Does plant -microbe's common Inter Simple Sequence Repeat lead to a new recombination? A novel mechanism of pathogenicity

AbstractA total of eight varieties of the mango from an orchard were studied using molecular markers to understand the host-pathogen interaction. From the infected leaves of the plant, a total of the 8 bacterial pathogens (Exiguobacterium arabatum, Pseudomonas mendocina, Pantoea dispersa, Bacillus sp. Pantoea ananatis, Micrococcous luteus, Microbacterium_sp., Enterobacter cloacae) were isolated and identified. All the host varieties of mango were distinguished for the genetic diversity using the Inter Simple Sequence Repeat (ISSR) DNA markers. This set of ISSR marker primers were also used for the mango pathogens. PCR amplification of the ISSR primers showed polymorphic and monomorphic band patterns in the host plants and in their pathogens. The monomorphic band generated by PCR amplification in the host and in the pathogen, by the common primer, is selected and used for PCR hybridization technique. PCR products obtained from the host, pathogen and hybridization were cloned, sequenced and compared. A multiple sequence alignment of these sequences revealed that the product of hybridization PCR was mixture of host and pathogen sequences. On this basis, we hypothesize a possibility for the recombination of host-microbes DNA as one of the mechanisms of pathogenicity for the plant pathogens using hybrid PCR technique. The possible mechanism of recombination for plant host and its pathogen is discussed. HighlightsInter Simple Sequence Repeat markers used to (i) Fingerprint the pathogens and their host (mango) and (ii) for study of the possibilities for the recombination as mechanism of pathogenicity.