Luciana Veiga Barbosa

Analysis of the ergosterol biosynthesis pathway cloning, molecular characterization and phylogeny of lanosterol 14α-demethylase (ERG11) gene of Moniliophthora perniciosa

The phytopathogenic fungus Moniliophthora perniciosa (Stahel) Aime & Philips-Mora, causal agent of witches’ broom disease of cocoa, causes countless damage to cocoa production in Brazil. Molecular studies have attempted to identify genes that play important roles in fungal survival and virulence. In this study, sequences deposited in the M. perniciosa Genome Sequencing Project database were analyzed to identify potential biological targets. For the first time, the ergosterol biosynthetic pathway in M. perniciosa was studied and the lanosterol 14α-demethylase gene (ERG11) that encodes the main enzyme of this pathway and is a target for fungicides was cloned, characterized molecularly and its phylogeny analyzed. ERG11 genomic DNA and cDNA were characterized and sequence analysis of the ERG11 protein identified highly conserved domains typical of this enzyme, such as SRS1, SRS4, EXXR and the heme-binding region (HBR). Comparison of the protein sequences and phylogenetic analysis revealed that the M. perniciosa enzyme was most closely related to that of Coprinopsis cinerea.

Diversidade genética de Xylella fastidiosa em regiões produtoras de citros na Bahia

O objetivo deste trabalho foi avaliar, por meio de marcadores SSR, a diversidade genetica de Xylella fastidiosa no Estado da Bahia. Foram estudadas duas das principais regioes produtoras de citros no Estado, o Litoral Norte e o Reconcavo Sul. Para fins comparativos, utilizaram-se dez amostras provenientes do Estado de Sao Paulo. Foram empregados os seguintes iniciadores: ASSR20, OSSR9, OSSR17, CSSR4, CSSR12 e CSSR20, dos quais os quatro ultimos permitiram identificar 22 loci polimorficos. As populacoes de X. fastidiosa presentes em citros no Estado da Bahia apresentam elevada diversidade genetica, com base nos marcadores SSR, com pools genicos distintos e agrupamento geografico. No Litoral Norte, as populacoes do isolado apresentam maior diversidade genetica do que as da regiao do Reconcavo Sul da Bahia.