scholarly journals Influence of Iron on Respiration in Corn (Zea Mays) Seedlings

2011 ◽  
Vol 68 (1) ◽  
Author(s):  
Lucia MIHALESCU ◽  
Oana MARE ROSCA ◽  
Monica MARIAN ◽  
Zorica VOSGAN ◽  
Aurel MAXIM ◽  
...  
Keyword(s):  
Zea Mays ◽  
Respiratory Chain ◽  
Solution Concentration ◽  
Intensity Increase ◽  
Iron Ion ◽  
Respiration Intensity ◽  
Fecl3 Solution ◽  
Low Concentrations ◽  
Growing Environment

In this paper the influence of iron in different concentrations of FeCl3 solution on the respiration of corn (Zea mays) seedlings was observed. The following variants were used: V1 – as control, V2 = 0.1%FeCl3, V3 = 0.5%FeCl3, V4= 1%FeCl3. The respiration intensity of the 4 variants was determined applying the confined atmosphere procedure (Boysen-Jensen). This is a method based on determining the quantity of produced CO2. In case of this procedure, the contact between vegetal material and atmosphere takes place in a closed recipient, in which CO2 - resulted from respiration – is fixed by a solution of Ba(OH)2. An increase of the respiration intensity was noted, proportional with the increase of the administered FeCl3 solution concentration. Iron ion enters in the structure of cytochromes, which are components of the respiratory chain. Its presence in the growing environment of the corn seedlings led to the respiration increase. The intensity increase quickly evolves with low concentrations of iron, for example the variant with a concentration of 0.1% salt of FeCl3, for which it increased with 184% compared to the control, as the increase intensifies at concentrations of 0.5% with 259%. We note that in the last case, when iron is in the highest concentration of 1%FeCl3, the increase is no more so heightened, as it is higher with only 128% versus the previous variant. Iron highly stimulates the respiration up to a certain concentration, it was remarked

scholarly journals Inmobilización y retención nutrimental en aserrín de pino como sustrato agrícola.

2019 ◽  
Vol 37 (3) ◽  
pp. 261
Author(s):  
Joel Pineda Pineda ◽  
Felipe Sánchez del Castillo ◽  
Esaú Del Carmen Moreno Pérez ◽  
Luis Alonso Valdez Aguilar ◽  
Ana María Castillo González ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Solution Concentration ◽  
Particle Sizes ◽  
Similar Concentration ◽  
Volcanic Tuff ◽  
Pine Sawdust ◽  
Low Concentrations ◽  
Growing Medium ◽  
Leachate Water ◽  
Main Substrate

Pine (Pinus sp.) sawdust has been used as a growing medium for the cultivation of vegetables and ornamentals. In the present work the objective was to assess the immobilization or retention of N, P, K, and Ca in pine sawdust as the main substrate component by applying Steiner nutrient solution at different concentrations (20, 30 and 40 meq L-1). We used uncomposted sawdust, alone or in mixtures (70/30, v/v) with volcanic tuff of different particle sizes (fine ≤ 3 mm, medium 3-6 mm, and coarse 6-12 mm). For two months, leachate was collected daily, and every 10 days, the average concentrations of N, P, K, and Ca, as well as pH and electrical conductivity (EC) were measured. The effect of the interaction substrate × nutrient solution concentration on N, P, K and Ca in the leached water was observed. These nutrients increased in concentration in the leachate water in accord with the nutrient solution concentration and as the diameter of volcanic tuff particles diminished. Irrigation with 20 meq L-1 (2 dS m-1) concentration of nutrient solution reduced the concentration of N, P, K, and Ca in leached water below its concentration in the supplied nutrient solution, while irrigation with 30 or 40 meq L-1 (2 or 4 dS m-1) resulted in similar concentration in leached water up to 20 or 30 dat, but at 40 dat, concentration of these nutrients in the leached water was higher. Immobilization of N and P, K, and Ca retention in the sawdust substrate occurred during the first 40 ddt, related to an increase in pH (up to 8.6), a decrease in EC (until 0.5 dS m-1) and low concentrations of N, P, K, and Ca in the leached water.

