RESUMO
Appressorium is an infection structure of the phytopathogenic fungus Magnaporthe grisea. Analysis of gene expression profiles of appressorium development provides insight into the molecular basis of pathogenicity and control of this fungal plant disease. A cDNA array representing 2927 unique genes based on a large EST (expressed sequence tag) database of M. grisea strain Y34 was constructed and used to profile the gene expression patterns at mycelium and appressorium maturation stages. Compared with mycelia, 55 up-regulated and 22 down-regulated genes were identified in mature appressoria. Among 77 genes, 16 genes showed no similarity to the genome sequences of M. grisea. A novel homologue of peptidyl-prolyl cis-trans isomerase was found to be expressed at low-level in mature appressoria of M. grisea. The results indicated that the genes such as pyruvate carboxylase, phospholipid metabolism-related protein and glyceraldehyde 3-phosphate dehydrogenase involved in gluconeogenesis, lipid metabolism and glycolysis, showed differential expression in mature appressoria. Furthermore, genes such as PTH11, beta subunit of G protein and SGT1 involved in cell signalling, were expressed differentially in mature appressoria. Northern blot analysis was used to confirm the cDNA array results.
Assuntos
Proteínas Fúngicas/metabolismo , Estruturas Fúngicas/metabolismo , Perfilação da Expressão Gênica/métodos , Magnaporthe/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Proteoma/metabolismo , Proliferação de CélulasRESUMO
The 3' untranslated regions deeply affect many properties of eukaryotic mRNA. In plants, the polyadenine control signals contained in these regions seem to be more variable than of mammals. Three cDNA libraries derived from the leaf, endosperm and stem tissues of rice were sequenced from the 3'-end. Of the 9911 transcripts analyzed, 5723 unique transcripts were identified from the leaf sequences, 2934 from the endosperm and 1254 from the stem. The information entropy and two statistical methods were used to compile a list of rice poly(A) control signals. Based on their distribution, these signals can be roughly grouped into far-upstream element (FUE), near-upstream element (NUE), T-rich region (TRE) and downstream element (DE). The distribution of rice conserved regions is similar to the previous model from Arabidopsis and yeast, with a few differences in word constructions. Interestingly, we also found the word distributions were diverse in the cleavage site of downstream sequences of different rice tissues. The signal bias in downstream sequences may lead mRNA to be differently cleaved in different rice tissues.
Assuntos
Oryza/genética , Sinais de Poliadenilação na Ponta 3' do RNA , RNA de Plantas/genética , Regiões 3' não Traduzidas , Biologia Computacional , DNA Complementar , Etiquetas de Sequências Expressas , Regulação da Expressão Gênica de Plantas , Biblioteca Gênica , Folhas de Planta/genética , Caules de Planta/genética , Processamento Pós-Transcricional do RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Plantas/metabolismo , Sementes/genéticaRESUMO
We obtained 3,372 tentative unique transcripts (TUTs) from a cDNA library of Fusarium oxysporum. A cDNA array with 3,158 TUTs was produced to analyze gene expression profiles in conidial germination. It seems that ras and other signaling genes, e.g., ccg, cooperatively initiate conidial germination in Fusarium by increasing protein synthesis.
