Construção de cassetes de expressão para silenciamento de genes da biossíntese de ácidos graxos em soja via RNA de interferência

• Ano de defesa: 2007
• Autor(a) principal: Sousa, Cassiana Severiano de
• Orientador(a): Moreira, Maurílio Alves
• Banca de defesa: Ribon, Andréa de Oliveira Barros , Lima, Andréia Barcelos Passos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Bioquímica Agrícola
• Departamento: Bioquímica e Biologia molecular de plantas; Bioquímica e Biologia molecular animal
• País: BR
• Palavras-chave em Português: Silenciamento gênico; Ácidos graxos; Soja; RNA de interferência; Engenharia genética vegetal; Regulação da expressão gênica; Clonagem molecular
• Palavras-chave em Inglês: Gene silencing; Fatty acids; Soybean; RNA interference
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/2467

The soybean oil is composed in majority by unsaturated fatty acids. The poliunsaturated fatty acids (linolenic and linoleic acids), monounsaturated (oleic acid) and saturated (palmitic and estearic acids) correspond, on average, to 61%, 25% e 15%, respectively. Alterations in the relative proportions of fatty acids may be reached through genetic modification of the expression of key enzymes in the polinunsaturated fatty acids biosynthesis, through genetic transformation of plants by gene silencing. Among these enzymes are desaturases, phosphotransferases and acyltransferases. Modificating the expression of these enzymes is possible to obtain oils with lower content of linolenic acid, increased content of oleic acid and, consequently, higher oxidative stability. The objectives of this work were to isolate the fragments of the soybean oleoil desaturase gene, 1,2-diacylglycerol cholinephosphostransferase gene and lisophasphatidilcholine acyltransferase gene and to construct expression cassettes for silencing, by RNA interference, these three genes in soybean seeds. Fragments of the three genes were isolated and subcloned in sense and antisense in the vector pKANNIBAL and the constructions were transferred to the binary vector pCAMBIA 3301. Four expression cassettes for gene silencing were obtained. Two for the oleoil desaturase, one for the 1,2-diacylglycerol cholinephosphotransferase and one for the lisofosfatidilcholine acyltransferase. There were obtained three cassettes for gene silencing driven by the 35SCaMV promoter, and one cassette for the desaturase gene with the gene promoter of the α subunit of soybean storage protein β - conglycinine.