Differential Accumulation of Plant Defense Gene Transcripts in a Compatible and an Incompatible Plant-Pathogen Interaction
Autor: | John N. Bell, J.A. Bailey, V. P. M. Wingate, Thomas B. Ryder, Christopher J. Lamb |
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Rok vydání: | 1986 |
Předmět: |
Chalcone synthase
Transcription Genetic Genes Fungal Phenylalanine ammonia-lyase Transcription (biology) RNA Messenger Molecular Biology Gene chemistry.chemical_classification Plants Medicinal Base Sequence biology Phenylpropanoid Colletotrichum lindemuthianum Phytoalexin Fungi Nucleic Acid Hybridization food and beverages RNA Fabaceae DNA Cell Biology Plants biology.organism_classification Cell biology Genes chemistry Biochemistry biology.protein Research Article |
Zdroj: | Molecular and Cellular Biology. 6:1615-1623 |
ISSN: | 1098-5549 |
Popis: | Phenylalanine ammonia-lyase and chalcone synthase catalyze the first reaction of phenylpropanoid biosynthesis and the first reaction of a branch pathway specific for flavonoid-isoflavonoid biosynthesis, respectively. These enzymes are key control elements in the synthesis of kievitone, phaseollin, and related isoflavonoid-derived phytoalexins. RNA blot hybridization with 32P-labeled cDNA sequences was used to demonstrate marked accumulation of phenylalanine ammonia-lyase and chalcone synthase mRNAs in excision-wounded hypocotyls of Phaseolus vulgaris L. (dwarf French bean) and during race-cultivar-specific interactions between hypocotyls of P. vulgaris and the partially biotrophic fungus Colletotrichum lindemuthianum, the causal agent of anthracnose. In an incompatible interaction (host resistant), early concomitant accumulation of phenylalanine ammonia-lyase and chalcone synthase mRNAs, localized mainly but not entirely in tissue adjacent to the site of infection, was observed prior to the onset of phytoalexin accumulation and expression of localized, hypersensitive resistance. In contrast, in a compatible interaction (host susceptible) there was no early accumulation of these transcripts; instead, there was a delayed widespread response associated with phytoalexin accumulation during attempted lesion limitation. Two-dimensional gel electrophoresis of [35S]methionine-labeled polypeptides synthesized in vitro by translation of isolated polysomal RNA demonstrated stimulation of the synthesis of characteristic sets of phenylalanine ammonia-lyase and chalcone synthase isopolypeptides in directly infected tissue and distant, hitherto uninfected tissue in both compatible and incompatible interactions. Our data show that specific accumulation of plant defense gene transcripts is a key early component in the sequence of events leading to expression of defense responses in wounded tissue and in infected tissue during race-cultivar-specific interactions and that an elicitation signal is transmitted intercellularly in response to infection. |
Databáze: | OpenAIRE |
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