Soil solution composition in association with the toxicity of banded di-ammonium phosphate to wheat and amelioration by CaCO3

2003 ◽  
Vol 54 (2) ◽  
pp. 183 ◽  
Author(s):  
X. K. Zhang ◽  
Z. Rengel
Keyword(s):  
Soil Solution ◽  
Ammonium Phosphate ◽  
Growth Period ◽  
Ammonia Toxicity ◽  
High Concentration ◽  
P Concentration ◽  
Soil Liming ◽  
Rooting Density ◽  
Hydrolysis Of ◽  
Limed Soil

Our previous publications showed that gradients of pH, electrical conductivity, ammonium, phosphorus, and calcium were formed between di-ammonium or mono-ammonium phosphate bands and roots. These gradients shifted and diminished with time. Roots suffered from ammonia toxicity near the band, but soil liming before banding ameliorated the toxicity. In the present study, DAP was banded 1 cm away from wheat (Triticum aestivum) seeds sown in slightly acidic sandy Lancelin soil that was either limed (CaCO3) or not. After 35 days, the pH and concentration of 9 ions were measured in soil solution extracted from soil obtained at different distances between the fertiliser band and seed.Toxicity symptoms were noted on 7-day-old plants grown in the non-limed treatment; in contrast, plants grown in the CaCO3 treatment did not show these symptoms during the whole growth period. In comparison with the non-limed treatment, CaCO3 addition markedly lowered the ammonium and P concentration in soil solution extracted from soil between the fertiliser band and the seed. Although a lower Ca concentration was measured in the vicinity of the DAP band in the non-limed than in the limed treatment, Ca in non-limed soil was still sufficiently high to prevent deficiency in plants, implying that there might be no ground for the association of an injurious effect of DAP and Ca deficiency as suggested in other studies. Around 2.8 mg Al/L soil solution was detected in the non-limed treatment, but liming with CaCO3 reduced Al concentration in all soil sections, especially those with the high rooting density. Therefore, a possibility that Al toxicity was related to the DAP toxicity in non-limed soils cannot be excluded, considering that even higher Al would have existed in the soil solution in the vicinity of the fertiliser band during the first couple of days. In conclusion, the causal factors associated with DAP toxicity might be high concentration of ammonium and free ammonia resulting from hydrolysis of DAP, and high P and possibly high Al concentrations.

Role of soil pH, Ca supply, and banded P fertilisers in modulating ammonia toxicity to wheat

2000 ◽  
Vol 51 (6) ◽  
pp. 691 ◽  
Author(s):  
Xike Zhang ◽  
Zdenko Rengel
Keyword(s):  
Soil Ph ◽  
Ammonium Phosphate ◽  
Ammonia Toxicity ◽  
Ammonium Concentration ◽  
High Concentration ◽  
Wheat Growth ◽  
Treated Soil ◽  
Early Seedling ◽  
And Control

Di-ammonium phosphate (DAP) and mono-ammonium phosphate (MAP) banded close to seed may cause ammonia (NH 3 ) toxicity by inhibiting seed germination and early seedling growth. A pH increase around the fertiliser band and/or limited Ca supply may exaggerate ammonia toxicity. In the current study, wheat growth and gradients of pH, electrical conductivity (EC), ammonium (NH 4 + ), and P concentration in soil were studied by comparing banded DAP + urea or MAP + urea fertilisers in control or gypsum- or CaCO 3 -treated Lancelin soil. After 21 days of wheat growth, visual symptoms of ammonia toxicity appeared in the gypsum-treated and control plants, but not in the CaCO 3 -treated plants. The symptoms were more severe in the MAP treatments than in DAP treatments. An addition of CaCO 3 increased soil pH CaCl2 from 5.1 to 7.3, and the ammonium concentration was lower than that in the gypsum-treated and control soils. In the gypsum-treated and control soils, pH increased by nearly 1 unit in the vicinity of the DAP or MAP band. In contrast, soil pH decreased in the location of the DAP or MAP band in the CaCO 3 -treated soil. Banding of MAP or DAP in the gypsum-treated soil caused an increase in soil EC. The good plant growth on the soil amended with CaCO 3 might have been related to the low ammonium concentration in the soil and the high concentration of Ca. Gypsum and CaCO3 decreased the availability of P supplied in the MAP or DAP band. It was concluded that increased pH and higher Ca content in sandy soil may alleviate ammonia toxicity to wheat.

