Phenylalanine ammonia-lyase (PAL) and peroxidase (POD) enzyme activities, total phenolics and pyruvic acid (PA) (as pungency indicator) were measured in onion bulb tissues (c.v. Rouge Amposta) during storage at 4 and 20 3C. After 2 wk, PAL activity increased at 4 3C, but decreased at 20 3C, and after 4 wk, PAL activity at 20 3C was higher than activity observed at 4 3C. Peroxidase activity was ...

The study focuses on the effect of supplemental UV-B radiation on germination, seedling growth, chlorophyll a and b contents, soluble phenols, anthocyanins, flavones contents, phenylalanine ammonia lyase (PAL) activity and tyrosine ammonia lyase (TAL) activity of mash-bean (Vigna mungo (L.) Hepper.). Even though the germination velocity was substantially increased, the final germination percent...

Excising plant tissues has been found to increase the activity of phenylalanine ammonia-lyase (EC 4.1.3.5) (1, 4, 11, 12). This increase is probably due to de novo synthesis of this enzyme, since inhibitors of protein synthesis block the rise of PAL' activity (4, 11, 12). We suggested earlier (4) that the increase of PAL in gherkin hypocotyl segments was due to the release into the medium of re...

Pharmacological evidence implicates trans-cinnamic acid as a feedback modulator of the expression and enzymatic activity of the first enzyme in the phenylpropanoid pathway, L-phenylalanine ammonia-lyase (PAL). To test this hypothesis independently of methods that utilize potentially non-specific inhibitors, we generated transgenic tobacco lines with altered activity levels of the second enzyme ...

A novel enzyme immobilization approach was used to generate mesoporous enzymes-silica composite microparticles by co-entrapping gelatinized starch and cross-linked phenylalanine ammonia lyase (PAL) aggregates (CLEAs) containing gelatinized starch into biomemitic silica and subsequently removing the starch by α-amylase treatment. During the preparation process, the gelatinzed starch served as a ...

Systemic acquired resistance (SAR) is an inducible defence mechanism which plays a central role in protecting plants from microbial pathogen attack. Guided by bioassays, a new chemical inducer of SAR was isolated from the extracts of Strobilanthes cusia and identified to be 3-acetonyl-3-hydroxyoxindole (AHO), a derivative of isatin. Tobacco plants treated with AHO exhibited enhanced resistance ...