The Donnan law and its application to ion exchanger polymers

1962 ◽  
Vol 268 (1334) ◽  
pp. 339-349 ◽  
Keyword(s):  
Distribution Coefficient ◽  
Single Phase ◽  
Solution Concentration ◽  
Ion Exchanger ◽  
Ion Concentration ◽  
Ion Distribution ◽  
Equilibrium Relation ◽  
Low Concentrations ◽  
Wide Range ◽  
A New Technique

A new technique of measuring the electrolyte up take from dilute solutions by ion exchanger polymers has been developed, which perm its measurements at solution concentrations as low as 10 -4 m. The results show that the Donnan equilibrium relation, which at low concentrations predicts a co-ion distribution coefficient proportional to the solution concentration, is not obeyed. In stead it is shown that the distribution coefficient is proportional over a very wide range to a low power of the external counter-ion concentration. Measurements of the diffusion coefficients in the exchanger phase show an abnormally high dependence on concentration. The conclusion is drawn that these phenomena are due to the fact that even the ‘homogeneous’ exchanger polymers are not uniform and thus cannot be treated as a single phase.

The effects of aluminum on Picearubens:factorial experiments using sand culture

1995 ◽  
Vol 25 (1) ◽  
pp. 8-17 ◽  
Author(s):  
Stephen J. McCanny ◽  
Martin J. Lechowicz ◽  
Bill Shipley ◽  
William H. Hendershot
Keyword(s):  
Gas Exchange ◽  
Fold Increase ◽  
Solution Concentration ◽  
Sand Culture ◽  
Experimental Conditions ◽  
Plant Weight ◽  
Positive Effects ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Low Concentrations

We used sand culture to examine the effects of aluminum (Al3+) on gas exchange and growth in 1+0 Picearubens Sarg. seedlings. Growth solutions were prepared to match the elemental concentrations of the soil solutions in a declining Abiesbalsamea (L.) Mill.–P. rubens stand. In our first experiment, we used a four-way factorial design to examine the interactions between Al, pH, nutrients, and CO2. All plants were nitrogen deficient. Photosynthetic rate and instantaneous water-use efficiency both declined at 250 μmol•L−1 Al, as did the root/shoot ratio of the seedlings. Plant weight, however, was not significantly affected by the 10-fold increase in Al solution concentration. These results were robust across a range of experimental conditions, suggesting that other aspects of soil acidification, such as NO3 fertilization in N deficient soils, could counteract the toxic effects of Al. In a second experiment, we examined the effects of subtoxic concentrations of Al at two levels of nutrient cation availability. Unlike in a previous study, cation fertilization affected neither gas exchange nor growth. While the decreases in root/shoot ratio and growth were expected at 250 μmol•L−1 Al, the peak in growth rates for intermediate concentrations of Al (25–100 μmol•L−1) was not. The latter result was interpreted in light of the positive effects that low concentrations of Al are known to have on other species.

Low Concentrations of Salicylic Acid Stimulate Insect Elicitor Responses in Zea mays Seedlings

2011 ◽  
Vol 37 (3) ◽  
pp. 263-266 ◽  
Author(s):  
Jurgen Engelberth ◽  
Sriram Viswanathan ◽  
Marie Jeanette Engelberth
Keyword(s):  
Zea Mays ◽  
Salicylic Acid ◽  
Low Concentrations

Reduced Transpiration and Increased Water Efficiency by Diuron in Corn (Zea mays)

Weed Science ◽  
1980 ◽  
Vol 28 (2) ◽  
pp. 180-185 ◽  
Author(s):  
Shabir Ahmed ◽  
R. A. Fletcher
Keyword(s):  
Zea Mays ◽  
Active Component ◽  
Dry Weight ◽  
Water Efficiency ◽  
Commercial Formulation ◽  
Leaf Stage ◽  
Stages Of Growth ◽  
Shoot Dry Weight ◽  
Low Concentrations ◽  
Corn Plants

