Expression of the Talaromyces flavus glucose oxidase gene in cotton and tobacco reduces fungal infection, but is also phytotoxic.

Autor: Murray, Fiona, Llewellyn, Danny, McFadden, Helen, Last, David, Dennis, Elizabeth, Peacock, W.
Zdroj: Molecular Breeding; Mar1999, Vol. 5 Issue 3, p219-232, 14p
Abstrakt: Glucose oxidase secreted by the fungus Talaromyces flavus generates, in the presence of glucose, hydrogen peroxide that is toxic to phytopathogenic fungi responsible for economically important diseases in many crops. A glucose oxidase gene from T. flavus, was modified with a carrot extensin signal peptide and fused to either a constitutive or root-specific plant promoter. T1 tobacco plants expressing the enzyme constitutively were protected against infection by the seedling pathogen Rhizoctonia solani. Constitutive expression in tobacco was associated with reduced root growth, and slow germination on culture medium, and with reduced seed set in glasshouse conditions. Several independent transformed cotton plants with a root-specific construct expressed high glucose oxidase activity in the roots, excluding the root tip. Selected T3 homozygous lines showed some protection against the root pathogen, Verticillium dahliae, but not against Fusarium oxysporum. High levels of glucose oxidase expression in cotton roots were associated with reduced height, seed set and seedling germination and reduced lateral root formation. If this gene is to be of value for crop protection against pathogens it will require precise control of its expression to remove the deleterious phenotypes. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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