Respiration of Protoplasts Isolated from Aspergillus Nidulans

Isaac, Susan; Gokhale, Ashok V.

doi:10.1007/978-3-0348-6556-2_147

Cited by 2 publications

(3 citation statements)

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“…Early protoplasts originate from apical cytoplasm and the protoplasts released later represent subapical and distal cytoplasm (Isaac et al, 1978;Isaac & Gokhale, 1983 ;Gaugy & Fivre, 1982). Thus, our results demonstrate that (1 + 3)-fl-and (1 +4)fl-glucan synthases have a different subcellular localization along the hyphae.…”

Section: Discussionmentioning

confidence: 99%

Distribution of (l->3)- - and (l->4)- -Glucan Synthases Along the Hyphae of Saprolegnia monoica

Girard

Fèvre

1984

Microbiology

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Protoplasts from hyphae of Saprolegnia monoica, collected from lytic medium after different times of incubation, represented a sequential fractionation of mycelium from apical to distal zones. This method gives the opportunity to study the intrahyphal localization of cell wall glucan synthases in relation to apical growth. (1 +4)-P-Glucan synthases were mainly found in early protoplasts (i.e. from apical zones) while the highest (1 +3)+glucan synthase activities were recovered in late protoplasts (i.e. from the subapical zones). Early protoplasts also exhibited the highest rate of cell wall synthesis during regeneration. The distribution of the enzymes along the fungal hyphae might provide a clue to the mechanisms of cell wall polysaccharide deposition during apical growth. METHODS Culture methods. Saprolegnia monoicaPringsheim (no. 539 67 Dick) obtained from CBS, Baarn, The Netherlands, was maintained on a wheat flour medium. Mycelia were grown in liquid medium (Machlis, 1953) at 23 "C for 48 h and harvested by filtration. Protopfast production. Mycelia (48 h old) were converted to protoplasts during incubation in a lytic medium pH 5.8, containing 5 mg Driselase ml-1 (Fluka, Buchs, Switzerland), 1 mg cellulase ml-1 and 0.5 M-sorbitol as 0022-1287/84/0001-1635 $02.00 0 1984 SGM Journal of Botany 40, 449-460. RAYMOND, Y., FICHER, G. B. & MACLACHLAN, G. A. (1978). Tissue slice and particulate p glucan synthetase activities from Pisum epicotyls. Plant Physiology 61, 938-942. SIETSMA, J. H. (1969). Protoplast formation and cell wall composition of some Oomycete species. PhD thesis, University of Amsterdam. UPDEGRAFF, D. M. (1969). Semi-micro determination of cellulose in biological materials. Analytical Biochemistry 32, 420-424.

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Section: Discussionmentioning

confidence: 99%

Distribution of (l->3)- - and (l->4)- -Glucan Synthases Along the Hyphae of Saprolegnia monoica

Girard

Fèvre

1984

Microbiology

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“…Hyphal fractionation of Aspergillus niduluns mycelium was previously described (Isaac et al , 1978(Isaac et al , , 1979Isaac & Gokhale, 1983;Gokhale & Isaac, 1984) using either 0.6 M-KC~ or 0.6 M-MgSO, as stabilizers, buffered to pH 5.8 with sodium phosphate buffer. The characteristics of lytic digestion of A .…”

Section: Discussionmentioning

confidence: 99%

“…Fungal protoplasts are recognized as being important in the preparation of cell-free extracts (Coakley eta/., 1977) and also in the investigation of the biochemical anatomy of fungal hyphae (Peberdy, , 1979Isaac, 1985). Protoplasts possess properties very similar to those of intact mycelium (Isaac, 1978;Isaac & Gokhale, 1983;Gokhale & Isaac, 1984), after allowing for the degree and nature of any inevitable disruption which occurs during their formation, and subsequent effects on their biochemistry.…”

Section: Introductionmentioning

confidence: 99%

Selectivity to K+ and Na+ of Protoplast Fractions Isolated from Different Regions of Aspergillus nidulans Hyphae

Isaac¹,

Gokhale²,

Wyatt³

1986

Microbiology

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The selectivity to K+ and Na+ of protoplast samples representing cytoplasm isolated from different regions of the hyphal filament of Aspergillus nidulans was investigated. Concentrations of both ions contained in successive protoplast fractions were measured. During lytic digestion, protoplasts were released first from apical regions and subsequently from progressively older regions of hyphae. A low K+/Na+ ratio was found in protoplasts containing primarily apical cytoplasm and a high K+/Na+ ratio was found in protoplasts originating from older regions of hyphae. The ratios were the same whether MgSO4 or mannitol was used as stabilizer. Absolute concentrations of both ions were higher in protoplasts of apical origin. Protoplasts stabilized in mannitol lost more ions than those stabilized in MgSO4 over an 8 h incubation period. Na+ losses were higher from apical protoplasts whereas K+ losses were higher from protoplasts liberated from older regions of hyphae. The addition of divalent metal cations (1.5 mM-Mn2+ or Mg2+) reduced losses of Na+ from protoplasts but did not affect loss of K+. Data obtained using protoplast samples were related to those obtained for intact mycelium. Absolute losses of both ions from mycelium were lower than for protoplasts but when compared on a protein basis the data suggested that protoplasts possess properties similar to those of intact mycelium in terms of K+ and Na+ selectivity.

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Respiration of Protoplasts Isolated from Aspergillus Nidulans

Cited by 2 publications

References 3 publications

Distribution of (l->3)- - and (l->4)- -Glucan Synthases Along the Hyphae of Saprolegnia monoica

Distribution of (l->3)- - and (l->4)- -Glucan Synthases Along the Hyphae of Saprolegnia monoica

Selectivity to K+ and Na+ of Protoplast Fractions Isolated from Different Regions of Aspergillus nidulans Hyphae

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