THE HYDROLYSIS OF MONOPHOSPHOINOSITIDE BY EXTRACTS OF BRAIN

1967 ◽  
Vol 45 (6) ◽  
pp. 853-861 ◽  
Author(s):  
W. Thompson
Keyword(s):  
Fatty Acids ◽  
Enzyme Activity ◽  
Calcium Ions ◽  
Brain Extract ◽  
Monovalent Cations ◽  
High Concentration ◽  
Diffusible Factor ◽  
Hydrolysis Of ◽  
The Brain ◽  
Long Chain

The hydrolysis of monophosphoinositide by soluble extracts from rat brain is described. Diglyceride and inositol monophosphate are liberated along with a small amount of free fatty acids. Hydrolysis of the lipid is optimal at pH 5.4 in acetate buffer. The reaction is stimulated by calcium ions or by high concentration of monovalent cations and, to a less extent, by long-chain cationic amphipathic compounds. Enzyme activity is lost on dialysis of the brain extract and can be restored by diffusible factor(s). Some differences in the conditions for hydrolysis of mono- and tri-phosphoinositides are noted.

Chemistry of oxylipin pathways in marine diatoms

2007 ◽  
Vol 79 (4) ◽  
pp. 481-490 ◽  
Author(s):  
Angelo Fontana ◽  
Giuliana d'Ippolito ◽  
Adele Cutignano ◽  
Antonio Miralto ◽  
Adrianna Ianora ◽  
...  
Keyword(s):  
Higher Plants ◽  
Larval Growth ◽  
Marine Macroalgae ◽  
High Concentration ◽  
Marine Diatoms ◽  
Fatty Acid Derivatives ◽  
The Family ◽  
Hydrolysis Of ◽  
Catalyzed Oxidation

Oxylipins are important signal transduction molecules widely distributed in animals and plants where they regulate a variety of events associated with physiological and pathological processes. The family embraces several different metabolites that share a common origin from the oxygenase-catalyzed oxidation of polyunsaturated fatty acids. The biological role of these compounds has been especially studied in mammalians and higher plants, although a varied and very high concentration of these products has also been reported from marine macroalgae. This article gives a summary of our results concerning the oxylipin chemistry of marine diatoms, a major class of planktonic microalgae that discourage predation from their natural grazers, zooplanktonic copepods, using chemical warfare. These apparently harmless microscopic cells produce a plethora of oxylipins, including short-chain unsaturated aldehydes, hydroxyl-, keto-, and epoxyhydroxy fatty acid derivatives, that induce reproductive failure in copepods through abortions, congenital malformations, and reduced larval growth. The biochemical process involved in the production of these compounds shows a simple regulation based on decompartmentation and mixing of preexisting enzymes and requires hydrolysis of chloroplast-derived glycolipids to feed the downstream activities of C16 and C20 lipoxygenases.

Gradients of pH, ammonium, and phosphorus between the fertiliser band and wheat roots

1999 ◽  
Vol 50 (3) ◽  
pp. 365 ◽  
Author(s):  
Xike Zhang ◽  
Zdenko Rengel
Keyword(s):  
Ammonium Phosphate ◽  
Dry Weight ◽  
Plant Roots ◽  
Ammonia Toxicity ◽  
Phosphorus Concentration ◽  
Wheat Roots ◽  
Shoot Dry Weight ◽  
Nylon Mesh ◽  
Extractable P ◽  
Fertiliser Use

