Idrija (Slovenia) still represents an issue of environmental concern. The Isonzo/Soča River’s freshwater inputs have been identified as the main source of Hg into the Gulf, especially following periods of medium-high discharge. This research aims to evaluate the occurrence and distribution of dissolved (DHg) and particulate (PHg) Hg along the water column in the northernmost sector of the Gulf, a shallow and sheltered embayment suitable for the accumulation of fine sediments. Sediment and water samples were collected under unperturbed and perturbed environmental conditions induced by natural and anthropogenic factors. Mercury in the sediments (0.77–6.39 µg g−1) and its relationship to grain size were found to be consistent with previous research focused on the entire Gulf, testifying to the common origin of the sediment. Results showed a notable variability of DHg (<LOD–149 ng L−1) and PHg (0.39–12.5 ng L−1) depending on the interaction between riverine and marine hydrological conditions. Mercury was found to be mainly partitioned in the suspended particles, especially following periods of high discharge, thus confirming the crucial role of the river inputs in regulating PHg distribution in the Gulf.

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