Transcript analysis of some pathogenicity-related elements in an Iranian A* isolate of Xanthomonas citri subsp. citri

Asiatic citrus canker is a devastating disease resulting in drastic economic losses in citriculture worldwide. Amongst three different types of the disease, i.e. A, A* and Aw, the A* type is genetically less known. In order to comprehend the behavior of the Asiatic citrus canker A*-type strain (Xanthomonas citri subsp. citri) in the vicinity of the host cells, a targeted semi-quantitative transcript analysis approach via RT-PCR was carried out. A subset of sixteen genes, as representative of different steps involved in phytopathogencity, was analyzed on the culture medium (as uninduced) and compared with the subset isolated from the infected Mexican lime (Citrus auarntifolia L.) plants (as induced). The results showed that certain genes were up-regulated in induced condition, suggesting a putative role in bacteria-host interaction. Furthermore, the transcripts in induced condition could be classified into constitutive, early- and late-responsive genes, demonstrating their functional relevance during the host-pathogen interaction.