Two cDNAs (PhERS1 and PhETR2) encoding ethylene receptor homologues were cloned and characterized from petunia. Genomic Southern blot analysis revealed that small families of PhERS1-related and PhETR2-related genes exist in petunia. PhERS1 and PhETR2 are constitutively expressed in stem, flower bud, flower, and roots, with a very low level in leaves. High levels of both PhERS1 and PhETR2 transc...

A change of flower shape was observed in petunia corollas treated with 0.5 mM glyphosate. Glyphosate changed the flower symmetry from the actinomorphic type to the zygomorphic type. Corollas treated with glyphosate showed an increased free amino acid content. Free amino acid profiles in petunia corollas revealed that glyphosate had no significant effect on aromatic amino acid levels but increas...

Aurone synthase from Coreopsis grandiflora (cgAUS1), catalyzing conversion of butein to sulfuretin in a type-3 copper center, is a rare example of a polyphenol oxidase involved in anabolism. Site-directed mutagenesis around the CuA site of AUS1 was performed, and recombinant enzymes were analyzed by mass spectrometry. Replacement of the coordinating CuA histidines with alanine resulted in the p...

The flavonoids from flowers of transgenic Petunia ×hybrida Vilm. plants containing the Al gene from Zea mays L. were characterized. The A1 gene encodes the enzyme dihydroflavonol reductase and was introduced into a mutant petunia defective for this gene. Control, nontransgenic plants produced flowers that contained ≈ 50 ng anthocyanin/ 100 mg tissue dry weight. Anthocyanin distribution was 63% ...

Analysis of mutants with increased branching has revealed the strigolactone synthesis/perception pathway which regulates branching in plants. However, whether variation in this well conserved developmental signaling system contributes to the unique plant architectures of different species is yet to be determined. We examined petunia orthologs of the ArabidopsisMAX1 and MAX2 genes to characteriz...

Higher plant species diverged extensively with regard to the moment (flowering time) and position (inflorescence architecture) at which flowers are formed. This seems largely caused by variation in the expression patterns of conserved genes that specify floral meristem identity (FMI), rather than changes in the encoded proteins. Here, we report a functional comparison of the promoters of homolo...

The uptake and metabolism of the cytokinin benzyl adenine (BA) was compared in two lines of Petunia hybrida Vilm. differing in their shoot organogenic response. Leaf transfer experiments using shoot induction medium containing 4.4 micromolar BA showed that leaf explants from petunia line St40 required a shoot induction period of 6 to 10 days for commitment to shoot organogenesis; whereas leaf e...

Acylsugars are synthesized in the glandular trichomes of the Solanaceae family and are implicated in protection against abiotic and biotic stress. Acylsugars are composed of either sucrose or glucose esterified with varying numbers of acyl chains of differing length. In tomato (Solanum lycopersicum), acylsugar assembly requires four acylsugar acyltransferases (ASATs) of the BAHD superfamily. To...

In Arabidopsis the floral identity of meristems is specified by the expression of a handful of genes that are activated upon the cues from several pathways leading to flowering. One of these genes is LEAFY (LFY) from Arabidopsis, which encodes a transcription factor that directly activates the expression of the floral identity MADS-box gene APETALA1 (AP1). In petunia, LFY ortholog ABERRANT LEAF...

l-Phe, a protein building block and precursor of numerous phenolic compounds, is synthesized from prephenate via an arogenate and/or phenylpyruvate route in which arogenate dehydratase (ADT) or prephenate dehydratase, respectively, plays a key role. Here, we used Petunia hybrida flowers, which are rich in Phe-derived volatiles, to determine the biosynthetic routes involved in Phe formation in p...