The psoralen compounds, xanthotoxin and 4,5', 8-trimethylpsoralen, when activated, increased phenylalanine ammonia lyase (PAL) activity and the synthesis of pisatin in excised pea pods. Pods presoaked 1 hr with 4,5',8-trimethylpsoralen and then irradiated 4 minutes with 366 nanometer ultraviolet light had twice as much PAL activity 3 hours after irradiation and 12 times as much PAL activity 20 ...

3H-l-Phenylalanine is incorporated into a range of phenylpropanoid compounds when fed to tobacco cell cultures. A significant proportion of (3)H-trans-cinnamic acid formed from (3)H-l-phenylalanine did not equilibrate with exogenous trans-cinnamic acid and therefore may be rapidly channeled through the cinnamate 4-hydroxylase (C4H) reaction to 4-coumaric acid. Such compartmentalization of trans...

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...

Plants develop a plethora of defense strategies during their acclimation and interactions with various environmental stresses. Secondary metabolites play pivotal role in the processes stress acclimation, therefore deciphering relevant responses exchange interpretation underlying molecular mechanisms that may contribute to improved adaptability efficacy. In current study, tomato plants were expo...

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 ...

A cDNA clone for phenylalanine ammonia-lyase (PAL) induced in wounded sweet potato (Ipomoea batatas Lam.) root was obtained by immunoscreening a cDNA library. The protein produced in Escherichia coli cells containing the plasmid pPAL02 was indistinguishable from sweet potato PAL as judged by Ouchterlony double diffusion assays. The M(r) of its subunit was 77,000. The cells converted [(14)C]-l-p...

The mRNAs encoding two enzymes of phenylpropanoid metabolism, phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) and 4-coumarate:CoA ligase (4CL; EC 6.2.1.12), were induced in cultured parsley cells (Petroselinum hortense) either by irradiation with UV light or by treatment with elicitor, a cell-wall fraction of the fungus Phytophthora megasperma f. sp. glycinea. Two-dimensional gel electrophoresis ...

A tobacco (Nicotiana tabacum L. cv Samsun NN) cDNA clone coding the enzyme phenylalanine ammonia-lyase (PAL) was isolated from a cDNA library made from polyadenylated RNA purified from tobacco mosaic virus (TMV)-infected leaves. Southern analysis indicated that, in tobacco, PAL is encoded by a small family of two to four unclustered genes. Northern analysis showed that PAL genes are weakly expr...

Abstract Phenolic acids are the major secondary metabolites and significant bioactive constituents of medicinal plant Salvia miltiorrhiza. Many enzyme-encoding genes transcription factors involved in biosynthesis phenolic have been identified, but underlying post-translational regulatory mechanisms poorly understood. Here, we demonstrate that S. miltiorrhiza Kelch repeat F-box protein SmKFB5 ph...

Banana blossoms are rich in fiber and nutrients a popular plant-based, vegan alternative to fish. However undesirable browning, usually visible at the peduncle cut-end, negatively impacts consumer acceptability of banana blossoms. The aim this work was develop safe alternatives prevent browning First, activities primary enzymes associated with tissue i.e., polyphenol oxidase (PPO), peroxidase (...