An Arabidopsis mutant tolerant to lethal ultraviolet-B levels shows constitutively elevated accumulation of flavonoids and other phenolics.

The isolation and characterization of mutants hypersensitive to ultraviolet (UV) radiation has been a powerful tool to learn about the mechanisms that protect plants against UV-induced damage. To increase our understanding of the various mechanisms of defense against UVB radiation, we searched for mutations that would increase the level of tolerance of Arabidopsis plants to UV radiation. We describe a single gene dominant mutation (uvt1) that leads to a remarkable tolerance to UVB radiation conditions that would kill wild-type plants.

Differential wound activation of members of the phenylalanine ammonia-lyase and 4-coumarate:CoA ligase gene families in various organs of parsley plants.

We analyzed the developmental regulation and the activation by wounding of several stress-related genes in various parsley organs. The genes encode phenylalanine ammonia-lyase (PAL) and 4-coumarate:CoA ligase (4CL), two enzymes of general phenylpropanoid metabolism; a flavonoid specific enzyme, chalcone synthase (CHS); a furanocoumarin specific enzyme, bergaptol O-methyltransferase (BMT); and a pathogenesis-related protein (PR 1). All genes or gene families exhibited high levels of expression in roots and during certain stages of leaf development.

Active beta-globin gene transcription occurs in methylated, DNase I-resistant chromatin of nonerythroid chicken cells.

We report active, inappropriate transcription of the chicken beta A-globin gene in normal fibroblasts, cultured MSB cells, and brain. We were unable to detect ovalbumin gene transcription in these same tissues. Most of the globin gene transcripts were found to be truncated near the beginning of the gene, suggesting the existence of a premature termination process that is preferentially active under conditions of inappropriate transcription.