Abstract
Although jasmonic acid (JA) has been shown to be required for the elongation of stamens and petals and dehiscence of anthers, little is known how the biosynthesis of JA is turned on. We found that the level of DAD1 mRNA was decreased in the inflorescences of arf6 arf8 double mutant, which showed the depletion of JA. This depletion was partially rescued by the introduction of PPISTILLATA:DAD1 into the mutant. The arf6 arf8 double mutant shows several developmental defects such as aberration of vascular and epidermal cell differentiation. We found that the expressions of class I KNOX genes are upregulated in the mutant and that the arf6 arf8 stm+/- plants partially rescued the DAD1 expression and JA production. These results suggested that the repression of KNOX genes by ARF6/8 is required for the development of floral organs, and subsequently for the DAD1 expression and JA production, which induces the flower opening.
