Abstract
Salicylic acid (SA) is synthesized from both phenylalanine and isochorismate. SA biosynthesis under ozone fumigation had not been well defined. In this research, we examined the regulation of SA synthesis in ozone-exposed Arabidopsis. Increase of SA level was observed in ozone-exposed wild type Arabidopsis (Col-0), but not in sid2 which defect isochorismate synthase 1. This result indicates ozone-exposed Arabidopsis synthesizes SA from isochorismate. SA level of etr1 and ein2, that are ethylene signaling deficient mutant, were higher than that of wild type under ozone fumigation. Ethylene production from both etr1 and ein2 was higher than that of wild type. These results suggest that ethylene signaling play a role as negative regulator of SA synthesis in ozone exposure. Or, ethylene may regulate SA synthesis positively by another unknown signaling pathway in response to ozone exposure.
Arabidopsis
