Monitoring and pH regulation in urban hydroponic systems

2-[N-morpholino] ethanesulfonic acid (MES) buffer or Amberlite DP-1 (cation-exchange resin beads) were used to stabilize substrate pH of passive-wicking, solid-matrix hydroponic systems in which small canopies of Brassica napus L. (CrGC 5-2, genome: ACaacc) were grown to maturity. Two concentrations of MES (5 or 10 m m) were included in Hoagland 1 nutrient solution. Alternatively, resin beads were incorporated into the 2 vermiculite: 1 perlite (v/v) growth medium at 6% or 12% of total substrate volume. Both strategies stabilized pH without toxic side effects on plants. Average seed yield rates for all four pH stabilization treatments (13.3 to 16.9 g·m-2·day-1) were about double that of the control (8.2 g·m-2·day-1), for which there was no attempt to buffer substrate pH. Both the highest canopy seed yield rate (16.9 g·m-2·day-1) and the highest shoot harvest index (19.5%) occurred with the 6% resin bead treatment, even though the 10 mm MES and 12% bead treatments maintained pH within the narrowest limits. The pH stabilization methods tested did not significantly affect seed oil and protein contents.

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APPLICATION ONE OF HYDROPONIC SYSTEMS IN PRODUCTION OF Catharanthus roseus L. PLANT

Journal of Plant Production ◽

10.21608/jpp.2009.118637 ◽

2009 ◽

Vol 34 (6) ◽

pp. 6595-6615

Author(s):

E. Koriesh ◽

A. Khalil ◽

Y. Abd El-Fatah

Keyword(s):

Catharanthus Roseus ◽

Hydroponic Systems

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CPX, a selective A1-adenosine-receptor antagonist, regulates intracellular pH in cystic fibrosis cells

AJP Cell Physiology ◽

10.1152/ajpcell.1995.269.1.c226 ◽

1995 ◽

Vol 269 (1) ◽

pp. C226-C233 ◽

Cited By ~ 29

Author(s):

V. Casavola ◽

R. J. Turner ◽

C. Guay-Broder ◽

K. A. Jacobson ◽

O. Eidelman ◽

...

Keyword(s):

Cystic Fibrosis ◽

Receptor Antagonist ◽

Intracellular Ph ◽

Adenosine Receptor ◽

Ph Regulation ◽

Cystic Fibrosis Transmembrane Regulator ◽

Wild Type ◽

A1 Adenosine Receptor ◽

Adenosine Receptor Antagonist ◽

Cystic Fibrosis Transmembrane

The selective A1-adenosine-receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine (CPX), has been reported to activate Cl- efflux from cystic fibrosis cells, such as pancreatic CFPAC-1 and lung IB3 cells bearing the cystic fibrosis transmembrane regulator(delta F508) mutation, but has little effect on the same process in cells repaired by transfection with wild-type cystic fibrosis transmembrane regulator (O. Eidelman, C. Guay-Broder, P. J. M. van Galen, K. A. Jacobson, C. Fox, R. J. Turner, Z. I. Cabantchik, and H. B. Pollard. Proc. Natl. Acad. Sci. USA 89: 5562-5566, 1992). We report here that CPX downregulates Na+/H+ exchange activity in CFPAC-1 cells but has a much smaller effect on cells repaired with the wild-type gene. CPX also mildly decreases resting intracellular pH. In CFPAC-1 cells, this downregulation is dependent on the presence of adenosine, since pretreatment of the cells with adenosine deaminase blocks the CPX effect. We also show that, by contrast, CPX action on these cells does not lead to alterations in intracellular free Ca2+ concentration. We conclude that CPX affects pH regulation in CFPAC-1 cells, probably by antagonizing the tonic action of endogenous adenosine.

