Functional analysis of Xanthomonadales-like type IV secrection system and distribution of Xanthomonadales-like type IV and type VI secretion systems in Xanthomonas translucens

Details

Supervisors

Bragard, Claude ; Peduzzi, Chloé

Faculty

Faculté des bioingénieurs

Degree label

Master [120] : bioingénieur en sciences agronomiques, à finalité spécialisée

Abstract

Xanthomonas translucens is a phytopathogenic bacterium of small grain cereals that causes bacterial leaf streak disease. This bacterium is widespread throughout the world and cause significant damage to economically important crops. One of the reasons for its prosperity is its ability to occupy competitively small grain cereals. Bacteria from Xanthomonas genus has been shown to be able to kill other bacteria, via one of its secretion systems, injecting a cocktail of toxic enzymes into target cells in a contact-dependent manner. Interestingly, the literature indicates that two secretion systems fulfill such role in the biology of the genus Xanthomonas with slightly different mechanisms: the Xanthomonadales-like Type IV secretion system (X-T4SS) and the i4 clade of the Type VI secretion system (i4-T6SS). Moreover, it seems that the different strains of Xanthomonas translucens never present these two systems at the same time, indicating a mutual exclusion between X-T4SS and i4-T6SS, which are heterogeneously distributed within the species. The goal of this work is to shed light on these two systems in Xanthomonas translucens through two lines of research: to experimentally demonstrate the functional role of X-T4SS and to study the distribution of X-T4SS and T6SS.