Sporulation Activated via σ ^W Protects Bacillus from a Tse1 Peptidoglycan Hydrolase Type VI Secretion System Effector

Abstract

The study of bacterial interactions is helping to define species-specific strategies used to modulate the competition dynamics underlying the development of community compositions. In this study, we deciphered the role of Pseudomonas T6SS when competing with Bacillus and the mechanism by which a T6SS-toxin modifies Bacillus physiology.

T6SS-mediated competition byStenotrophomonas rhizophilashapes seed-borne bacterial communities and seed-to-seedling transmission dynamics

“…For instance, several monoderm strains tested in this work are resistant to the T6SS of CFBP13503. This resistance could be explained by the thick peptidoglycan layer of monoderms, which requires specific T6SS effectors to be perforated (63,64) or the induction of survival mechanisms such as sporulation, which has been observed in B. subtilis in response to the secretion of a muramidase-type effector secreted by P. chlororaphis (65). Concerning Oxalobacteraceae, while certain strains exhibit resistance within the communities, they paradoxically show susceptibility when individually confronted with S. rhizophila CFBP13503.…”

T6SS: A Key to Pseudomonas’s Success in Biocontrol?

“…Pseudomonas chlororaphis are common inhabitants of the soil and plant tissue and have been extensively reported for their phytostimulant and biocontrol capacities. P. chlororaphis PCL1606, a model strain for biocontrol studies [84], was used in two studies to study T6SS-mediated interactions between PCL1606 and another plant-beneficial bacterium in Bacillus subtillis [85,86]. The first study showed a T6SS-mediated predation of B. subtillis cells that lack an extracellular matrix.…”

“…Furthermore, the study showed that this T6SS-led predation of B. subtillis by PCL1606 led to sporulation in B. subtillis, potentially serving as a survival mechanism. The subsequent study by Perez-Lorente et al [86] identified Tse1, a hydrolase, and the T6SE involved in degrading the peptidoglycan wall and inducing sporulation in B. subtillis.…”

“…Detected upregulation of T6SS-related genes during the production of phenazine-1-carboxamide [89] Pseudomonas chlororaphis PLC1606 Demonstrated activation of T6SS in P. chlororaphis led to sporulation of Bacillus subtilis [85,86] Pseudomonas sp. JY-Q Reported dual roles of the T6SS effector TseN, which played a role in bacterial competition and nicotine degradation [90]…”