To clarify the involvement of actin in the formation of the yeast cell wall, reverting protoplasts of Schizosaccharomyces pombe were used as a simple model system. Actin of reverting protoplasts was labeled with rhodamine-conjugated phalloidin and observed by conventional fluorescence microscopy and laser scanning confocal microscopy. A close spatial as well as temporal relationship between act...

High frequencies of fusion were induced between isolated tobacco leaf protoplasts when they were incubated at 37 °C in the presence of 0.05 M CaCl2 in 0.4 m mannitol at pH 10.5. Subsequent to the fusion treatment the protoplasts were washed and cultured in a suitable medium and within two weeks, actively dividing cell colonies were observed. The fusion treatment had no irreversible, deleterious...

Tobacco mesophyll protoplasts were transfected with tobacco mosaic virus (TMV) RNA in an electric field using a newly devised chamber constructed with gold-coated glass panel electrodes. Up to 95 9/oo of protoplasts subjected to several DC pulses (50 Ixs, 550 to 800 V/cm) while suspended in 0.5 i-mannitol containing 10 ~tg/ml TMV RNA became infected. The treatment did not affect the viability o...

A simple method is described for the electrofusion of plant protoplasts. Protoplasts were aggregated in a radio-frequency field (10 V RMS, 0.5 MHz) for 15-30 s with an inter-electrode distance of 5 mm. They were then fused with a 300-V DC pulse. The protoplasts were able to divide after this treatment. A transferrable electrode permitted electrofusion of 1-ml volumes of culture in standard tiss...

A preparation of two commercial enzymes was used to liberate protoplasts from 16-h-old mycelium of Phanerochaete chrysosporium. Regeneration frequencies of up to 5% were attained when the protoplasts were plated in a medium containing 10% sorbose and 3% agar. Fusion of protoplasts from different auxotrophic strains in polyethylene glycol-Ca produced heterokaryons. Separation of the heterokaryon...

Experiments were carried out on four cell types: Chlorella sp., Tetraselmis sp., and mesophyll protoplasts of Dendrobium and Lilium longiflorum. The speed of cell translation in between a pair of cylindrical electrodes was measured at different solution conductivities (σs). For each field frequency, the speed was plotted against the gradient of electric field squared to obtain the real part Re[...

Almost all glucosyl transfer reactions rely on glucose-1-phosphate (Glc-1-P) that either immediately acts as glucosyl donor or as substrate for the synthesis of the more widely used Glc dinucleotides, ADPglucose or UDPglucose. In this communication, we have analyzed two Glc-1-P-related processes: the carbon flux from externally supplied Glc-1-P to starch by either mesophyll protoplasts or intac...

This investigation examines responses of protoplasts in a systematic and quantitative way to the various electrical treatments used to achieve electrofusion and their individual and cumulative effect on protoplast viability. Mesophyll and cell suspension protoplasts from two species of the same genera, Nicotiana tabacum and N. rustica var brasilia were used in these experiments. Optimal frequen...

We have established an Arabidopsis protoplast model system to study plant cell death signaling. The fungal toxin fumonisin B1 (FB1) induces apoptosis-like programmed cell death (PCD) in wild-type protoplasts. FB1, however, only marginally affects the viability of protoplasts isolated from transgenic NahG plants, in which salicylic acid (SA) is metabolically degraded; from pad4-1 mutant plants, ...

When auxin was omitted during either the preparation or the culture of tobacco mesophyll protoplasts, as well as during both periods, synthesis of beta-glucanase was spontaneously induced. In contrast, when protoplasts were prepared and cultured in the presence of 16 micromolar 1-naphthaleneacetic acid (optimal concentration for protoplast division), the expression of beta-glucanase was maintai...