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Publicação
Respostas celulares e moleculares em interacções hospedeiras e não hospedeiras cafeeiro-ferrugem (Hemileia vastatrix e Uromyces vignae)
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Resumo(s)
Cellular and molecular characterization of resistance to H. vastatrix in coffee lines HDT 832/2 and
Sarchimor, was conducted using the non-host resistance model coffee-Uromyces vignae
(cow pea rust) for comparison. In both lines, H. vastatrix ceased growth more frequently at the
penetration hypha stage, forming few haustoria, inducing hypersensitive reaction (HR), phenol
accumulation and haustorium encasement with calose. U. vignae growth was more restricted in
HDT 832/2, but failed to form haustoria in both lines, while inducing HR and phenol accumulation.
The expression of genes involved in mechanisms of recognition, signaling and defence (rlk, wrky1,
pal, chs, 13-lox, gt, pr1b and pr10) was monitored by real time PCR. Both in the host and non-host
interactions the expression profile of rlk and wrky1 suggests that the recognition of the fungus and
signaling occur during the formation of appressoria over stomata and the differentiation of the first
post-penetration infection stages. The first activation peak of 13-lox coincided with the onset of cell
death detection. pr1b exhibited high expression levels in the host interaction, being poorly activated in
the non-host interaction. These results suggest that both JA and SA pathways may coexist, although
SA pathway seams to prevail in the host interaction.
Descrição
Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia
Palavras-chave
coffee coffee leaf rust host resistance non-host resistance hypersensitive reaction gene expression cafeeiro ferrugem alaranjada resistência hospedeira resistência não-hospedeira reacção de hipersensibilidade expressão génica