Your browser does not support JavaScript!

Home    Search  

Results - Details

Search command : Author="Καλαντίδης"  And Author="Κρίτων"

Current Record: 17 of 65

Back to Results Previous page
Next page
Add to Basket
[Add to Basket]
Identifier 000431567
Title Deciphering the three-way interaction among Bacillus amyloliquefaciens MBI600, plants and phytopathogenic bacteria
Alternative Title Μελέτη της τριπλής αλληλεπίδρασης μεταξύ του βιολογικού παράγοντα Bacillus amyloliquefaciens MBI600, φυτών και φυτοπαθογόνων βακτηρίων
Author Δημοπούλου, Αναστασία Γ.
Thesis advisor Καλαντίδης. Κρίτων
Reviewer Σκανδάλης, Νικόλαος
Βόντας, Ιωάννης
Μπουριώτης, Βασίλης
Βασιλάκος, Νίκων
Χατζηνικολάου, Δημήτρης
Σαρρής, Παναγιώτης
Μόσχου, Παναγιώτης
Abstract The objective of this study was to elucidate the mechanisms of the three-way plant-B. amyloliquefaciens MBI600-bacterial pathogen interaction. A holistic approach was implemented; at first, the bactericidal activity of B. amyloliquefaciens MBI600 was evaluated in vitro and in planta against various bacterial pathogens. MBI600 showed antibacterial activity in vitro against both gram- and gram+ species. Among the tested species, Clavibacter michiganensissubsp. michiganensis, Ralstonia solanacearum, and Xanthomonas spp. were of high susceptibility, Erwinia amylovora of intermediate susceptibility and E. chrysanthemi and Pseudomonas spp. of low/no susceptibility. Foliar application of Serifel, the commercial formulation of MBI600, inhibited infection of tomato plants by the soil-borne phytopathogen R. solanacearum. It also displayed biocontrol activity against X. campestris pv. vesicatoria and reduced disease symptoms caused by P. syringae pv. tomato, even if its population density was not affected significantly. In support, wildfire disease development and population density of its causing agent were impaired significantly in Nicotiana benthamiana leaves. MBI600 produced and secreted bacillibactin, a catecholate siderophore, under iron depletion growth conditions. In vitro and in planta tests suggested that production of bacillibactin resulted in a broadening of the MBI600 target range among phytopathogens. The ability of MBI600 to colonize different plant was also evaluated. Results suggested that ΜΒΙ600 effectively colonized, in a dose-dependent manner, tomato and corn roots as well as leaves of tomato, N. benthamiana and lettuce plants following Serifel application. Furthermore, microbiological tests and expression of genes involved in rhizosphere competence revealed that colonization is facilitated by root exudates and elicitorsfrom competitive species, which enhanced swarming of MBI600 and synthesis of bactericidal antibiotics. Finally, the activation of immune responses of tomato plants in the presence of MBI600 or its metabolites was investigated based on the expression of defenserelated genes and transcriptomic analysis. Foliar application of Serifel activated defense mechanisms in a dose-dependent manner; low dosage activated only SAresponsive genes (npr1, pr1b1) whereas use of suggested dosage resulted in the activation of all JA/ET-responsive genes assessed (erf1, loxD, myc2), while the SA signaling pathway was still active. These results suggested a synergy between SA and JA/ET – responsive pathways, which was confirmed in experiments using MBI600 metabolites. Furthermore, MBI600 metabolites suppressed absisic acid and enhanced auxin signaling pathways. They also activated components of Jasmonic acid (JA) and ethylene (ET) biosynthesis and signaling pathways. In contrast to leaf application, CFCF did not affect SA-responsive genes targeted in this study.
Language English
Subject Hormonal signaling pathways
ISR
PGPR - pathogen interactions
SAR
Βιολογική καταπολέμηση
Βιολογικοί παράγοντες
Επαγωγή άμυνας φυτών
Μονοπάτια σηματοδότησης φυτοορμονών
Φυτοπαθογόνα βακτήρια
Issue date 2020-04-09
Collection   School/Department--School of Sciences and Engineering--Department of Biology--Doctoral theses
  Type of Work--Doctoral theses
Permanent Link https://elocus.lib.uoc.gr//dlib/1/3/a/metadata-dlib-1598436912-325879-4084.tkl Bookmark and Share
Views 322

Digital Documents
No preview available

Download document
View document
Views : 3