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...

The time course and spatial distribution of wound-induced activities of phenylalanine ammonia-lyase and peroxidase were determined to establish correlations between molecular and cellular aspects of the wound-induced pattern of cell differentiation in potato (Solanum tuberosum L.) tissue. A high correlation between peroxidase activity and suberization was observed. Peroxidase activity increased...

Potato (solanum tuberosum L. cv Katahdin) tuber discs treated with arachidonic acid become necrotic and accumulate sesquiterpenoid phytoalexins. The arachidonic acid also causes increases in both phenylalanine ammonia lyase and lignin, but no change in total alcohol-soluble phenols. Linoleic acid does not alter any of these parameters. A high concentration of nonanoic acid promotes both necrosi...

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...

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 ...