| Systemic acquired resistance (SAR) was activated by benzothiadiazole (BTH) and induced systemic resistance (ISR) was activated by (2R,3R)-butanediol or PC1, a new isoparaffin compound developed by Petro-Canada, against anthracnose caused by Colletotrichum orbiculare in Nicotiana benthamiana. BTH, (2R,3R)-butanediol and PC1 reduced the number of lesions per leaf area of C. orbiculare by 98%, 77% and 81%, respectively. Foliar application of BTH also induced expression of pathogenesis-related (PR) genes, NbPR-1a, NbPR-3Q and acidic NbPR-5, and soil application of (2R,3R)-butanediol or PC1 primed expression of NbPRb-1b, basic NbPR-2 and NbPR-5dB. BTH also activated resistance against dollar spot caused by Sclerotinia homoeocarpa in Agrostis stolonifera , reducing the percentage of diseased leaves by 50%, but BTH did not activate resistance against diseases caused by Microdochium nivale ,or Rhizoctonia solani. However, application of either (2R,3R)-butanediol or PC1 reduced the area diseased leaves by 20 to 40% for M. nivale, R. solani or S. homoeocarpa. In A. stolonifera, expression of the jasmonate-related genes, AsAOS1 and AsOPR4, and the PR gene, AsGns5 was primed by both (2R,3R)-butanediol and PC1, while BTH did not affect the expression of homologs in A. stolonifera of BTH-inducible genes identified in other monocots, the WCI-2 lipoxygenase or the BCI-4 putative calcium-binding EF-hand. |
