Calcium translocation, calcium oxalate accumulation, and hyphal sheath morphology in the white-rot fungusResinicium bicolor

Abstract

The white-rot fungus Resinicium bicolor was cultured on wood blocks in a modified soil block assay and was observed by environmental scanning electron microscopy and scanning electron microscopy. Resinicium bicolor was found to translocate calcium in mycelial cords in quantities greater than that found in the wood blocks and accumulated this calcium in the form of calcium oxalate. Calcium oxalate crystal clusters of mycelial cords were 3 × larger and far more numerous than the crystal clusters produced by the same fungus within the wood. Environmental scanning electron microscopy technology allowed for the examination of the hyphal sheath in a hydrated state. The hydrated hyphal sheath was found to be much thicker than the desiccated sheath observed after standard scanning electron microscope preparations. Calcium oxalate crystals were found to be embedded in the thick hyphal sheath, suggesting that previous observations of within-wall calcium oxalate precipitation may perhaps be better interpreted as artifacts generated during sample preparation. Key words: calcium oxalate, hyphal sheath, environmental scanning electron microscopy.

Furfurylated wood: impact onPostia placentagene expression and oxalate crystal formation

“…The OA and OX data show an OX increment in W FA during incubation and a corresponding decrease in W, but the data cannot be explained by crystal formation in W FA alone. Many fungi, both brown-and white rot fungi can produce Ca-OX crystals that adhere to the hyphae (Connolly and Jellison 1995) and are located within the fungal sheath. It has been suggested that Ca-OX precipitation along the hyphae of fungi can be an intracellular, periplasmic, or intramural nucleation with subsequent exteriorisation of the growing crystals (Connolly and Jellison 1995).…”

“…Many fungi, both brown-and white rot fungi can produce Ca-OX crystals that adhere to the hyphae (Connolly and Jellison 1995) and are located within the fungal sheath. It has been suggested that Ca-OX precipitation along the hyphae of fungi can be an intracellular, periplasmic, or intramural nucleation with subsequent exteriorisation of the growing crystals (Connolly and Jellison 1995). The substrate pH modulation facilitates the activity of fungal extracellular enzymes that have pH optima below 5 (Punja et al 1985).…”

Quantitative determination of calcium oxalate and oxalate in developing seeds of soybean (Leguminosae)

“…This latter procedure has been used to qualitatively identify the presence of oxalate in white rot fungus (Connolly and Jellison, 1995). The SIGMA method involves degradation of oxalate by oxalate oxidase and combining the degradation product, hydrogen peroxide, with two substrates that form a colored complex, measurable by colorimetry.…”

Morphological and molecular studies on Resinicium s. str.

“…Encrusted spines de veloped on the subicular hyphae of some species appear to be a reduced form of astrocystidia. For scanning electron micrographs of astrocystidia and crystal clusters, see Keller (1985) and Connolly and Jellison (1995).…”