title: Dark-induced accumulation of a basic pathogenesis-related (PR-1) transcript and a light requirement for its induction by ethylene.
abstract: A gene encoding a basic-type pathogenesis-related protein from Nicotiana tabacum (prb-1b) was cloned, sequenced and characterized. It contains an open reading frame of 179 amino acids that is ca. 65% homologous with the acidic PR-1 class of pathogenesis-related proteins and 87% homologous with a different basic-type PR-1 gene. In the light, physiological levels of ethylene rapidly (1 h) induced basic, but not acidic-type, PR-1 transcript. Additional elicitors acting via ethylene, such as alpha-aminobutyric acid, were shown to induce basic- and acidic-type PR-1 transcript accumulation in a light-dependent manner. In contrast, xylanase, an ethylene-independent elicitor, induced transcript accumulation of basic- and acidic-type PR-1 in a light-independent manner. Dark-induced accumulation of basic PR-1 transcript occurred at night in greenhouse-grown plants and, to a greater extent, in continuously dark-treated plants. The novel dark regulation may point to additional nonpathogenesis-related roles for these genes in plant-environment interactions.
authors.affiliation: Department of Plant Genetics, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Eyal
authors.forename: O
authors.initials: O
authors.lastname: Sagee
authors.forename: R
authors.initials: R
authors.lastname: Fluhr
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004247:DNA; D003624:Darkness; D005030:Ethylenes / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000528:radiation effects; D008027:Light; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction; D014158:Transcription, Genetic
chemical_list: D005030:Ethylenes; D010940:Plant Proteins; C053376:pathogenesis-related proteins, plant; D004247:DNA; C036216:ethylene