During the first three-four years after the outbreak of fire blight in Emilia-Romagna, pear was the host plant with the higher frequency of the disease. In the following years, the frequency of cases in host plants other than pear increased, particularly on apple and hawthorn plants. This diffusion of cases in host plants other than pear plants was explained as a case of adaptation, but the molecular bases of this phenomenon are still not known, both in Italy and abroad. The results obtained by an AFLP analysis on the evolution of the Emilian Erwinia amylovora (Ea) populations pointed out that the isolates from host plants other than pear were undistinguishable between themselves (Minardi et al., this workshop). However, the AFLP technique compares profiles obtained by the PCR amplification of DNA fragments selected on the entire genome. In this research work we hypothesized that the adaptation to other hosts may modify the genetic and/or genotypic frequencies in the Ea sub-populations, with possible effects even on the virulence. The dspEF locus next to the hrp gene cluster of Ea is essential for pathogenicity, but not for elicitation of the hypersensitive reaction. Moreover DspE is a homolog of AvrE of Pseudomonas syringae (Bogdanove et al., 1998). In this work we have started a comparative analysis of the sequence of the dspE gene which can be one of the likely target of selective pressure in different hosts. For this purpose oligonucleotides based on the dspE gene of Ea321 strain were used as primers in a PCR with the total DNA of Ea 1077/7 as template. A PCR product, analyzed on an 8% polyacrylamide gel, was similar in size to dspE gene ( 5.6 kb). Restriction fragment analysis of the PCR product was carried out using the following restriction endonucleases: EcoRI, AluI, HaeII, MspI, SauIII, PstI, HhaI, MseI, RsaI. As a result of the comparative analysis of the amplicone, obtained from several Ea strains isolated from different host plants, the variability related to the adaptation to the host plant was studied.
Minardi, P., Morbio, M., Mucini, S., Mazzucchi, U. (2004). Molecular characterization of the dspE gene from Erwinia amylovora strains isolated from different host plants. Bologna : Avenue Media.
Molecular characterization of the dspE gene from Erwinia amylovora strains isolated from different host plants
MINARDI, PAOLA;MUCINI, SARA;MAZZUCCHI, UMBERTO
2004
Abstract
During the first three-four years after the outbreak of fire blight in Emilia-Romagna, pear was the host plant with the higher frequency of the disease. In the following years, the frequency of cases in host plants other than pear increased, particularly on apple and hawthorn plants. This diffusion of cases in host plants other than pear plants was explained as a case of adaptation, but the molecular bases of this phenomenon are still not known, both in Italy and abroad. The results obtained by an AFLP analysis on the evolution of the Emilian Erwinia amylovora (Ea) populations pointed out that the isolates from host plants other than pear were undistinguishable between themselves (Minardi et al., this workshop). However, the AFLP technique compares profiles obtained by the PCR amplification of DNA fragments selected on the entire genome. In this research work we hypothesized that the adaptation to other hosts may modify the genetic and/or genotypic frequencies in the Ea sub-populations, with possible effects even on the virulence. The dspEF locus next to the hrp gene cluster of Ea is essential for pathogenicity, but not for elicitation of the hypersensitive reaction. Moreover DspE is a homolog of AvrE of Pseudomonas syringae (Bogdanove et al., 1998). In this work we have started a comparative analysis of the sequence of the dspE gene which can be one of the likely target of selective pressure in different hosts. For this purpose oligonucleotides based on the dspE gene of Ea321 strain were used as primers in a PCR with the total DNA of Ea 1077/7 as template. A PCR product, analyzed on an 8% polyacrylamide gel, was similar in size to dspE gene ( 5.6 kb). Restriction fragment analysis of the PCR product was carried out using the following restriction endonucleases: EcoRI, AluI, HaeII, MspI, SauIII, PstI, HhaI, MseI, RsaI. As a result of the comparative analysis of the amplicone, obtained from several Ea strains isolated from different host plants, the variability related to the adaptation to the host plant was studied.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
