Resumo

LUNA-RODRIGUEZ, Mauricio; GONZALEZ-OVIEDO, Nelly Abigail; RIVERA-FERNANDEZ, Andrés  e  FLORES-DE LA ROSA, Felipe Roberto. Detection of the xyl3 gene in strains of Fusarium oxysporum f. sp. vanillae. Rev. Mex. Cienc. Agríc [online]. 2023, vol.14, n.6, e2711.  Epub 30-Out-2023. ISSN 2007-0934.  https://doi.org/10.29312/remexca.v14i6.2711.

The mechanisms of Fusarium oxysporum related to the degradation of structural components of the root, such as xylan, are very important since the colonization of this organ is a key piece in the establishment of the disease. The present study focused on detecting the gene coding for the xylanase xyl3 enzyme in strains of F. oxysporum f. sp. vanillae and searching for homologues to this gene in sequences of other formae speciales and species of the Fusarium genus, in order to determine the phylogenetic relationships between xylanases within the F. oxysporum species complex, as well as to search for evidence of natural selection. The results indicated that, of the nine strains evaluated, only three had a copy of the xyl3 gene. The phylogeny showed eight clades, where clade 3 was consistent with the classification of xyl3, while the other types of xylanases were grouped in clade 2. The natural selection test showed no evidence of positive selection within the phylogeny, suggesting that the neutral mutation is responsible for the diversity in the xylanase gene among the F. oxysporum species complex, leading to the proposal that the gene does not appear to have changed with colonization of new hosts.

Palavras-chave : mutations; positive selection; xylanase gene.