Of several herbicides tested on both monocotyledon and dicotyledon species, diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] was found to be the most effective in reducing transpiration in corn (Zea maysL.) plants; a reduction of 40% occurred. It was established that diuron was the active component in reducing transpiration, and not the additives in the commercial formulation (Karmex) used in this study. Foliar applications of low concentrations (0.035 to 0.56 kg/ha) of diuron effectively reduced transpiration in both cultivars (Pioneer 3780A and Pride 1108) of corn plants, at all stages of growth tested (from 3- to 10-leaf stage). This effect of diuron on reduced transpiration occurred when the supply of water or nutrients to the corn plants was either limiting or non-limiting. The reduction of transpiration of corn plants after treatment also prevented the leaves from wilting and becoming senescent. This effect was persistent over 16 days. Diuron treatment increased the water efficiency of the plants and this effect was more pronounced when water was limiting. Compared to the control, the treated plants used up to 68% less water for each gram of shoot dry weight produced. The increase in water efficiency indicates that transpiration was reduced more than photosynthesis.

Mycotoxins and toxigenic fungi in insect-damaged maize harvested during 1983 in far North Queensland

1986 ◽  
Vol 37 (3) ◽  
pp. 235 ◽  
Author(s):  
BJ Blaney ◽  
MD Ramsey ◽  
AL Tyler
Keyword(s):  
Zea Mays ◽  
Fusarium Moniliforme ◽  
Early Stage ◽  
Insect Damage ◽  
Previous Survey ◽  
Toxigenic Fungi ◽  
Far North ◽  
Isolation Frequency ◽  
Trichoderma Sp ◽  
Low Concentrations

A survey for mycotoxins and toxigenic fungi in maize (Zea mays) grown during 1983 in Far North Queensland is reported. Zearalenone was detected in 148 of the 174 samples examined. Low concentrations of aflatoxins were detected in three of the samples. Ochratoxin A, sterigmatocystin, T-2 toxin and deoxynivalenol were not detected. The 1983 season was unusual in that plants were stressed from low rainfall in the early stage of growth. Insect damage, mainly by ear worms (Heliothis sp.), was severe. Despite this, there was no significant increase in zearalenone concentrations compared to a previous survey in 1982, when insect damage was minimal. Ten samples were used for fungal isolations. Fusarium moniliforme was the most frequently isolated fungus, and its isolation frequency increased in visibly damaged kernels. F. graminearum was most frequently isolated from kernels with a purple discoloration. The correlation between the isolation frequency of F. graminearum and zearalenone concentrations indicated that F. graminearum produced most of the zearalenone in the samples. Other fungi isolated included F. subglutinans, F. oxysporum, Aspergillus jlavus, A. niger, Penicillium sp., Trichoderma sp., Nigrospora sp., Curvularia sp., Drechslera sp., Acremonium zeae and Rhizoctonia sp.

scholarly journals Pivotal role of superoxides generated in the mitochondrial respiratory chain in peroxynitrite-dependent activation of phospholipase A2

2002 ◽  
Vol 366 (1) ◽  
pp. 307-314 ◽  
Author(s):  
Andrea GUIDARELLI ◽  
Orazio CANTONI
Keyword(s):  
Phospholipase A2 ◽  
Respiratory Chain ◽  
Mitochondrial Respiratory Chain ◽  
Complex Iii ◽  
Pivotal Role ◽  
Intact Cells ◽  
Calcium Dependent ◽  
Low Concentrations ◽  
Phospholipase A2 Inhibitors ◽  
Mitochondrial Respiratory

Exposure of PC12 cells to reagent peroxynitrite promotes the release of arachidonic acid (AA) mediated by activation of phospholipase A2 [Guidarelli, Palomba and Cantoni (2000) Br. J. Pharmacol. 129, 1539–1542]. We now present experimental evidence consistent with the notion that this response is not directly triggered by peroxynitrite but, rather, by reactive oxygen species generated at the level of complex III of the mitochondrial respiratory chain. In particular, superoxide (and not hydrogen peroxide) has a pivotal role in peroxynitrite-dependent activation of phospholipase A2. This observation was confirmed by results showing that superoxide, or peroxynitrite, promotes release of AA in isolated mitochondria. Consistently, the release of AA elicited by either peroxynitrite or A23187 in intact cells was shown to be calcium-dependent and differentially affected by phospholipase A2 inhibitors with different levels of specificity. In particular, the effects of peroxynitrite, unlike those of A23187, were both sensitive to low concentrations of two general phospholipase A2 inhibitors and insensitive to arachidonyltrifluoromethyl ketone, which shows some selectivity towards cytosolic phospholipase A2. In addition, peroxynitrite and A23187 synergistically enhanced the release of AA. Collectively, the above results demonstrate that peroxynitrite causes inhibition of complex III, followed by enforced formation of superoxides that stimulate the activity of a calcium-dependent PLA2 isoform, probably localized in the mitochondria.

