CHARACTERISTIC FEATURES OF КЕY-LIKE BACTERIOPHAGES OF ERWINIA AMYLOVORA

Abstract

Aim. To study the heterogeneity of phage isolates obtained from twigs and leaves of pear affected with Erwinia amylovora. Methods. The heterogeneity of phage isolates was studied using the system included low pressure liquid chromatography (LPLC), electron-microscopy analysis of virions and DNA restriction analysis. In this work, the bacteriophages KEY, KEY/7 and KEY/25 were used. Results. the isolate contains a two-component population of KEY-like phage particles, which differ in affinity for DEAE-cellulose. Phages of both subpopulations are represented by virions of B1 morphotype (Siphoviridae family) with regular icosahedral capsids with the diameter of about 77 nm and the length of the caudal appendages close to 172 nm. These phage particles are similar to those of the prototype KEY phage in morphology and size. According to the restriction analysis data, the genomes of the pure line phages KEY/7 and KEY/25 are similar to each other and have the size of about 72 kb, which is 25–27% less than the size of the genome of KEY phage. It is assumed that the phages KEY/7 and KEY/25 represent deletion variants of KEY phage. Conclusions. The heterogeneity of phage isolates get from damaged plants have two main characteristics:the changes of affinity of particles to DEAE-cellulose and the changes of genetic structure of its genome. Further research both phage isolates and phage population are important for study of ecology and opportunity of phage using for biocontrol of dangerous woody plants pathogens.

Keywords

• гетерогенність фагової популяції
• кеy-подібні бактеріофаги
• erwinia amylovora