Di-ammonium phosphate (DAP) band application generally improves phosphorus (P) fertiliser use efficiency but can cause ammonia toxicity to plants. We used specially constructed pots to study P and ammonium (NH4+) gradients between the DAP band and plant roots grown in 2 soils. The pots were with or without a 30-mm nylon mesh between the roots and the fertiliser band, and had a movable side to enable sampling of soil layers at various distances from the fertiliser band and/or plant roots. After 28 days, ammonia toxicity symptoms occurred in plants grown in Lancelin soil in both mesh and no-mesh pots with the band placed 1 cm from the seed. Smaller root and shoot dry weights and a shorter root length were measured in both soils in no-mesh pots when the banding distance from the seed was 1 cm compared with 2.5 cm. In contrast, no differences in root and shoot dry weight occurred when direct contact between the roots and the fertiliser band was prevented in mesh pots; however, roots were shorter in mesh pots when fertiliser was banded 1 cm, compared with 2.5 cm, from the seed. The highest values for pH, NH4+ concentration, and bicarbonate-extractable P level occurred 4–5 cm from the seed in mesh pots, and in the layer between the fertiliser band and the seed in no-mesh pots. Phosphorus concentration in shoots was greater when plants were grown in Lancelin than in New Norcia soil, and when grown in no-mesh compared with mesh pots. In conclusion, large gradients of pH, ammonium, and bicarbonate-extractable P existed around plant roots when DAP and ammonium sulfate were banded in the vicinity of the seed. The frequently employed practice of growing plants in mesh pots to characterise nutrient gradients in soil close to roots, including the rhizosphere soil, results in plants with altered growth and nutrient accumulation characteristics in comparison to plants with no physical restriction for root growth within the pot.

Heat pretreatment improves the enzymatic hydrolysis of granular corn starch at high concentration

2018 ◽  
Vol 64 ◽  
pp. 193-199 ◽  
Author(s):  
Haocun Kong ◽  
Xue Yang ◽  
Zhengbiao Gu ◽  
Zhaofeng Li ◽  
Li Cheng ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Corn Starch ◽  
High Concentration ◽  
Heat Pretreatment ◽  
Hydrolysis Of

scholarly journals Catalysis of Rice Straw Hydrolysis by the Combination of Immobilized Cellulase fromAspergillus nigeronβ-Cyclodextrin-Fe3O4Nanoparticles and Ionic Liquid

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Po-Jung Huang ◽  
Ken-Lin Chang ◽  
Jung-Feng Hsieh ◽  
Shui-Tein Chen
Keyword(s):  
Ionic Liquid ◽  
Rice Straw ◽  
Reaction Rate ◽  
Magnetic Particles ◽  
Initial Reaction Rate ◽  
Initial Reaction ◽  
High Concentration ◽  
Solid Reaction ◽  
Immobilized Cellulase ◽  
Hydrolysis Of

Cellulase fromAspergillus nigerwas immobilized ontoβ-cyclodextrin-conjugated magnetic particles by silanization and reductive amidation. The immobilized cellulase gained supermagnetism due to the magnetic nanoparticles. Ninety percent of cellulase was immobilized, but the activity of immobilized cellulase decreased by 10%. In this study, ionic liquid (1-butyl-3-methylimidazolium chloride) was introduced into the hydrolytic process because the original reaction was a solid-solid reaction. The activity of immobilized cellulase was improved from 54.87 to 59.11 U g immobilized cellulase−1at an ionic liquid concentration of 200 mM. Using immobilized cellulase and ionic liquid in the hydrolysis of rice straw, the initial reaction rate was increased from 1.629 to 2.739 g h−1 L−1. One of the advantages of immobilized cellulase is high reusability—it was usable for a total of 16 times in this study. Compared with free cellulase, magnetized cellulase can be recycled by magnetic field and the activity of immobilized cellulase was shown to remain at 85% of free cellulase without denaturation under a high concentration of glucose (15 g L−1). Therefore, immobilized cellulase can hydrolyze rice straw continuously compared with free cellulase. The amount of harvested glucose can be up to twentyfold higher than that from the hydrolysis by free cellulase.

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