Identificação e caracterização de proteinas e genes expressos diferencialmente durante o desenvolvimento do embrião zigotico de Araucaria angustifolia

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

Arauearia angustifolia, the only native conifer in Brazil, covered the States of Paraná (40%), Santa Catarina (31 %) and Rio Grande do Sul (25%). Sparse patches were also found in areas with elevated altitudes, in the States of São Paulo (3%), Minas Gerais and Rio de Janeiro (1 %). The A. angustifolia wood was, for a long time, one of the most important exportation products in Brazil. In the present days, the A. angustifolia is at risk of extinction, and the remaining areas correspond to 4.3% ofthe original. The A. angustifolia embryo development is divided in the following stages: (1) early globular stage, (2) late globular stage, (3) torpedo stage, (4) cotiledonar and (5) mature stage. The development of the A. angustifolia embryo differs in some morphologic aspects from other conifers. Therefore, it is interesting to studyembryo development in A. angustifolia. In Chapter 1,"Characterization of the major storage proteins in A. angustifolia", the characterization of the major storage proteins of A. angustifolia was described. These proteins are soluble in solutions with low-salt concentration (NaCl 0.25 M). They have apparent molecular weights around 20-21 kDa and 28 kDa, and there are no evidences of bisulfide bonds. All these characteristics diverged from those described for storage proteins in other conifers, and indicated that the major storage proteins of A. angustifolia are 7S vicilin-like. In Chapter 2, "ldentification of differential expressed genes during development of the zygotic embryo in A. angustifolia", the mRNA differential display technique was used to identify genes differentially expressed in the developing embryo, globular, cotiledonar and mature stages, and in the megagametophyte of mature seed. A total of 315 differentially expressed cDNAs were isolated. From these, 189 cDNAs had their differential expression confirmed and 39 were cloned and submitted to sequencing. Nine cDNAs showed similarity with GenBank sequences. In Chapter 3, "lsolation and characterization of the full length sequences of J6G-63, J5G-26 and J5G-20 cDNAs", the isolation of full-Iength cDNA sequences of the 7S vicilin-like gene (J6G-63 cDNA), the lipocalin gene (J5G-20 cDNA) and the araCAFl transcription factor gene (J5G-26) is described

ASSUNTO(S)

conifera sementes pinheiro-do-parana - embrião

ACESSO AO ARTIGO

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