Caracterização in silico de genes da biossíntese de lipídeos e utilização de eixos embrionários e nós-cotiledonares na transformação genética de soja

• Autor(a) principal: Sousa, Cassiana Severiano de
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/312
• topic: Eixos embrionários; Soja; Nós-cotiledonares; Embryonic axes; Soybean; Cotyledonary nodes; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL

The activities of the enzymes oleoyl desaturase, 1,2-diacylglycerol cholinephosphotransferase (CPT) and lysophosphatidylcholine acyltransferase (LPCAT) regulate the biosynthesis of lipids in plants. Thus, a better understanding of the genes encoding these enzymes is important in the genetic manipulation of the soybean oil quality. Therefore, the first chapter presents the in silico characterization of the genes encoding the enzymes CPT and LPCAT in soybean. The second chapter presents an evaluation of the use of embryonic axes and cotyledonary nodes as explants in tissue culture protocols for genetic transformation, via RNA interference, with silencing cassettes of the oleyl desaturase gene. Computer analysis showed that the soybean genome has two genes encoding CPT and two genes encoding LPCAT, with one of these models showing an alternative transcript. Cis-elements in the promoter regions were identified that are responsible for seed-specific expression and also in response to biotic and abiotic stresses. In silico analysis suggested the expression of the genes in different stress conditions, in differentiating somatic embryos, in immature seeds, in root tissue and callus. The amino acid sequence analysis revealed the presence of transmembrane domains and searching for subcellular localization indicated that CPT and LPCAT are located in the endoplasmic reticulum. Since these genes are expressed in seeds, they are possible candidates for genetic manipulation aim the improvement of oil quality. Two soybean transformation protocols were evaluated for the possibility of obtaining soybean oil with greater oxidation stability. The commercial varieties CAC-1 (late cycle) and CD-201 (early cycle) were subjected to infection via Agrobacterium tumefaciens strain KYRT1. The protocol used for the embryonic axis transformation was faster, with less elaborate culture media in relation to composition and a greater number of plants were transferred to the greenhouse, where they remained until the production of pods and seeds. It was possible to perform all stages, from infection to regeneration and acclimatization of plants, for the varieties used with the protocols described.