A slime mould pigment as indicator of acidity

Seifriz, William; Zetzmann, Marie

doi:10.1007/bf01603385

Cited by 29 publications

(12 citation statements)

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“…Such results lead to the suggestion, already advanced by Cayley (1929) and Seifriz and Russell (1936), that there is a definite rhythmical fruiting exhibited by myxomycetes. Cayley found that Didymium difforme possesses a much shorter vegetative phase than either D. rigripes or D. squamulosum but stated that the factors causing plasmodia to form fruiting bodies are " still a complete mystery " (p. 234).…”

Section: The Effect Of Light On the Fruiting Of Myxomycetes'supporting

confidence: 54%

“…This figure shows that the vegetative phase of P. tenerum varied from 2 to 6 days in natural light and well illustrates the necessity for more controlled conditions than are normally found in the laboratory. Seifriz and Russell (1936) apparently encountered similar difficulties, since they found that under laboratory conditions the rhythm of P. polycephalum varied from 9 to 23 days -a situation non-existent for this species (polycephalum) under conditions of constant light, temperature, and food supply. Under such controlled conditions some variation did occur in cultures of P. tenerum, but this variation was not nearly so great as that exhibited by cultures grown in natural light.…”

Section: The Effect Of Light On the Fruiting Of Myxomycetes'mentioning

confidence: 91%

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The Effect of Light on the Fruiting of Myxomycetes

Gray

1938

American Journal of Botany

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Section: The Effect Of Light On the Fruiting Of Myxomycetes'supporting

confidence: 54%

Section: The Effect Of Light On the Fruiting Of Myxomycetes'mentioning

confidence: 91%

The Effect of Light on the Fruiting of Myxomycetes

Gray

1938

American Journal of Botany

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“…Perhaps the most significant result of these findings is the fact that it makes easily available different strains of an organism which lends itself easily to physiologjcal and physico-chemical investigations on practically pure protoplasm as is evidenced by the work of Seifriz (1936), Luyet and Gehenio (]91<2), 1\100re (1935), Brooks (1!J25) and others. Careful investigation of different strains of this organism may yield information of fundamental importance for the explanation of slight differences between closely-related protoplasms.…”

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confidence: 99%

The Existence of Physiological Strains in Physarum Polycephalum

Gray¹

1945

American Journal of Botany

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BRANDZA (1927), working with myxomycete plasmodia which he had collected from their natural habitats, observed that frequently when two plasmodia of the same species were placed in close proximity, they would not fuse but withdrew from the vicinity of each other and formed their fruiting structures separately. This separation occurred particularly when the plasmodia were of slightly different color and seemed to bear out Brandzu's statement that several of the species with which he worked were each composed of different physiological strains as evidenced by their inability to fuse. Hrandza's statement may be criticized, however, on the grounds that while he attempted to apply Torrend's (1907) species criterion, he had not met all of the requirements set forth by Torrend, who specifically states that the plasmodia should he grown under the same environmental conditions. One might suppose that it was quite obvious that in some of the species he mentioned, Brandza was dealing with different strains because the plasmodia were different in color; however, his own earlier work (Brandza, 1926) and the work of Kambly (1939) would cast some doubt on the advisability of employing plasmodial color either as a taxonomic character or as a factor in the delimitation of strains or races. The fact that Brandza observed that plasmodia of the same species which were slightly differently colored would frequently not fuse does not necessarily mean that the two plasmodia represented different strains but may mean that the plasmodia were in different physiological states at the time they were placed together. This is particularly plausible in dew of the work of Seifriz and Zetzmann (1935) who demonstrated that a natural pH indicator exists in the plasmodium of Ph,ysarum polycephalum Sehw., and showed that in the course of its development, the plasmodium of this species may change color several times.Skupienski (19M), investigating temperature relations of Didymium xanthopus (Ditm.) Fr., found that the typical form of this species would not produce plasmodia and fruiting bodies above 25 0 C. whereas another form of the same species would produce plasmodia and fruiting bodies at temperatures as high as 30 0 C. ; Skupienski assigned the race name "thermophilum" to the form which was able to grow at the higher temperatures.On the basis of the work of Skupienski and Brandza it seems possible that physiological strains do 1 Moore, who kindly supplied him with thcir cultures of l'hysflrwm ]Jolyce]Jhlllum. Thanks are also due Dr. Martin for his helpful criticisms of the manuscript. exist in some species of myxomycetes; however, the work of Winer and Moore (1941) would tend to raise further doubt as to whether Brandza was actually working with distinct strains. These investigators, working with Physarum polycephalum Schw., found that when two sub-cultures from the same plasmodium were placed on different media (oatmeal agar and rice agar), after three weeks bits of plasmodia from the two different cultures would not fuse. They suggest that...

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“…However, there are disadvantages: (1) the plasmodium is injured in making transfers; (2) it is very difficult to obtain successive transplants of equal size; and (3) there is considerable physiological variation depending upon age of culture (Seifriz and Zetzmann, 1935;Lewis, 1942) and upon nutrition (Cohen, 1939;Winer and Moore, 1941). Physiological variations were kept at a minimum by standardizing the technique of culturing and handling the mold.…”

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Galvanotaxis of Slime Mold

Anderson

1951

Journal of General Physiology

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The plasmodium of Physarum polycephalum reacts to direct current by migration toward the cathode. Cathodal migration was obtained upon a variety of substrata such as baked clay, paper, cellophane, and agar with a current density in the substratum of 1.0 µa./mm.2 Injury was produced by current densities of 8.0 to 12.0 µa./mm.2 The negative galvanotactic response was not due to electrode products. Attempts to demonstrate that the response was due to gradients or orientation in the substratum, pH changes in the mold, cataphoresis, electroosmosis, or endosmosis were not successful. The addition of salts (CaCl2, LiCl, NaCl, Na2SO4, NaHCO3, KCl, MgSO4, sodium citrate, and sea water) to agar indicated that change of cations had more effect than anions upon galvanotaxis and that the effect was upon threshold values. K ion (0.01 M KCl) increased the lower threshold value to 8.0 µa./mm.2 and the upper threshold value to 32.0 µa./mm.2, whereas the Li ion (0.01 M LiCl) increased the lower threshold to only 4.0 µa./mm.2 and the upper threshold to only 16.0 µa./mm.2 The passage of electric current produced no increase in the rate of cathodal migration; neither was there a decrease until injurious current densities were reached. With increase of subthreshold current densities there was a progressive decrease in rate of migration toward the anode until complete anodal inhibition occurred. There was orientation at right angles to the electrodes in alternating current (60 cycle) with current density of 4.0 µa./mm.2 and in direct current of 5.0 µa./mm.2 when polarity of current was reversed every minute. It is concluded that the negative galvanotactic response of P. polycephalum is due to inhibition of migration on the anodal side of the plasmodium and that this inhibition results in the limitation of the normal migration of the mold to a cathodal direction. The mechanism of the anodal inhibition has not been elucidated.

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A slime mould pigment as indicator of acidity

Cited by 29 publications

References 9 publications

The Effect of Light on the Fruiting of Myxomycetes

The Effect of Light on the Fruiting of Myxomycetes

The Existence of Physiological Strains in Physarum Polycephalum

Galvanotaxis of Slime Mold

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