Abstract
Volatiles released from a plant induce gene expressions and root-growth inhibitions in other plants. However, molecular mechanism of the volatile reception has not been elucidated. We assume that G-protein-coupled receptors (GPCRs), odorant receptors in animals, might detect volatiles also in plants. We found six GPCR-like genes, AtGPCR1-6, on Arabidopsis thaliana genome. Transcripts of these genes were detected in tissues of A. thaliana. Expressions of AtGPCR1 and AtGPCR6, however, were less in flowers and buds than other tissues. This is also the case of the expression of GPA1 (α subunit gene of heterotrimeric G protein) , suggesting that AtGPCR1 and AtGPCR6 have functional relations with GPA1. On the other, AtGPCR2 and AtGPCR5 were more expressed in flowers and buds. Bornyl acetate, a plant terpenoid, induced the expression of LOX (lipoxygenase gene) in wild type, but not in a mutant of AtGPCR5 which is knocked out by inserting T-DNA.
