Microsomal preparations from osmotically stressed soybean cells catalyze the conversion of (25)-naringenin to apigenin in presence of N A D P H . In contrast, such preparations from normal soybean cells or from elicitor-challenged cells catalyze the conversion o f (25)-naringenin to genistein (isoflavone synthase). It is concluded that osm otic stress of the cells causes a switch from isoflavon...

Flavones are plant secondary metabolites that have wide pharmaceutical and nutraceutical applications. We previously constructed a recombinant flavanone pathway by expressing in Saccharomyces cerevisiae a four-step recombinant pathway that consists of cinnamate-4 hydroxylase, 4-coumaroyl:coenzyme A ligase, chalcone synthase, and chalcone isomerase. In the present work, the biosynthesis of flavo...

Arabidopsis thaliana lacks the flavone biosynthetic pathway, probably because of a lack or low activity of a flavone synthase. To establish this biosynthetic pathway in Arabidopsis, we subjected this model plant to transformation with the parsley gene for flavone synthase type I (FNS-I). Transgenic seedlings expressing FNS-I were cultured in liquid medium with or without naringenin, and plant e...

Flavonoid Biosynthesis, Chalcone Synthase, Flavonoid 3'-Hydroxylase, Flavone Synthase II, Sinningia cardinalis Flowers of Sinningia (syn. Rechsteineria) cardinalis contain glycosides of the flavones apigenin (4'-O H ) and luteolin (3',4'-O H ) respectively, and of the related 3-deoxyanthocyanidins apigeninidin and luteolinidin. Studies on substrate specificity of the key enzyme o f flavonoid bi...

Flavones are synthesized from flavanones through the action of flavone synthases (FNSs). There are two FNSs, FNS I and II. FNS I is a soluble dioxygenase present in members of the Apiaceae family and FNS II is a membrane bound cytochrome P450 enzyme that has been identified in numerous plant species. In this study, we cloned OsFNS I-1 from rice by RTPCR, expressed it in E. coli, and purified th...

A cDNA encoding flavone synthase I was amplified by RT-PCR from leaflets of Petroselinum crispum cv. Italian Giant seedlings and functionally expressed in yeast cells. The identity of the recombinant, 2-oxoglutarate-dependent enzyme was verified in assays converting (2S)-naringenin to apigenin.

Following inoculation with the anthracnose pathogen Colletotrichum sublineolum, seedlings of the sorghum resistant cultivar SC748-5 showed more rapid and elevated accumulation of luteolin than the susceptible cultivar BTx623. On the other hand, apigenin was the major flavone detected in infected BTx623 seedlings. Luteolin was demonstrated to show stronger inhibition of spore germination of C. s...

Cumin, Cuminum cyminum L., is the king of spices with a plethora of natural compounds with pharmacological features. Drought stress is a well-known factor that influences the production of some metabolites. We studied the impact of drought stress on gene expression and metabolite content in flower and leaf tissue organs of two ecotypes, Taybad and Ardakan populations. Plants were imposed into t...

Flavones are a major class of flavonoids with a wide range of physiological functions in plants. They are constitutively accumulated as C-glycosides and O-linked conjugates in vegetative tissues of grasses. It has long been presumed that the two structural modifications of flavones occur through independent metabolic routes. Previously, we reported that cytochrome P450 93G2 (CYP93G2) functions ...