Vias de sinalização mediadas por ácido salicílico e metil-jasmonato e papel de GmbZIP89 em resposta à infecção por Phakopsora pachyrhizi em genótipos contrastantes de soja
Uma resposta de defesa efetiva contra patógenos depende de uma grande reprogramação gênica, regulada principalmente por fatores de transcrição. Várias famílias de fatores de transcrição estão ligadas à resposta da planta ao ataque de patógenos e entre elas está a família bZIP (Basic Leucine Zipper)....
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Universidade Federal de Viçosa
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|Citação:||BARROS, Vanessa de Almeida. Vias de sinalização mediadas por ácido salicílico e metil-jasmonato e papel de GmbZIP89 em resposta à infecção por Phakopsora pachyrhizi em genótipos contrastantes de soja. 2016. 32f. Dissertação (Mestrado em Bioquímica Aplicada) - Universidade Federal de Viçosa, Viçosa. 2016.|
|Resumo inglês:||An effective defense response against pathogens depends on a wide genetic reprogramming, regulated mainly by transcription factors. Several transcription factors’ families are linked to the plant’s response to the attack of pathogens and among them there is the bZIP family (Basic Leucine Zipper). The transfactor GmbZIP89 is differentially expressed during a Phakopsora pachyrhizi, the biotrophic fungus responsible for causing asian rust infection on soybean. This factor is highly similar to G/HBF-1 responsive to biotic stress and GmbZIP105 responsive to P. pachyrhizi. This suggests that GmbZIP89 could be involved in the response to asian rust. This project aims to investigate the role of GmbZIP89 and hormone signaling during a P. pachyrhizi infection on soybean. We showed that at the beginning of the infection there is a response through jasmonate (JA) and ethylene (ET) followed by the signaling through salicylic acid (SA) and during later stages of the infection there is and induction of response through JA. We suppose that TGA2 and ORA59 are involved on JA/SA crosstalk during the infection. SA might induce TGA2’s expression and inhibit ORA59’s expression compromising the induction of genes, which are responsive to JA. We showed that during early and later infection stages, P. pachyrhizi mimics a necrotrophic pathogen’s attack, eliciting JA mediated responses. Effectors secreted by the fungus probably result in the transcriptional regulation of JAZ1 and COI1, mediating the activation of a response through JA. These effectors also seem to modulate GmbZIP89 expression, which might act in the activation of genes that are responsive to JA or in the transcriptional repression of SA-responsive genes, in both cases compromising the induction of the SA-dependent defense. The inhibition of the SA signaling guarantees a great adaptive advantage to the fungus because it ceases cell death arising from SA pathway signaling. The maintenance of foliar tissue integrity is crucial to biotrophic pathogens that require live tissue to obtain nutrients and thus allow P. pachyrhizi colonization and spread.|