Fire blight disease caused by Erwinia amylovora can infect almost 140 plants of the Rosaceae family and poses a great threat to pome fruits growing all over the world. It needs amylovoran and Type III secretion systems (T3SS) to cause disease in host plants. AmsB, AmsD, AmsE, AmsF, AmsG, AmsJ, AmsI and AmsK proteins are involved in the binding of different galactose, glucuronic acid and pyruvyl subunits to the lipid carrier to form an amylovoran unit. T3SS proteins secreted by E. amylovora are HrpA HrpN, HrpW, AvrRpt2EA, HopC1 and DspA/E. DspA/E, the sole effector of E. amylovora, is secreted by during the formation of pilus T3SS. The chaperone protein of E. amylovora is DsB/F, which is in the IA class. EopB (outer membrane protein) has been characterized as one of the secretory proteins of E. amylovora. In addition to the harpins, the pathogenicity protein DspE and OrfB proteins are secreted via the Hrp-secretory system of E. amylovora. E. amylovora forms a Hrp pilus, which is produced by the structural protein HrpA. Genes encoding antimicrobial proteins cloned and expressed in apples and pears for impart resistance to the pathogen, attacin E are cecropins and lysozymes. The expression of PR2, PR5 and PR8 proteins is increased with E. amylovora infection in apple. Again, the HIPM protein in apples interacts with the E. amylovora HrpN protein, and the HIPM protein is found in higher amounts in flowers than leaves and shoots. In addition, four apple proteins (DIPMs) that interact with E. amylovora effector protein DspA/E have an effective role in endurance. In order to understand the interaction between the plant and the pathogen, it will be possible to understand the proteins that recognize the pathogen in the host, as well as the signal system and plant defense mechanism resulting from the infection. In this study, the roles of proteins associated with pathogenesis as a result of infection of E. amylovora in apples were tried to be revealed.

In the present study, totally 49 samples, which showed the symptoms of leaf and shoot blight and cankers with brown discoloration of necrotic tissues on mature branches, were collected from 22 districts and areas of Konya Province between 2017 and 2019. Presence rate of E. amylovora in collected samples, showing symptoms of the disease, from the province was determined to be 40% for blackberry and raspberry and 33% rosehip for rosehip in three years. Bacteria consistently isolated from the diseased tissues were identified on the basis of biochemical, physiological, and molecular tests, comparing with a reference strain of E. amylovora, isolated from blackberry (Kbb 371). Twenty seven representative bacterial strains were gram-negative, rod-shaped, mucoid, fermentative, positive for levan formation and acetoin production, no growth at 36°C, positive for gelatin hydrolysis, and negative for esculin hydrolysis, indole, urease, catalase, oxidase, arginine dehydrolase, reduction of nitrate, acid production from lactose, and inositol. All strains induced a hypersensitive response in tobacco (Nicotiana tobacum cv. White Burley) 24 h after inoculation with a 108 CFU ml-1 bacterial suspension in sterile distilled water. The strains were identified as E. amylovora using the species-specific primers set A/B (1), which amplified a 1-kb DNA fragment in PCR, and the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) method. In order to fulfill the Koch postulates, pathogenicity test was confirmed by injecting bacterial suspensions of 108 CFU ml-1 in sterile distilled water into the shoot tips of 3-year-old blackberry R. fruticosus cv. Chester, raspberry R. idaeus cv. Heritage and rosehip R. canina. All tests were repeated three times. The bacterium was re-isolated from inoculated plants and identified as E. amylovora. Phytosanitary measures are needed to prevent any further spread of the bacterium as potential inoculum sources to new blackberry, raspberry and rosehip growing areas.

Bu çalışmada, 2017-2019 yılları arasında Konya ilinin 22 ilçe ve bölgesinden yaprak ve sürgünlerde yanıklık, olgun dallarda nekrotik dokuların kahverengi renk değişikliği ile kanser belirtileri gösteren toplam 49 örnek toplanmıştır. İlden toplanan ve hastalık belirtisi gösteren örneklerde E. amylovora bulunma oranı, üç yıl içinde böğürtlen ve ahududu için %40, kuşburnu için %33 olarak belirlenmiştir. Hastalık belirtisi gösteren dokulardan izole edilen bakteriler, böğürtlenden izole edilen bir referans E. amylovora izolatı (Kbb 371) ile karşılaştırmalı olarak biyokimyasal, fizyolojik ve moleküler testler ile tanımlanmıştır. Toplam 27 bakteriyel izolat; Gram negatif, çubuk şekilli, mukoid, fermentatif, levan tipte koloni oluşturan ve asetoin üretimi için pozitif, 36°C'de gelişim göstermeyen, jelatini hidrolize eden, ve eskülin hidrolizi, indol, üreaz, katalaz, laktozdan asit üretimi, inositol, oksidaz, arginin dehidrolaz ve nitrat indirgenmesi testleri için negatif reaksiyonlar vermişlerdir. Tüm izolatlar, steril distile su içinde 108 hücre ml-1 bakteri süspansiyonu ile inokulasyondan sonraki 24 saat sonra içinde tütünde (Nicotiana tobacum cv. White Burley) aşırı duyarlılık reaksiyonuna neden olmuştur. İzolatlar, moleküler olarak PCR'de 1 kb'lik bir DNA parçasını amplifiye eden türe özgü primerler seti (A/B) ve matris destekli lazer desorpsiyon/iyonizasyon kütle spektrometrisi (MALDITOF-MS) kullanılarak etmen E. amylovora olarak tanımlanmıştır. Koch postülatlarını yerine getirmek amacıyla, 3 yaşındaki böğürtlen Rubus fruticosus cv. Chester, ahududu R. idaeus cv. Heritage ve kuşburnu R. canina' nın sürgün uçlarına 108 hücre ml-1 bakteri süspansiyonu ve kontrol bitkilere steril saf su enjekte edilerek patojenite testleri gerçekleştirilmiştir. Bakteri inokule edilen bitkilerden etmen yeniden izole edilerek biyokimyasal ve moleküler testlerle E. amylovora olarak tanımlanmıştır. Potansiyel inokulum kaynağı olarak bakterinin, yeni böğürtlen, ahududu ve kuşburnu yetiştirme alanlarına daha fazla yayılmasını önlemek için bitki sağlığı önlemlerinin alınması gerekmektedir.