Comparative analysis of pathogenic and nonpathogenic Fusarium oxysporum populations associated with banana on a farm in Minas Gerais, Brazil

Autor: Pauline Deltour, Soraya de Carvalho França, Lisa Heyman, Monica Höfte, Olinto Liparini Pereira
Rok vydání: 2017
Předmět:
Zdroj: Plant Pathology. 67:707-718
ISSN: 0032-0862
DOI: 10.1111/ppa.12757
Popis: Fusarium wilt is one of the most devastating diseases on banana. The causal agent, Fusarium oxysporum f. sp. cubense (Foc) is genetically diverse and its origin and virulence are poorly understood. In this study, pathogenic Foc isolates and non-pathogenic F. oxysporum isolates from Minas Gerais in Brazil were compared using EF-1α and IGS sequences. This allowed us to examine the origin and evolutionary potential of Foc in a country outside the region of origin of the banana plant. Two different sequence types were found among Foc isolates. One sequence type appeared to be of local origin since it was identical to the sequence type of the largest group of non-pathogenic isolates. To explore if the ‘local’ Foc isolates had acquired pathogenicity either independently through co-evolution with the host, or through horizontal gene transfer (HGT) of pathogenicity genes from other, probably introduced, Foc isolates, the presence and sequence of putative SIX effector genes were analyzed. Homologues of SIX1, SIX3 and SIX8 were found. SIX1 sequences were identical and exclusively found in all pathogenic isolates, while variable ratios of sequences of multi-copy gene SIX8 were found among non-pathogenic and different pathogenic isolates. This observation supports the HGT hypothesis. Horizontal transfer of genes between isolates of F. oxysporum has important implications on the development of reliable diagnostic tools and effective control measures. Full genome sequencing is required to confirm HGT and to further unravel the virulence mechanisms of forma specialis cubense. This article is protected by copyright. All rights reserved.
Databáze: OpenAIRE
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