Abstract
The plant activators are very useful for crop disease control and management. However, it is difficult to screen novel plant activators because these have no toxic effect against fungi and bacteria, and it works only through the plant. To obtain novel plant activators, we developed a system using Arabidopsis transformants to monitor the expression profiles of defense-related genes in response to chemical treatment. We used Arabidopsis gene PR-1, PR-4 and AtPLA IIA as a marker for the SA-, JA/ET- and multiple-signal transduction pathways, respectively. Transgenic Arabidopsis plants harboring PR-1, PR-4 and AtPLA IIA promoter fused to the β-glucuronidase (GUS) gene were generated to investigate the regulated gene expression. We performed the GUS reporter gene assay for screening of plant activators. One thousand chemicals were screened, and the sequent several candidates for plant activator were isolated. In this report, we will discuss a mode of action for candidate plant activators.
