摘要:

Photometric estimation of the activity of phosphoenolpyruvate carboxylase in maize leaves as depending on plant developmentIn order to measure photometrically the activity of Phosphoenolpyruvate carboxylase in homogenates of maize leaves, a method for larger test series was developed. When optimal conditions for the mixture, the pH‐value and the temperature of the test mixture had been developed, reliable values were measured.The activities of Phosphoenolpyruvate carboxylase are dependant on the age of maize leaves. The activities increased during the first ten days of leaf development. The following twenty days were marked by a relatively small reduction of the activity. Thereafter a steady decline of the activity took plac

ISSN:0044-3263    

DOI:10.1002/jpln.19771400502

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

Influence of N‐fertilization on the14C‐labelling of the ethanol soluble fraction and its components in spring wheat at different stages of developmentIn spring wheat plants from pot experiments the effect of different N‐fertilization on the14C‐labelling of the soluble fractions of amino acids, organic acids, and carbohydrates was studied.The fraction of14C‐labelled compounds, soluble in ethanol, was 50% at the start of the experiment, about 100% during flowering stage and 45% at the end of the experiment.At the end of the 24h14CO2‐assimilation period 90% of the activity in the plants were water soluble, carbohydrates containing 10 to 20 times higher14C‐activity than amino or organic acids.In plant labelled with14CO2during emergence of the ears, the solubility of14C‐labelled assimilates decreased till the ripening stage to 15% of the total14C‐activity, whereas the total activity itself decreased only to 50–80% during the same time.The higher N‐supply results in an enhanced decrease of soluble carbohydrates and in an increase of the soluble amino acid fraction. This leads also to an increased protein synthesis and14C‐assimilation into the protein of the kernels. The most important plant parts in respect to photosynthesis during the experiment period were upper leaves, upper stems and ears.The14C‐distribution throughout the plant is mainly determined by the time after14CO2‐treatment and less by the N‐fertilization. This points to similar pathways of14CO2‐assimilation in all trials.It is concluded, that the positive effect of the high N‐fertilization on the yield is due to the quick transformation of soluble assimilates into insoluble compounds, e.g. proteins and protein precursors. Increase of yield by high N‐fertilization is also due to a prolonged period of photosynthesis and therefore delayed ripening of th

ISSN:0044-3263    

DOI:10.1002/jpln.19771400503

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

Boron deficiency and Boron toxicity in Hibiscus esculentusThe development of symptoms in Okra under conditions of B‐deficiency and B‐toxicity was observed. It was compared if the symptoms correspond with the B‐contents and the growth of the plants.Symptoms of Boron deficiency in Okra are the same as in the other annual dicotyledons. The first visible microscopical symptom is a disturbance in the cambium region. Characteristic is an enlargement of the cambium. New divided cells do not differentiate. Visual symptoms are breaking of stems and petioles, thickening of these organs, cracking, dying of the tips and falling of buds. With a periodic supply of Boron correlations between Boron content and deficiency symptoms were not found.In the B‐toxicity range small yellow chlorosis developed on the margins of the older leaves. These symptoms are not to be used for diagnosis. Boron contents higher than 72 μg B/g DM gave a better measure for B‐toxicity. Growth and development of symptoms were in agreement with the high Boro

ISSN:0044-3263    

DOI:10.1002/jpln.19771400504

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

Effect of high phosphate fertilization on growth rate, zinc content and P/Zn ratio in grapevines (Vitis vinifera)In a 2 years' pot experiment with a soil low in available Zn, high doses of phosphate fertilizer induced Zn deficiency in grapevines (var. „Riesling”︁ on 5 C root stock). This negative effect of phosphate fertilization could almost be prevented by simultaneous application of Zn to the soil.The negative effect of high phosphate fertilization on the Zn status of the soil was well reflected in both the content of available Zn as well as in the diffusion rate of Zn (65Zn) in the soil.In young leaves of grapevines, Zn deficiency can be expected at Zn contents lower than 20 μg/g DM and P/Zn ratios larger than 170. These values, however, cannot be generalized as external factors modify them considerably. This latter holds true for the P/Zn ratio in particular.The most obvious Zn deficiency symptom was restricted elongation of the shoot due to shorter internodes. Typical for severe Zn deficiency were smaller leaves with intervenal chlorosis or even necrosis and the disappearance of the normally deeply lobed shape of the leaf blade. As a result of the growth inhibition of the shoot apex, growth of axillary buds had been enhanced and this led to a bushy shape of the Zn‐deficien

ISSN:0044-3263    

DOI:10.1002/jpln.19771400505

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

Extraction of free amino acids from fungal spores (Phycornyces blakesleeanus)Because extraction conditions are crucial for the reliability of biochemical analysis of fungal spore materia1, comparative investigations on methods were conducted, using the amount of free amino acids as a parameter of exhaustive extraction. It was found that optimal conditions are: Extraction in a Soxhlet apparatus with methanol as extracting medium (for 8 hours under reduced pressure and 40°C boiling temperature) or treatment with ice‐cold perchloric acid (10 % for 30 minutes) or trichloroacetic acid (10 % for 30 minutes). A pretreatment of the material by desintegration was not necessary. Extraction with hot water (70 or l00T) or with ethanol, propanol, butanol, 3,3 %perchloric or trichloroacetic acid proved to be inappropriate.All of the common amino acids were detected in the extracts except proline and phenylalanine. A few amino acids make up the majority of the pool (glutamic acid, glutamine, aspartic acid, asparagine, alanine and y‐butyric acid). These amino acids comprised about 80% of the total intracellular pool (ca. 12000 moles/l00mg spores) and account for nearly 2% of the spore dry weight. Sacrosine, probably being present in considerable amounts, could not be determined quantitati

