The effects of gibberellic acid on lignification in seedlings of a dwarf and a tall cultivar of pea (Pisum sativum) grown under red or white light or in the darkness, were studied. Gibberellic acid (10(-6)-10(-4)m) promoted stem elongation in both light and dark and increased the percentage of lignin in the stems of the light-grown dwarf pea. The gibberellin had no effect on the lignin content ...

To assess nickel-induced toxicity in plants, Zea mays seeds were germinated and cultured on nutrient solution with nickel concentrations of 50-200 μM for a period of two weeks. Observed biological makers included biomass, soluble and total protein contents, and the activities of guaiacol peroxidase (GPX), ascorbate peroxidase (APX), catalase (CAT), and phenylalanine ammonia-lyase (PAL) in the l...

In order to study on different methods of application of polyamines (putrescine, spermine, spermidine) on some morphological, physiological, enzymatic and vase life of Rosa hybrida cv. ‘Dolce Vita’, experiment was conducted as a factorial experiment in a completely randomized design with 32 treatments, 3 replicates and each replication containing 5 vases, a total of 480 vases were executed. Fir...

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...

Using DNA probes specific for the three members of the bean (Phaseolus vulgaris L.) phenylalanine ammonia-lyase (PAL) gene family, we have studied the effects of the product of the PAL reaction, trans-cinnamic acid (CA), on the appearance of individual PAL transcripts in suspension cultured bean cells. Concentrations of CA in excess of 10(-4) molar inhibited appearance of elicitor-induced trans...

Etiolated hypocotyls of the resistant soybean (Glycine max [L.] Merr.) cultivar Harosoy 63 became susceptible to Phytophthora megasperma (Drechs.) f.sp. glycinea (Hildeb.) Kuan and Erwin race 1 after treatment with abscisic acid. Susceptibility was expressed by increases in lesion size and a major decrease in accumulation of the isoflavonoid phytoalexin, glyceollin. In untreated hypocotyls, act...

Enzyme substitution therapy with the phenylalanine ammonia lyase (PAL) is a new approach to the treatment of patients with phenylketonuria (PKU). This enzyme is responsible for the conversion of phenylalanine to trans-cinnamic acid. We assessed the PAL enzyme of the endemic plant Cyathobasis fruticulosa (Bunge) Aellen. for its possible role in the dietary treatment of PKU. The enzyme was found ...

Immobilized metal ion affinity chromatography principles were applied for selective immobilization of recombinant polyhistidine tag fused phenylalanine ammonia-lyase from parsley (PcPAL) on porous polymeric support with aminoalkyl moieties modified an EDTA dianhydride (EDTADa)-derived chelator and charged transition ions. Out the five investigated ions - Fe3+, Co2+, Ni2+, Cu2+, Zn2+ best biocat...

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...

l-Phenylalanine ammonia-lyase (E.C. 4.3.1.5) from maize is active with l-tyrosine and l-phenylalanine and exhibits atypical Michaelis-Menten kinetics with both substrates. With phenylalanine as a substrate, the pH optimum is 8.7 and with tyrosine, 7.7. The estimated Km at high substrate concentrations is 0.27 mm for phenylalanine and 0.029 mm for tyrosine. However, the V(max) with phenylalanine...