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. 2007 Oct 29;13(1):130–143. doi: 10.2478/s11658-007-0047-5

Sclerotia of the acellular (true) slime mould Fuligo septica as a model to study melanization and anabiosis

Anna Krzywda 1, Elżbieta Petelenz 1,2, Dominika Michalczyk 1, Przemysław M Płonka 1,✉
PMCID: PMC6275577  PMID: 17965965

Abstract

Acellular (true) slime moulds (Myxomycetes) are capable of a transition to the stage of sclerotium — a dormant form of plasmodium produced under unfavourable environmental conditions. In this study, sclerotia of Fuligo septica were analyzed by means of electron paramagnetic resonance (EPR) spectroscopy. The moulds were cultivated in vitro on filter paper, fed with oat flour, and kept until the plasmodia began to produce sclerotia. The obtained sclerotia differed in colour from yellow through orange to dark-brown. The EPR spectra revealed a free radical, melanin-like signal correlated with the depth of the colour; it was strongest in the dark sclerotia. Sclerotization only took place when the plasmodia were starved and very slowly dried. Only the yellow sclerotia were able to regenerate into viable plasmodia. This suggests that myxomycete cytoplasm dehydration is an active process regulated metabolically. Plasmodial sclerotization may therefore serve as a convenient model system to study the regulation of cytoplasmatic water balance, and sclerotia as a convenient material for EPR measurements, combining the quality of plasmodia with the technical simplicity of the measurements characteristic of dry spores. Darkening of the sclerotia is most probably a pathological phenomenon connected with the impairment of water balance during sclerotization.

Key words: Aquaporins, Dehydration, EPR, Melanin, Myxomycetes, Pigmentation

Full Text

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Abbreviations used

DOPA

3,4-dihydroksyphenylalanine

DPPH

1,1-diphenyl-2-picrylhydrazyl

EPR

electron paramagnetic resonance

Footnotes

Paper authored by participants of the international conference: XXXIV Winter School of the Faculty of Biochemistry, Biophysics and Biotechnology of Jagiellonian University, Zakopane, March 7–11, 2007, “The Cell and Its Environment”. Publication costs were partially covered by the organisers of this meeting.

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