Many plant species are induced to flower by stress. Stress-induced flowering has been studied mostly in the short-day plant pharbitis (also called Japanese morning glory; Ipomoea nil, formerly Pharbitis nil). In this article, physiological characteristics, the regulation by salicylic acid (SA) and the expression of flowering-related genes in stress-induced flowering in pharbitis are reviewed. P...

A split plot factorial 2 × 3 experiment was designed to examine and characterize the relationships among secondary metabolites (total phenolics, TP; total flavonoids, TF), carbohydrate content, C/N ratio, protein synthesis and L–phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity in the Malaysian medicinal herb Labisia pumila (Blume) FernVill. under different CO2 concentrations (400 = ambien...

The loss of morphogenetic potential in bean suspension cultures has been investigated by measuring the amounts of phenylalanine ammonia-lyase activity induced in the cells when they are transferred from a medium in which they are grown and maintained to an induction medium. The tissue has been grown in 2 types of medium: (1) supplemented with 2,4-dichlorophenoxyacetic acid as the only growth ho...

Divalent Mn ions cause an increase in the level of phenylalanine ammonia-lyase in gherkin hypocotyls. With the exception of Mg ions, which had a small effect, no other metal ion has so far been found which could replace the Mn ion in this respect. Invertase and peroxidase were not significantly affected by the Mn treatment. The increase in phenylalanine ammonialyase activity is explained by the...

Wounding during the preparation of fresh-cut lettuce induces the synthesis of phenylalanine ammonia lyase (PAL, EC 4.3.1.5), and the synthesis and accumulation of specific phenolic compounds (e.g., chlorogenic acid) that contribute to subsequent tissue browning. Increased PAL activity and phenolic content were not induced in non-wounded lettuce that was kept in close proximity to wounded tissue...

Arbuscular mycorrhizal fungi (AMF) species and/or phosphorus addition in the soil can affect secondary metabolism production and growth plants. This study evaluated these effects on Piper divaricatum culture, which presents an essential oil rich phenylpropanoids. Growth parameters, leaf volatile composition, total phenolic content, enzymatic activity of lipoxygenase (LOX) phenylalanine ammonia-...

Phenylalanine ammonia-lyase, which irreversibly deaminates phenylalanine and tyrosine, markedly inhibited the growth of human leukemic and murine L5178Y lymphoblasts in vitro but had a negligible effect on resting (nondividing) normal lymphocytes. These studies also demonstrated that phenylalanine ammonia-lyase inhibited DNA synthesis in leukemic cells at least as effectively as did asparaginas...

Abstract The cereal aphids Rhopalosiphum padi L. are serious pests on grain crops, reducing the quality and yield by direct feeding damage virus transmission. changes in physiological biochemical parameters of two wheat cultivars under aphid stress were investigated to understand aphid-resistance mechanisms. activity levels phenylalanine ammonia-lyase (PAL), peroxidase (POD), tyrosine (TAL), Ca...

Yeast phenylalanine ammonia-lyase (EC 4.3.1.5) catalyzes the deamination of L-phenylalanine to form trans-cinnamic acid and tyrosine to trans-coumaric acid. Maximal enzyme activity in Rhodotorula glutinis (2 units/g, wet weight, of yeast) was induced in late-log phase (12 to 14 hours) of growth in a culture medium containing 1.0% malt extract, 0.1% yeast extract, and 0.1% L-phenylalanine. A hig...

Phenylketonuria (PKU), with its associated hyperphenylalaninemia (HPA) and mental retardation, is a classic genetic disease and the first to have an identified chemical cause of impaired cognitive development. Treatment from birth with a low phenylalanine diet largely prevents the deviant cognitive phenotype by ameliorating HPA and is recognized as one of the first effective treatments of a gen...