Transformation frequencies are enhanced and vector DNA is targeted during retransformation of Leptosphaeria maculans, a fungal plant pathogen

Leptosphaeria maculans, a fungal pathogen of Brassica spp., was successfully transformed with the vector pAN8-1, encoding phleomycin resistance. Protoplasts of a vigorous Phleor transformant were then retransformed using the partially homologous vector, pAN7-1 which encodes hygromycin B resistance....

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Main Authors: Farman, M., Oliver, Richard
Format: Journal Article
Published: 1992
Online Access:http://hdl.handle.net/20.500.11937/45236
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author Farman, M.
Oliver, Richard
author_facet Farman, M.
Oliver, Richard
author_sort Farman, M.
building Curtin Institutional Repository
collection Online Access
description Leptosphaeria maculans, a fungal pathogen of Brassica spp., was successfully transformed with the vector pAN8-1, encoding phleomycin resistance. Protoplasts of a vigorous Phleor transformant were then retransformed using the partially homologous vector, pAN7-1 which encodes hygromycin B resistance. Retransformation of this strain to hygromycin resistance occurred at frequencies that were consistently twofold higher than with the original recipient strain. Linearised pAN7-1 DNA transformed phleomycin-resistant protoplasts at higher frequencies still. All the transformants that were tested retained a phleomycin-resistant phenotype (20/20). Molecular analysis of five transformants generated with circular pAN7-1 DNA indicated that in four cases the pAN7-1 vector had integrated into pAN8-1 sequences. These results suggest that transformation frequencies in L. maculans are limited by the ability of vector DNA to integrate into the genome. Hence, construction of strains with target sites for integration may prove to be a generally useful method for improving transformation frequencies of poorly characterised filamentous fungi, particularly when using heterologous vectors. This would greatly facilitate the identification of genes by transfer of gene libraries and the standardisation of chromosomal location effects in studies of expression of nested promoter deletions.
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spelling curtin-20.500.11937-452362017-09-13T16:01:01Z Transformation frequencies are enhanced and vector DNA is targeted during retransformation of Leptosphaeria maculans, a fungal plant pathogen Farman, M. Oliver, Richard Leptosphaeria maculans, a fungal pathogen of Brassica spp., was successfully transformed with the vector pAN8-1, encoding phleomycin resistance. Protoplasts of a vigorous Phleor transformant were then retransformed using the partially homologous vector, pAN7-1 which encodes hygromycin B resistance. Retransformation of this strain to hygromycin resistance occurred at frequencies that were consistently twofold higher than with the original recipient strain. Linearised pAN7-1 DNA transformed phleomycin-resistant protoplasts at higher frequencies still. All the transformants that were tested retained a phleomycin-resistant phenotype (20/20). Molecular analysis of five transformants generated with circular pAN7-1 DNA indicated that in four cases the pAN7-1 vector had integrated into pAN8-1 sequences. These results suggest that transformation frequencies in L. maculans are limited by the ability of vector DNA to integrate into the genome. Hence, construction of strains with target sites for integration may prove to be a generally useful method for improving transformation frequencies of poorly characterised filamentous fungi, particularly when using heterologous vectors. This would greatly facilitate the identification of genes by transfer of gene libraries and the standardisation of chromosomal location effects in studies of expression of nested promoter deletions. 1992 Journal Article http://hdl.handle.net/20.500.11937/45236 10.1007/BF00279797 restricted
spellingShingle Farman, M.
Oliver, Richard
Transformation frequencies are enhanced and vector DNA is targeted during retransformation of Leptosphaeria maculans, a fungal plant pathogen
title Transformation frequencies are enhanced and vector DNA is targeted during retransformation of Leptosphaeria maculans, a fungal plant pathogen
title_full Transformation frequencies are enhanced and vector DNA is targeted during retransformation of Leptosphaeria maculans, a fungal plant pathogen
title_fullStr Transformation frequencies are enhanced and vector DNA is targeted during retransformation of Leptosphaeria maculans, a fungal plant pathogen
title_full_unstemmed Transformation frequencies are enhanced and vector DNA is targeted during retransformation of Leptosphaeria maculans, a fungal plant pathogen
title_short Transformation frequencies are enhanced and vector DNA is targeted during retransformation of Leptosphaeria maculans, a fungal plant pathogen
title_sort transformation frequencies are enhanced and vector dna is targeted during retransformation of leptosphaeria maculans, a fungal plant pathogen
url http://hdl.handle.net/20.500.11937/45236