Avaliação da expressão de transportadores de amónio em pereira 'Rocha' enxertada em marmeleiro BA29 em resposta á fertilização azotada

• Autor(a) principal: Oliveira, Cristina Moniz
• Data de Publicação: 2009
• Outros Autores: Mota, Mariana, Neto, Cláudia
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.5/2374
• topic: Pyrus communis; nitrogen deficiency; fertigation; AMT1; deficiência de azoto; fertirrigação

To clarify the role of ammonium transporters in N nutrition of ‘Rocha’ pear trees grafted on ‘BA29’ quince, genes encoding ammonium transporters (AMT1) expressed in the roots were identified under no N supply, and their diversity and regulation upon N application after fruit set was investigated. In this study, thin roots of ‘Rocha’pear/’BA29’ quince were sampled in a plot without N fertilization and four distinct genetic sequences were isolated by RT-PCR (C3, C5, C6, C12), which showed high homology with AMT1 transporters. The study of the relative abundance of each sequence showed highest abundance of C3, homologue with one AMT1 transporter, already characterized and strongly expressed in N deficiency conditions. In the fertilized plot, in roots harvested two hours after fertigation with 40 kg N/ha, this pattern changed, and C3 was not the most abundant sequence. These results suggest that ammonium transporters are expressed immediately after fertigation and that the expression of these genes is regulated by fertilization, with reduction of the expression of the AMT1 gene that might be related to conditions of N deficiency. These results can be used to improve the decision making regarding the amounts of N fertilizers to be applied, and thus to improve the efficiency of N use.