Oat Retrotransposon OARE-1 Is Activated in Both Compatible and Incompatible Interactions with Pathogenic Fungi

Transcriptional activity of the retrotransposon OARE-1 was monitored in oat leaves infected with pathogenic fungi. The transcription of OARE-1 was upregulated in both incompatible and compatible interactions between an oat cultivar and Magnaporthe grisea isolates but more extensively in the compatible. OARE-1 was also strongly activated in a Pc2/vb -carrying oat line inoculated with Helminthosporium victoriae. The upregulation in the Pc2/Vb -carrying oat line was reproduced by treatment with victorin C, the major compound of the host-specific toxin produced by the fungus. These results suggest that OARE-1 is responsive to various signals or stresses associated with compatibility and incompatibility.