Like seed plants, liverworts synthesize and accumulate a myriad of isoprenoid compounds. Using antibodies raised against several isoprenoid biosynthetic enzymes, we investigated their intracellular compartmentation by in situ immunolocalization from Marchantia polymorpha. The enzymes examined were deoxy-xylulose phosphate synthase, geranyl diphosphate synthase, farnesyl diphosphate synthase, ge...

The immutans (im) mutant of Arabidopsis shows a variegated phenotype comprising albino and green somatic sectors. We have cloned the IM gene by transposon tagging and show that even stable null alleles give rise to a variegated phenotype. The gene product has amino acid similarity to the mitochondrial alternative oxidase. We show that the IM protein is synthesized as a precursor polypeptide tha...

Under stress conditions such as high light intensity or nutrient starvation, cells of the unicellular alga Dunaliella bardawil overproduce b-carotene, which is accumulated in the plastids in newly formed triacylglycerol droplets. We report here that the formation of these sequestering structures and b-carotene are interdependent. When the synthesis of triacylglycerol is blocked, the overproduct...

1. Chloroplasts prepared by the non-aqueous technique will, after fragmentation by ultrasonic treatment, incorporate [2-14C]mevalonic acid into phytoene, the first C40 compound formed in the biosynthetic sequence to coloured carotenoids. 2. With suspensions containing 3*5mg. of chlorophyll, the optimum amounts of cofactor required were ATP (10,umoles), magnesium chloride (20,umoles) and glutath...

A variety of 4-aryl- and 4-alkyl-3-(substituted benzylthio)-4H-1,2,4-triazoles were prepared and evaluated for their bleaching activity by the lettuce seedling test. Among the series of tested compounds, 4-(3-fluorophenyl)-3-(4-trifluoromethylbenzylthio)-4H-1,2,4-triazole (39) exhibited the highest bleaching activity, causing complete bleaching symptoms at 10 microM. In the dark condition, comp...

Bleaching herbicides inhibit carotene biosynthesis in photosynthetic organisms. The interaction of norflurazon [4-chloro-5-methylamino-2-(3-trifluoromethylphenyl)-pyridazin-3(2H)one] with its target enzyme phytoene desaturase, has been characterized by enzyme-kinetic studies. A Lineweaver-Burk plot showed a non-competitive manner for norflurazon inhibition. Binding of norflurazon to phytoene de...

The phytoene desaturase (PDS) encodes a crucial enzyme in the carotenoid biosynthesis pathway. Silencing or inhibiting PDS expression leads to appearance of mottled, chlorosis, albino leaves. In this study, CDS sequence EuPDS (Eucommia ulmoides Phytoene Desaturase) was first cloned and then silenced Nicotiana benthamiana. Result showed level leaves higher than that roots stems. N. benthamiana l...

CoQ10 and lycopene are isoprenoid compounds with nutraceutical and pharmaceutical benefits. In this study, the effect of concomitant lycopene biosynthesis on CoQ10 accumulation in transformed Escherichia coli DH5α was studied. A lycopene production pathway including geranylgeranyl diphosphate synthase (crtE), phytoene synthase (crtB), and phytoene desaturase (crtI) from Erwinia herbicola was co...

360 © 2014 Guilford Publications, Inc. This research was supported by a Psi Chi Summer Research Grant, a National Science Foundation Graduate Research Fellowship, and a Regina Casper Stanford Graduate Fellowship awarded to the first author. Address correspondence regarding this research to Takuya Sawaoka, Stanford University, Department of Psychology, 450 Serra Mall, Jordan Hall, Stanford, CA 9...