Comparação do padrão de expressão gênica de plantas de cana-de-açúcar tolerantes e sensíveis à deficiência hídrica
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Data
2008-07-18
Autores
Rodrigues, Fabiana Aparecida [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A seca é o principal estresse abiótico que afeta a produtividade das plantas. Para detectar os genes expressos sob condições de deficiência hídrica foi desenvolvido um estudo de expressão gênica usando plantas de cana-de-açúcar tolerantes (cv. SP83-5073) e sensíveis (cv. SP90-1638) à seca. A metodologia de macroarranjos de DNA foi empregada para monitorar a expressão gênica de 3.575 clones de folhas de cana-de-açúcar e os resultados foram confirmados por PCR quantitativo. Na cultivar tolerante 165 genes foram identificados em resposta ao déficit hídrico severo, em contraste à cultivar sensível, na qual um maior número de genes (n = 432) foi diferencialmente expresso ao longo do tratamento de deficiência hídrica. A cultivar tolerante ativou um menor número de genes em função do déficit hídrico aplicado. No entanto, 94% destes genes foram induzidos, enquanto na cultivar sensível 45% dos genes diferencialmente expressos foram reprimidos sob condições de deficiência hídrica. Comparando os perfis de expressão identificados em cada planta verifica-se que aproximadamente 55% dos genes expressos na cultivar tolerante também foram comuns à cultivar sensível, a maioria exibindo um perfil de expressão muito similar entre os genes induzidos. A classificação funcional dos genes foi realizada com base no papel exercido pela proteína no metabolismo celular, e mostrou que importantes vias metabólicas relacionadas ao déficit hídrico foram reprimidas na resposta das plantas sensíveis à seca. Além disso, 50% dos transcritos identificados em cada cultivar representam novos genes, os quais não estão descritos nos bancos de dados ou cuja função ainda não foi caracterizada
Drought is a major abiotic stress that affects the plant productivity. To detect expressed genes under drought conditions, a gene expression study using tolerant (SP83-5073) and sensitive (SP90-1638) sugarcane plants was performed. Macroarray methodology was used to monitor the gene expression profile of the 3,575 cDNA clones from sugarcane leaves and the results were confirmed by real time PCR analysis. For the tolerant cultivar 165 genes were identified in response to severe water stress, contrasting with sensitive cultivar, in which a higher number of genes (n = 432) were responsive to the stress-treatment. Tolerant cultivar expressed a few genes in stress conditions. However 94% of them were induced, while for sensitive cultivar 45% of the differentially expressed genes were down-regulated under water stress conditions. Comparing the gene expression profiles identified in each cultivar, it is possible to verify that 55% of the expressed genes in tolerant cultivar were also observed in sensitive cultivar, the majority showing a very similar gene expression pattern. Functional gene classification was performed according to roles in cellular metabolism, and showed that important drought-pathways were repressed in sensitive plants response. Besides, 50% of the identified transcripts in each cultivar represent novel genes, which were not described in databases or whose functions were not characterized yet
Drought is a major abiotic stress that affects the plant productivity. To detect expressed genes under drought conditions, a gene expression study using tolerant (SP83-5073) and sensitive (SP90-1638) sugarcane plants was performed. Macroarray methodology was used to monitor the gene expression profile of the 3,575 cDNA clones from sugarcane leaves and the results were confirmed by real time PCR analysis. For the tolerant cultivar 165 genes were identified in response to severe water stress, contrasting with sensitive cultivar, in which a higher number of genes (n = 432) were responsive to the stress-treatment. Tolerant cultivar expressed a few genes in stress conditions. However 94% of them were induced, while for sensitive cultivar 45% of the differentially expressed genes were down-regulated under water stress conditions. Comparing the gene expression profiles identified in each cultivar, it is possible to verify that 55% of the expressed genes in tolerant cultivar were also observed in sensitive cultivar, the majority showing a very similar gene expression pattern. Functional gene classification was performed according to roles in cellular metabolism, and showed that important drought-pathways were repressed in sensitive plants response. Besides, 50% of the identified transcripts in each cultivar represent novel genes, which were not described in databases or whose functions were not characterized yet
Descrição
Palavras-chave
Cana-de-açúcar, Microarranjos de DNA, Déficit hídrico, Transcriptoma, water deficit, Transcriptome, Macroarray
Como citar
RODRIGUES, Fabiana Aparecida. Comparação do padrão de expressão gênica de plantas de cana-de-açúcar tolerantes e sensíveis à deficiência hídrica. 2008. xv, 104 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 2008.