The first doctoral dissertation conducted under the supervision of professor Ewa Łojkowska was entitled “The role of secondary pectate lyases PelI, PelL, PelZ in the pathogenesis of Erwinia chrysanthemi species and evaluation of the potential of primers based on the pelL gene sequence for the diagnosis of this species” and was prepared by Sylwia Jafra in 1999.
Subsequent studies concerned monitoring of biodiversity of bacteria from the species: Erwinia atroseptica (currently Pectobacterium atrosepticum), Erwinia carotovora (curretly Pectobacterium carotovorum) and Erwinia chrysanthemi (currently from the genus Dickeya), which have been isolated from potato seed plantations. Besides, scientific focus was also put on molecular markers that might be useful for the testing of intra-species variation. These works were carried out in close coollaboration with the State Plant Health and Seed Inspection Service in Poland. The outcomes of these studies included two consecutive doctoral dissertations: “Detection, identification and evaluation of genetic diversity in the Polish collection of Erwinia carotovora subsp. atroseptica / Pectobacterium carotovorum subsp. atrosepticum” prepared by Wojciech Śledź (2002) and “Application of molecular markers in studying genetic variability in the genus Erwinia” written by Małgorzata Waleron (2002).
In the following years, our research focused on regulation of virulence in Dickeya and search for biological factors that could limit the spread of infection caused by pectinolytic bacteria. A doctoral dissertation in this field entitled “Analysis of factors determining silencing of intercellular signaling based on acyl-homoserine lactones produced by Ochrobactrum sp. A44″ was prepared by Joanna Przysowa (2008).
Outcomes of continuation of studies on the Polish population of blackleg and soft rot-causing bacteria in addition to focus on the development of modern methods designated for detection and identification of these phytopathogens were enclosed in doctoral dissertation written by Monika Sławiak in 2009 under the title “New molecular markers and probes for detection, identification and classification of bacteria from the genera Pectobacterium and Dickeya”.
Subsequently, we searched for biological factors that might protect potato plants from pectinolytic bacteria. Sylwia Jafra in her habilitation thesis entitled “Analysis of the factors degrading N-acyl-homoserine lactones, compounds of key importance for the pathogenesis of pectinolytic bacteria” (2011) characterized a bacterial strain belonging to the genus Ochrobactrum spp. that produced an enzyme degrading N-acyl-homoserine lactones, signaling molecules involved in bacterial quorum sensing. These results may find application in biocontrol of bacterial diseases.
Further looking for biological compounds of antibacterial activity led to defending by Anna Szpitter in 2012 her doctoral dissertation “The mechanisms of antibacterial properties of extracts from insectivorous plants belonging to the Dionaea muscipula species”.
Another research topic aimed at using bacteriophages for protecting plants from pectinolytic bacteria. Scientific achievement entitled “New lytic bacteriophages with a wide host range and their potential for biological protection of potato (Solanum tuberosum L.) against pectinolytic bacteria of the genera Pectobacterium and Dickeya“ was the basis for Robert Czajkowski‘s habilitatation.
Further work of our PhD students focused on studying molecular factors determining the pathogenicity of Dickeya solani. In 2015 Marta Potrykus defended her doctoral dissertation entitled “Characterization of the molecular mechanism determining the pathogenicity of Dickeya spp. on plants”. Also in that year Małgorzata Golanowska obtained PhD for the thesis “Characteristics of Dickeya solani strains and identification of compounds of plant origin inducing the production of virulence factors by these bacteria”.
At the same time, application of new technologies for identifying and differentiating bacterial plant pathogens was further investigated. In 2017, Małgorzata Waleron obtained habilitation on the basis of a scientific achievement entitled: “Development of methods for identification and genetic differentiation of bacterial plant pathogens by using RFLP techniques and sequencing of housekeeping genes”.
Then, comparative genomics and pangenome-oriented studies were also carried out in the following PhD theses:„Molecular determinants in the interaction of plant pathogenic bacteria from the species Dickeya solani and Pectobacterium atrosepticum under different temperatures” by Natalia Kaczyńska (2018), “Genotypic and phenotypic characterisation of bacteria from Dickeya solani species and the development of innovative control methods against bacterial pathogens” by Agata Motyka-Pomagruk (2019) and “Characterization of the biodiversity and pan-genome of bacterial pathogens from Pectobacterium parmentieri species” by Sabina Żołędowska (2019).
Currently, MSc Weronika Babińska and MSc Jakub Orłowski are conducting studies in our laboratory for their PhD theses.