T-DNA transfer from Agrobacterium tumefaciens to the ectomycorrhizal fungus Pisolithus microcarpus / Transferencia de T-DNA de Agrobacterium tumefaciens al hongo ectomicorrícico Pisolithus microcarpus

The model ectomycorrhizal fungus Pisolithus microcarpus isolate 441 was transformed by using Agrobacterium tumefaciens LBA1100 and AGL-1. The selection marker was the Shble gene of Streptoallotecius hidustanus, conferring resistance to phleomycin, under the control of the gpd gene promoter and terminator of Schizophyllum commune. Transformation resulted in phleomycin resistant clones which were confirmed by PCR to contain the resistance cassette. A. tumefaciens-mediated gene transfer would allow the development of RNA interference technology in P. microcarpus.

El hongo ectomicorrícico modelo Pisolithus microcarpus aislamiento 441 fue transformado utilizando Agrobacterium tumefaciens LBA 1100 y AGL-1. El marcador de selección fue el gen Shble de Streptoallotecius hidustanus, el cual confiere resistencia a fleomicina, bajo el control del promotor y terminador del gen gpd de Schizophyllum commune. La transformación resultó en clones resistentes a fleomicina comprobándose por PCR la presencia del transgen. La transferencia génica mediada por Agrobacterium podría permitir el desarrollo de la tecnología de interferencia por ARN en P. microcarpus.

Transformation of the Edible Basidiomycete, Pleurotus ostreatus to Phleomycin Resistance

For transformation of Pleurotus ostreatus, two novel vectors, pPhKM1 and pPhKM2, were constructed, using the regulatory sequences of the P. sajor-caju beta-tubulin gene (TUB1) and the ble gene encoding phleomycin binding protein. pPhKM1 contains ble fused to the TUB1 promoter and the Schizophyllum commune GPD terminator. pPhKM2 contains ble fused to the promoter and terminator regions of P. sajor-caju TUB1. To confirm phleomycin-resistance activity, each vector was cotransformed with pTRura3-2 into the P. ostreatus homokaryotic ura - strain. The transforming DNA was stably integrated into the genomic DNA. Subsequently, phleomycin resistance was conferred on wild-type dikaryotic P. ostreatus by transformation with pPhKM1 or pPhKM2. This transformation system generated stable phleomycin-resistant transformants.

Improvement of Transformation System in Filamentous Fungus Aspergillus oryzae / 대한의진균학회지

Aspergillus oryzae is a filamentous fungus classified in the group Aspergillaceae Ascomycetes. A. oryzae is an important microorganism for industrial production of enzymes and fermented food products. It secrets large quantities of proteins or enzymes into the culture medium which makes this organism appealing for the production of heterologous proteins. Recently Electric field-mediated transformation method, electroporation, has been applied to fungal transformation. It is fast, simple to handle, and avoids the use of some chemicals. The optimum conditions for A. oryzae were determined with pILJ-16 and ~0.2 x 105 protoplast cell at various field strength. The survived population of protoplasts in the electric field were ~80% of nonprotoplast cell population at 1.3 KV/cm to ~50% at 6.3 KV/cm. The electrotransformation efficiency, expressed as transformants/microgram of input DNA/population of protoplast cells, increased with the increment of the field strength up to 6.3 KV/cm. The highest value, 14.35%, was obtained at 6.3 KV/cm and 1540ohm. Some antibiotics for the dominant selectable makers were applied to A. oryzae and Tolypocladium inflatum. Whereas phleomycin was very effective on T. inflatum, hygromycin B and phleomycin were not effective on A. oryzae. Protoplasts were obtained with hemicellulase and celluclast, instead of novozyme234. More than 104 transformants/microgram of DNA with hemicellulase-treated protoplasts were obtained by using electroporation at the condition of 2,500 voltage, 1,540 ohm and 0.50 capacitance. Less than 102 transformants/microgram of DNA were obtained with Novozyme234- and celluclast-treated protoplasts.