EXPANSION AND VARIABILITY OF THE PTR TOX A GENE IN POPULATIONS OF PYRENOPHORA TRITICI-REPENTIS AND PYRENOPHORA TERES

Abstract

Ptr ToxA was the first proteinaceous, necrosis-inducing toxin identified and cloned from the wheat pathogen Pyrenophora tritici-repentis. It acts as a pathogenic factor and was transferred from another wheat pathogen, Stagonospora nodorum. No sequence variability of the Ptr ToxA gene was found within a P. tritici-repentis population, indicating its probable recent transfer into the genome. The Ptr ToxA gene was detected in isolates of Pyrenophora teres, predominantly a barley pathogen. A study on the presence of Ptr ToxA gene within a central European P. teres population is reported and its consequences are discussed.