Exploração do banco de dados CafEST em busca de prováveis genes de Coffea arabica envolvidos na biossíntese de fenilpropanóides
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2007
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Resumo
Compostos naturais denominados fenilpropanóides apresentam funções na defesa vegetal, desempenhando papéis tanto na defesa pré-existente quanto na defesa induzida local e sistêmica em resposta ao ataque de patógenos. Prováveis genes que codificam para cada uma das 21 enzimas-chave envolvidas na biossíntese de fenilpropanóides em C. arabica foram identificados dentro do banco de dados brasileiro de genoma funcional de café (CafEST). De um total de 3559 ESTs selecionadas , 101 ESTs provavelmente representam a classe fenilalanina-amônia-liase (PAL). PAL catalisa a reação de desaminação de fenilalanina para gerar ácido cinâmico, dando início à rota dos fenilpropanoides. Os maiores números de ESTs, 521 e 490, foram encontrados representando as classes das enzimas cinamato 4-hidroxilase (C4H) e isoflavona O-metil-transferase (IOMT), respectivamente. Os menores números de ESTs encontrados, 21 e 36, representam as classes das enzimas chalcona isomerase (CHI) and cafeoil coenzima A O-metil-transferase (CCOMT). Análise detalhada dos 11 clusters de ESTs do tipo PAL revelou que seqüências de aminoácidos deduzidas compartilham alta similaridade (84-100%) com proteínas PAL isoladas das plantas Coffea canephora, Ipomoea nil, Catharanthus roseus, Jatropha curcas e Ulmus pumila. Além disso, a presença de uma possível ORF completa foi revelada. Ainda foi possível observar que das 101 ESTs identificadas para a classe PAL, 38 foram expressas em folhas de C. arabica sob diferentes condições, sendo a maioria encontrada em folhas de ramos plagiotrópicas de plantas adultas não tratadas com Bion. As ESTs do tipo PAL expressas em folhas estão presentes em 5 dos 6 contigs e em 2 singlets. A análise de ‘neighbour-joining’ gerou um filograma que agrupou cinco seqüências oriundas de contigs do tipo PAL de C. arabica em dois grupos maiores. A presença de possíveis membros de todas as enzimas-chave envolvidas na biossíntese de fenilpropanóides no genoma de C. arabica ainda não tinha sido relatada. Os prováveis genes identificados neste trabalho são candidatos para análises in silico e experimentais sobre o perfil de expressão. A elucidação da via de biossíntese de fenilpropanóides no metabolismo de café pode gerar impactos sobre o desfecho da resistência a doenças nesta cultura economicamente importante, levando a ganhos positivos sobre o agronegócio cafeeiro.
Phenylpropanoid natural compounds encompass functions in plant defense, playing roles in preformed or inducible as well as local and systemic defense in response to pathogen attack. Putative genes encoding all of the 21 key enzymes involved in phenylpropanoid biosynthesis in Coffea arabica were identified within the Brazilian coffee functional genome database (CafEST). From a total of 3559 ESTs-reads present in C. arabica, 101 ESTs were found representing the phenylalanine ammonia-lyase (PAL) enzyme. PAL catalyzes the deamination reaction of phenylalanine to give cinnamic acid, which is the first step of the phenylpropanoid pathway. The higher numbers of ESTs, 521 and 490, were found representing the Cinnamate 4-hydroxylase (C4H) and Isoflavone O-methyl-transferase (IOMT) enzymes, respectively. The lower numbers of ESTs, 21 and 36, were found representing the Chalcone isomerase (CHI) and Caffeoyl coenzyme A O-methyl-transferase (CCOMT) enzymes. Detailed analysis of the 11 PAL-like-EST-clusters revealed that deduced amino acid sequences share high similarities (84-100%) with Pal proteins from Coffea canephora, Ipomoea nil, Catharanthus roseus, Jatropha curcas e Ulmus pumila plants. In addition, the presence of a putative complete PAL-like ORF. It was also possible to observe that of the 101 identified PAL-ESTs 38 were expressed under different conditions, being that the majority was found in plagiotropic leaves from adult plants untreated with Bion. The PAL-ESTs that were expressed in leaves were grouped within 5 of the 6 contigs and 2 singlets. A neighbour-joining analises of aligned amino acid sequences generated a phylogram which grouped 5 PAL-like sequences from C. arabica contigs into two major groups. The presence of all members of key enzymes involved in phenylpropanoid biosynthesis in C. arabica genome has not yet been reported. The putative genes here identified are candidate to in silico and experimental expression profiles analyses. Elucidation of the phenylpropanoid pathway in coffee metabolism may strongly impact the outcome of the disease resistance in this economically important crop, leading to many positive gains on the coffee agribusiness.
Phenylpropanoid natural compounds encompass functions in plant defense, playing roles in preformed or inducible as well as local and systemic defense in response to pathogen attack. Putative genes encoding all of the 21 key enzymes involved in phenylpropanoid biosynthesis in Coffea arabica were identified within the Brazilian coffee functional genome database (CafEST). From a total of 3559 ESTs-reads present in C. arabica, 101 ESTs were found representing the phenylalanine ammonia-lyase (PAL) enzyme. PAL catalyzes the deamination reaction of phenylalanine to give cinnamic acid, which is the first step of the phenylpropanoid pathway. The higher numbers of ESTs, 521 and 490, were found representing the Cinnamate 4-hydroxylase (C4H) and Isoflavone O-methyl-transferase (IOMT) enzymes, respectively. The lower numbers of ESTs, 21 and 36, were found representing the Chalcone isomerase (CHI) and Caffeoyl coenzyme A O-methyl-transferase (CCOMT) enzymes. Detailed analysis of the 11 PAL-like-EST-clusters revealed that deduced amino acid sequences share high similarities (84-100%) with Pal proteins from Coffea canephora, Ipomoea nil, Catharanthus roseus, Jatropha curcas e Ulmus pumila plants. In addition, the presence of a putative complete PAL-like ORF. It was also possible to observe that of the 101 identified PAL-ESTs 38 were expressed under different conditions, being that the majority was found in plagiotropic leaves from adult plants untreated with Bion. The PAL-ESTs that were expressed in leaves were grouped within 5 of the 6 contigs and 2 singlets. A neighbour-joining analises of aligned amino acid sequences generated a phylogram which grouped 5 PAL-like sequences from C. arabica contigs into two major groups. The presence of all members of key enzymes involved in phenylpropanoid biosynthesis in C. arabica genome has not yet been reported. The putative genes here identified are candidate to in silico and experimental expression profiles analyses. Elucidation of the phenylpropanoid pathway in coffee metabolism may strongly impact the outcome of the disease resistance in this economically important crop, leading to many positive gains on the coffee agribusiness.
Descrição
Trabalho apresentado no Simpósio de Pesquisa dos Cafés do Brasil (5. : 2007 : Águas de Lindóia, SP). Anais. Brasília, D.F. : Embrapa Café, 2007.
Palavras-chave
Genoma Resistência induzida DNA PAL Parasitos, Genome Induced resistance DNA PAL Parasites
Citação
Campos, Magnólia A.; Medeiros, Fernanda C.L.; Pereira, Lívia M.; Resende, Mário Lúcio V.; Silva, Marília S.; Mehta, Angela; Sá, Maria Fátima Grossi de. Exploração do banco de dados CafEST em busca de prováveis genes de Coffea arabica envolvidos na biossíntese de fenilpropanóides. In: Simpósio de Pesquisa dos Cafés do Brasil (5. : Águas de Lindóia, SP : 2007). Anais. Brasília, D.F. : Embrapa - Café, 2007. (1 CD-ROM), 5p.