ISSN:0044-3263    

DOI:10.1002/jpln.19771400506

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

Beitrag zum Studium der ZnCl+‐Adsorption durch BödenIn 3 carbonatfreien und 3 kalkhaltigen Bodenproben aus verschiedenen Bezirken Griechenlands und in einem Yolo‐Lehm aus Davis, Kalifornien wurde die Menge des adsorbierten Zinks bestimmt durch isotopische Verdünnung von mit65Zn‐markiertem ZnCl2und außerdem aus der Differenz zwischen Gesamt‐Zink und Gesamt‐Chlorid. Zusätzlich wurde die Menge des adsorbierten Chlorids durch isotopische Verdünnung von mit36Cl‐markiertem ZnCl2bestimmt. Man kann aus den Ergebnissen folgern, daß die Menge des Komplex‐Ions ZnCl+nicht bedeutsam ist. Die Ergebnisse zeigen, daß die beobachteten Diskrepanzen im Fall der kalkhaltigen Böden wahrscheinlich durch die Ausfällung oder Immobilisation des Zinks oder durch die Löslichkeit der Zn‐Fällungsprodukte in der Extrakti

ISSN:0044-3263    

DOI:10.1002/jpln.19771400507

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

Model experiments on the mechanism of bacterial iron‐reduction in water‐logged soilsIn model experiments, iron‐reduction with Bacillus polymyxa (nit+) and Clostridium butyricum (nit−) was followed in relation to the development of pH, Eh and glucose fermentation. In parallel tubes, the influence of NO, (KNO,) and/or Mn02‐Powder (Merck) on Fe(I1) formation and rH (calculated from pH and Eh) was measured. All tubes were incubated anaerobically (N2/C02 = 9/1) at 30°C. Both with Bacilluspolymyxa (nit+) as well as with Clostridium butyricum (nit−), the reduction‐intensity rH decreased rapidly reaching entirely reducing conditions (rH = 0) within 2–3 days. In both cases iron‐reduction and glucose utilization developed sigmoidal and miror symmetrically (Fig. 1)In the case of B. polymyxa (nit+) the addition of NO, and/or Mn02 suppressed iron‐reduction nearly entirely. With C. butyricum, only Mn02 (but not nitrate) affected iron‐reduction significantly. Nitrate remained unchanged throughout the incubation period, although completely reducing conditions (rH = 0) were obtained (Fig. 2).Apparently, nitrate, Mn02 or Fe203 are reduced directly and specifically rather than indirectly as a consequence of reducing metabolites and/or by a lowered redox potential in the environment. If nitrate, Mn02 and Fe203 are reduced chemically by reducing condition, the reduction sequence nitrate → Mn(1V)‐oxides → Fe(II1)‐oxides should occur in relation to pH and Eh (rH) and independently of the type of organism (nit+or nit−) in question. This view is rejected by the results presented.With nit+bacteria such as B. polymyxa, the enzyme nitrate reductase seems to act as one mechanism of iron‐ and manganese‐reduction. However, with C. butyricum (nit−), another, so far unknown enzym system (ferrireductase?), should be made respons

ISSN:0044-3263    

DOI:10.1002/jpln.19771400508

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

Fluorescence Spectroscopic Studies on Humic AcidsThe procedures of the fluorescence spectra of three humic acids have been investigated and compared. Differences were found in three points:1To get the maximum of fluorescence emission, different concentrations of the three humic acids were necessary.2The humic substances differed in pH‐dependence of the fluorescence.3With nearly equal wavelength of fluorescence emission, distinct deviations of the exciting wavelength were pointed out.The results show a connection between the conditions of the fluorescence and the contents of phenolic hydroxyl groups of the selected humic acids.The measurement of fluorescence is a relatively simple method for the characterization of humic acid

ISSN:0044-3263    

DOI:10.1002/jpln.19771400509

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

A procedure for interpolating the depth distribution of soil moisture tensionA programmable procedure is described to compute hydraulic gradients from soil moisture tensions non‐linearly distributed with depth.This interpolation‐technique is based upon a geometrical procedure. Compared with other curve smoothing techniques it is flexible with respect to the given data constellation and requires a relatively small computational effort.This method is compared with that of cubic spli

ISSN:0044-3263    

DOI:10.1002/jpln.19771400510

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

Der Einfluß des Molekulargewichtes auf die Adsorption von Dextranen an Natrium‐ und CalciummontmorillonitenSechs Glukosepolymere, deren Molekulargewicht von 10.300 bis 1.960.000 anstieg, wurden von Natrium‐ und Calciummontmorilloniten aus wäßrigen Lösungen adsorbiert. Bei 27°C folgten die Adsorptionsisothermen derLangmuir‐Gleichung. DieLangmuir‐Konstanten, a' (Adsorptionsmaximum) und, b' (Bindungsenergie) wurden berechnet. Ebenso wurden aus den Werten für dieLangmuir‐Konstante, a' die maximal von Dextranen bedeckte Oberf

ISSN:0044-3263    

DOI:10.1002/jpln.19771400511

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY