Programa de Pós-Graduação em Agronomia

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Navegando Programa de Pós-Graduação em Agronomia por Autor "Abe, Valeria Yukari"

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    Caracterização estrutural e polimorfismo de genes candidatos à efetores de Phakopsora pachyrhizi
    (Universidade Estadual do Norte do Paraná, 2017-03-30) Castanho, Fernanda Machado; Carvalho, Mayra Costa da Cruz Gallo de; https://orcid.org/0000-0002-1559-3828; http://lattes.cnpq.br/2844751503530944; Carvalho, Mayra Costa da Cruz Gallo de; https://orcid.org/0000-0002-1559-3828; http://lattes.cnpq.br/2844751503530944; Zawadzki, Aline Vanessa Sauer; https://orcid.org/0000-0003-3164-9710; Abe, Valeria Yukari; https://orcid.org/0009-0005-3231-6928; http://lattes.cnpq.br/8080855435804141; Carvalho, Sandremir de; http://lattes.cnpq.br/8684697240694261; Matsumoto, Leopoldo Sussumu; https://orcid.org/0000-0001-5102-545X; http://lattes.cnpq.br/0857955043436449
    Soybean rust (ASR), caused by the obligate biotrophic fungus Phakopsora pachyrhizi Syd. & P. Syd., is one of the most destructive diseases affecting soybean (Glycine max). Although six loci for resistance to Phakopsora pachyrhizi (Rpp) have been mapped in soybean, no cultivars are yet completely resistant to the wide diversity of pathogenic races of P. pachyrhizi. During infection, the fungus secretes small proteins designated SSPs (Small Secreted Proteins), which may act as virulence effectors in susceptible hosts or as avirulence (Avr) effectors in resistant hosts. The coevolutionary relationship between soybean and the fungus maintains Avr-R interactions under persistent selective pressure. Characterizing genetic variation in candidate effector genes from P. pachyrhizi therefore improves our understanding of the selective forces driving R-Avr coevolution and can help identify key domains involved in recognition. Recently, 13 gene families or tribes enriched in putative P. pachyrhizi effectors were identified, of which families 1, 2, and 3 were highlighted as the most relevant. In this study, we evaluated the molecular structure, genetic variability, and phylogeny of seven candidate effector genes from families 1 and 3. To investigate evolutionary patterns of polymorphism and signatures of selection, three fungal isolates (FTPY15.1M, LDA13.2M, and L.PF02B07) sampled across different years and geographic regions were analyzed. All candidates shared features typical of known effectors: small size, predicted secretion signal peptides, conserved motifs, and cysteine residues. Family 1 candidates exhibited higher polymorphism, totaling 160 SNPs and 8 non-synonymous substitutions, compared with 48 SNPs and 1 non-synonymous substitution in family 3. Family 1 candidates also displayed greater phylogenetic diversity. Candidate gene 5849 alone resolved isolates into two distinct clusters. Both candidate 5849 and candidate 2238 showed significant evidence of positive selection, particularly within conserved RCR motifs. These findings suggest that both genes function as effectors and that the RCR motifs play an important role in R-mediated recognition.