Genetic and pathological relationships among Xyllela fastidiosa strains

Abstract

The availability of the complete sequence of nucleotides of the genome of the strain of Xylella fastidiosa (Xf) affecting citrus opens a unique opportunity for further assessment of genetic relationship among all Xf strains. In this work we propose to evaluate pathological similarities and host specificity among the strains that affect the economically important crops citrus, coffee and plum in Brazil. Pathological similarities will be assessed by comparison of nucleotide and amino acid sequences, copy number and expression levels of distinct genes supposedly involved in pathogenicity and virulence, as suggested by BLAST analysis of the citrus Xf sequences. Host specificity will be assessed by artificial cross inoculation of citrus, coffee and Japanese plum seedlings with strains recovered from these hosts. The information obtained with this work will be important for a better understanding of the mechanisms of pathogenicity in this organism. In addition, this information is essential for further progress in epidemiological! studies and in establishing appropriated practices for disease control. (AU)