scholarly journals The effect of respiratory chain impairment of β-oxidation in rat heart mitochondria

1996 ◽  
Vol 319 (2) ◽  
pp. 633-640 ◽  
Author(s):  
Simon EATON ◽  
Morteza POURFARZAM ◽  
Kim BARTLETT
Keyword(s):  
Respiratory Chain ◽  
Rat Heart ◽  
Redox State ◽  
Complex Iii ◽  
Heart Mitochondria ◽  
Cardiac Ischaemia ◽  
Low Concentrations ◽  
Rat Heart Mitochondria ◽  
Hydroxyacyl Coa Dehydrogenase ◽  
14Co2 Release

Cardiac ischaemia leads to an inhibition of β-oxidation flux and an accumulation of acyl-CoA and acyl-carnitine esters in the myocardium. However, there remains some uncertainty as to which esters accumulate during cardiac ischaemia and therefore the site of inhibition of β-oxidation [Moore, Radloff, Hull and Sweely (1980) Am. J. Physiol. 239, H257-H265; Latipää (1989) J. Mol. Cell. Cardiol. 21, 765–771]. When β-oxidation of hexadecanoyl-CoA in state III rat heart mitochondria was inhibited by titration of complex III activity, flux measured as 14CO2 release, acid-soluble radioactivity or as acetyl-carnitine was progressively decreased. Low concentrations of myxothiazol caused reduction of the ubiquinone pool whereas the NAD+/NADH redox state was less responsive. Measurement of the CoA and carnitine esters generated under these conditions showed that there was a progressive decrease in the amounts of chain-shortened saturated acyl esters with increasing amounts of myxothiazol. The concentrations of 3-hydroxyacyl and 2-enoyl esters, however, were increased between 0 and 0.2 µM myxothiazol but were lowered at higher myxothiazol concentrations. More hexadecanoyl-CoA and hexadecanoyl-carnitine were present with increasing concentrations of myxothiazol. We conclude that 3-hydroxyacyl-CoA dehydrogenase and acyl-CoA dehydrogenase activities are inhibited by reduction of the ubiquinone pool, and that this explains the confusion over which esters of CoA and carnitine accumulate during cardiac ischaemia. Furthermore these studies demonstrate that the site of the control exerted by the respiratory chain over β-oxidation is shifted depending on the extent of the inhibition of the respiratory chain.

scholarly journals Effect of Sweet Marjoram (Origanum majorana L.) Cogermination and Aqueous Extracts on Maize (Zea mays L.)

2018 ◽  
Vol 1 (1) ◽  
pp. 11-16
Author(s):  
Dorina Bonea ◽  
Viorica Urechean
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Petri Dish ◽  
Allelopathic Effect ◽  
Initial Growth ◽  
Aqueous Extracts ◽  
Maize Seedlings ◽  
Maize Seeds ◽  
Low Concentrations ◽  
Origanum Majorana

Abstract The purpose of this study was to examine the allelopathic effect of sweet marjoram (O. majorana) on the germination and early stages of maize seedlings. Two experiments were performed under laboratory conditions (in Petri dishes). In the first experience, Origanum majorana seeds were cogerminated with maize (Zea mays) seeds in the same Petri dish. For the second experience were used aqueous extracts from fresh and dry aboveground biomass of the sweet marjoram (stem, leaves) in concentrations of 1%, 2% and 3%. Cogermination of O. majorana with maize seeds has significantly stimulated the germination index (Gi) and growth of maize seedlings. Aqueous extracts of sweet marjoram in a concentration of 1% and 2% have significantly stimulated shoot length of maize. On the other hand, aqueous extracts at a concentration of 3% significantly inhibited root length of maize. These results suggest that the cogermination with sweet marjoram seeds may be an alternative to biostimulation of maize initial growth, and aqueous extracts in low concentrations could be used as growth bioregulators.

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