Influences of light and darkness on l-phenylalanine ammonia-lyase activity of black locust (Robinia pseudoacacia) seedlings were studied. Light initiates both an increase in enzyme activity (or enzyme synthesis) and a subsequent decrease in activity. These dual influences of light create cyclic changes in l-phenylalanine ammonia lyase activity in continuous light. The cyclic changes in activity...

The photosynthetic procaryote Anacystis nidulans converts L-phenylalanine and L-tyrosine into benzoic acid and p-hydroxybenzoic acid, respectively. Results obtained with thylakoid fractions support the hypothesis that the reaction sequence is catalyzed by thylakoid-bound enzyme complexes consisting of phenylalanine ammonia-lyase and benzoate synthase of tyrosine ammonia-lyase and p-hydroxybenzo...

A cycloheximide-sensitive increase in the activity of phenylalanine ammonia-lyase (EC 4.3.1.5) occurs in Xanthium leaf disks exposed to light. Radioactive ammonia-lyase has been isolated by means of sucrose density gradient centrifugation and starch gel electrophoresis from disks fed l-isoleucine-U-(14)C or l-arginine-U-(14)C. The incorporation of radioactive amino acids into phenylalanine ammo...

Aromatic ammonia-lyases catalyze the non-oxidative ammonia elimination from aromatic Lamino-acids, producing α,β-unsaturated compounds. The members of this enzyme family are the phenylalanine ammonia-lyase (PAL, EC 4.3.1.24), (Hodgins, 1971) histidine ammonia-lyase (HAL, EC 4.3.1.3) (Givot et al., 1969; Wickner, 1969) and the tyrosine ammonia-lyase (TAL, EC 4.3.1.23) (Kyndt et al., 2002) cataly...

lignin is one of the major characteristics of plant secondary cell wall that provides structural rigidity for the cells and tissues and hydrophobicity to tracheary elements. internode tissues of aeluropus littoralis as a halophyte grass were sampled at different developmental stages (from the first to the fifth internodes ) and under different nacl concentrations. the influences of nacl and int...

in this study, trichoderma harzianum bi was evaluated for its capability to reduce the incidence and severity of the root-knot nematode, meloidogyne javanica, and fusarium wilt, f. oxysporum f. sp. lycopersici, as causal agents of a complex disease of tomato in the laboratory and greenhouse conditions. initial in vitro studies revealed that the parasitism of m. javanica eggs by t. harzianum bi ...

Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität Bochum, D-4630 Bochum. Bundesrepublik Deutschland Z. Naturforsch. 44c, 357—360 (1989); received January 9, 1989 Dedicated to Professor Achim Trebst on the occasion o f his 60th birthday Anthocyanin, L-a-Aminooxy-ß-phenylpropionic Acid, Phenylalanine Ammonia-Lyase, Hibiscus mutabilis When opening in the morning flowers of Hibiscus mutabilis L. ...

We analyzed lignin content and composition in transgenic tobacco (Nicotiana tabacum) lines altered in the expression of the early phenylpropanoid biosynthetic enzymes L-phenylalanine ammonia-lyase and cinnamate 4-hydroxylase (C4H). The reduction of C4H activity by antisense expression or sense suppression resulted in reduced levels of Klason lignin, accompanied by a decreased syringyl/guaiacyl ...

Phenylketonuria (PKU) was the first inherited metabolic disease in which dietary treatment was found to prevent the disease's clinical features. Treatment of phenylketonuria remains difficult due to progressive decrease in adherence to diet and the presence of neurocognitive defects despite therapy. This review aims to summarize the current literature on new treatment strategies. Additions to t...

The incorporation of [(14)C]phenylalanine and [1,6-(14)C]shikimic acid into tyrosine was investigated in the callus of Portulaca grandiflora, var. JR (L.). By inhibiting phenylalanine with 1-alpha-aminooxy-beta-phenyl-propionic acid and tyrosinase with 1-cysteine-HCl and hydrazine-hydrate, the possible synthesis of tyrosine from phenylalanine was demonstrated. Tetrahydropterine sulfate was an e...