Publicação
Identification of PAL and CHS genes in Pinus pinaster and its expression analysis after eliciting by Botrytis cinerea
| Resumo: | Pinus pinaster Ait. is the main forest species in Portugal, assuming vital economical importance due to the substantial market value of some of its derivatives, coupled with good adaptability to most of the portuguese territory. Recently, attack of young seedlings by the pathogenic fungi Botrytis cinerea, has led to deficient self-regeneration of portuguese pine forests, coupled with the devastation of pine nurseries. To understand the metabolic and molecular responses of P. pinaster against B. cinerea, we identified genes encoding for key enzymes of the phenylpropanoid metabolism, namely phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS). PAL catalyses L-Phenyalanine into trans-cinnamic acid, which is the foremost intermediary in phenolics biosynthesis. It exists in plants as a gene family, with several isoforms already discovered. The CHS superfamily comprises extremely homologous but catabolically different enzymes responsible for the synthesis of various secondary metabolites, including flavonoids and stilbene. Chalcone synthase has been the evolutionary basis for this diversity, and plays a pivotal role in metabolism, deriving the phenylpropanoid pathway into the synthesis of chalcone. Gene isolation was possible through screening of a P. pinaster cDNA library with an heterologous probe for CHS, and the use of degenerate priming for conserved PAL sequences, followed by screening of the cDNA library with an homologous probe. We were able to isolate three different genes encoding for CHS and two different genes for PAL. CHS genes presented an open reading frame of approximately 1.1 kbp, encoding for an estimated 39 kDa protein, while PAL genes indicated an estimated 1.6 kbp ORF and 57 kDA protein. Multiple sequence alignment using clustalW and philogenetic inference placed the CHS sequences well within coniphers, while PAL genes were the first completely sequenced genes reported in coniphers. Studies evaluating the expression of these genes during the incompatible response to pathogen attack are now underway. |
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| Autores principais: | Azevedo, Herlânder |
| Outros Autores: | Neto, T. Lino; Tavares, R. M. |
| Ano: | 2003 |
| País: | Portugal |
| Tipo de documento: | póster em conferência |
| Tipo de acesso: | acesso restrito |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Pinus pinaster Ait. is the main forest species in Portugal, assuming vital economical importance due to the substantial market value of some of its derivatives, coupled with good adaptability to most of the portuguese territory. Recently, attack of young seedlings by the pathogenic fungi Botrytis cinerea, has led to deficient self-regeneration of portuguese pine forests, coupled with the devastation of pine nurseries. To understand the metabolic and molecular responses of P. pinaster against B. cinerea, we identified genes encoding for key enzymes of the phenylpropanoid metabolism, namely phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS). PAL catalyses L-Phenyalanine into trans-cinnamic acid, which is the foremost intermediary in phenolics biosynthesis. It exists in plants as a gene family, with several isoforms already discovered. The CHS superfamily comprises extremely homologous but catabolically different enzymes responsible for the synthesis of various secondary metabolites, including flavonoids and stilbene. Chalcone synthase has been the evolutionary basis for this diversity, and plays a pivotal role in metabolism, deriving the phenylpropanoid pathway into the synthesis of chalcone. Gene isolation was possible through screening of a P. pinaster cDNA library with an heterologous probe for CHS, and the use of degenerate priming for conserved PAL sequences, followed by screening of the cDNA library with an homologous probe. We were able to isolate three different genes encoding for CHS and two different genes for PAL. CHS genes presented an open reading frame of approximately 1.1 kbp, encoding for an estimated 39 kDa protein, while PAL genes indicated an estimated 1.6 kbp ORF and 57 kDA protein. Multiple sequence alignment using clustalW and philogenetic inference placed the CHS sequences well within coniphers, while PAL genes were the first completely sequenced genes reported in coniphers. Studies evaluating the expression of these genes during the incompatible response to pathogen attack are now underway. |
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