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Cytoplasmic pH regulation in phorbol ester-activated human neutrophils

AJP Cell Physiology ◽

10.1152/ajpcell.1986.251.1.c55 ◽

1986 ◽

Vol 251 (1) ◽

pp. C55-C65 ◽

Cited By ~ 88

Author(s):

S. Grinstein ◽

W. Furuya

Keyword(s):

Metabolic Pathways ◽

Phorbol Esters ◽

Ph Regulation ◽

Human Neutrophils ◽

Hexose Monophosphate ◽

Cytoplasmic Ph ◽

Extracellular Acidification ◽

Hexose Monophosphate Shunt ◽

Activated Neutrophils ◽

Cytoplasmic Acidification

Activation of neutrophils by 12-O-tetradecanoylphorbol-13-acetate (TPA) is accompanied by an initial cytoplasmic acidification, followed by an alkalinizing phase due to Na+-H+ countertransport. The source of the acidification, which is fully expressed by activation with TPA in Na+-free or amiloride-containing media, was investigated. The acidification phase was detected also in degranulated and enucleated cytoplasts, ruling out a major contribution by the nucleus or secretory vesicles. Cytoplasmic acidification was found to be associated with an extracellular acidification, suggesting metabolic generation of H+. Two principal metabolic pathways are stimulated in activated neutrophils: the reduction of O2 by NADPH-oxidase and the hexose monophosphate shunt. A good correlation was found between the activity of these pathways and the changes in cytoplasmic pH. Inhibition of superoxide synthesis prevented the TPA-induced cytoplasmic acidification. Moreover, activation of the hexose monophosphate shunt with permeable NADPH-oxidizing agents (in the absence of TPA) also produced a cytoplasmic acidification. Cytoplasmic acidification was also elicited by exogenous diacylglycerol and by other beta-phorbol diesters, which are activators of the kinase, but not by unesterified phorbol or by alpha-phorbol diesters, which are biologically inactive. The results suggest that the cytoplasmic acidification induced by phorbol esters in neutrophils reflects accumulation of H+ liberated during the metabolic burst that follows activation.

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Effects of Plant Age and Root Damage on Internalization of Shiga Toxin-Producing Escherichia coli in Leafy Vegetables and Herbs

Horticulturae ◽

10.3390/horticulturae7040068 ◽

2021 ◽

Vol 7 (4) ◽

pp. 68

Author(s):

Yi-Ju Wang ◽

Amanda J. Deering ◽

Hye-Ji Kim

Keyword(s):

Escherichia Coli ◽

Plant Species ◽

Shiga Toxin ◽

Production Systems ◽

Plant Age ◽

Leafy Vegetables ◽

Root Damage ◽

Hygiene Practices ◽

Hydroponic Systems ◽

Stx1 Gene

Our previous study reported that fresh produce grown in aquaponic and hydroponic systems can pose potential food safety hazards due to an accidental introduction of contaminated fish and cross-contamination between the systems. In this study, we examined the effects of plant species and age on the likelihood and level of internalization of Shiga toxin-producing Escherichia coli (STEC) in aquaponic and hydroponic systems. Four plant species, basil (Ocimum basilicum L. cv. Genovese), cilantro (Coriandrum Sativum L.), lettuce (Lactuca sativa cv. Cherokee), and kale (Brassica oleracea var. sabellica), received root damage treatment as seedlings before transplanting or mature plants at three weeks after transplanting by cutting off 1-cm tips of one-third of the roots. Enrichments and selective media were used for the isolation, and presumptive positive colonies were confirmed by PCR for the presence of stx1 gene in plant tissues, recirculating water, and fish feces collected at four weeks after transplanting. In hydroponic systems, STEC was found neither in the solution nor in the roots and leaves of all four plant species, possibly through improved sanitation and hygiene practices. However, consistent with our previous findings, STEC was found in the water, on the plant roots, and in the fish feces in aquaponic systems, even after thorough sanitation prior to the study. Regardless of plant age, STEC was internalized in the roots of all plant species when the roots were damaged, but there was no difference in the degree of internalization with STEC among plant species. STEC was present in the leaves only when seedlings received root damage treatment and were grown to maturity, indicating that root damage allows STEC to internalize in the roots within a week, but a longer period is required for STEC to internalize into the leaves. We concluded that root damage on seedlings can cause the internalization of E. coli O157:H7 in the edible parts of leafy vegetables and herbs in soilless production systems.

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