Large-scale analysis of differential gene expression in coffee genotypes resistant and susceptible to leaf miner-toward the identification of candidate genes for marker assisted-selection.

Background: A successful development of herbivorous insects into plant tissues depends on coordination of metabolic processes. Plants have evolved complex mechanisms to recognize such attacks, and to trigger a defense response. To understand the transcriptional basis of this response, we compare gene expression profiles of two coffee genotypes, susceptible and resistant to leaf miner (Leucoptera coffella).

Phylogenetic relationships of Xylella fastidiosa strains based on 16S-23S rDNA sequences.

In spite of the lack of resolution of Xylella fastidiosa phylogenetic relationships, parsimony analysis of the 16S-23S rDNA sequence from a wide range of hosts has been evaluated in this research. In order to establish an easier method for sequencing the spacer region completely, a new primer pair was designed. The sequences obtained revealed a higher level of variation than that found in 16S gene sequences, with similarity values ranging from 0.