Regulation of floral scent production in petunia revealed by targeted metabolomics

摘要: Petunia hybrida line W115 (Mitchell) has large white flowers that produce a pleasant fragrance. By applying solid phase micro extraction (SPME) techniques coupled to GC-MS analysis, volatile emission was monitored in vivo using targeted metabolomics approach. Mature released predominantly benzenoid compounds of which benzaldehyde, phenylacetaldehyde, methylbenzoate, phenylethylalcohol, iso-eugenol and benzylbenzoate were most abundant. This had circadian rhythm reaching its maximum at dusk. During petal limb expansion two sesquiterpenes emitted by the petunia flowers, tentatively identified as germacrene D cadina-3,9-diene. In vitro analysis showed limbs stigma main producers benzenoids sesquiterpenes, respectively. Moreover, comparison indicated volatiles not stored during periods low but rather synthesized de novo. DNA-microarray revealed genes pathways leading production upregulated late day, preceding increase emission. RNA-gel blot analyses confirmed levels phenylalanine ammonia lyase (PAL) S-adenosyl methionine (SAM) synthase transcripts increased towards evening. Our results suggest is, least partly, regulated transcript level.