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

Abstract

Bacteria from the genus Pseudomonas have been extensively studied for their capacity to act as biological control agents of disease and pests and for their ability to enhance and promote crop production in agricultural systems. While initial research primarily focused on the human pathogenic bacteria Pseudomonas aeruginosa, recent studies indicate the significance of type VI secretion (T6SS) in other Pseudomonas strains for biocontrol purposes. This system possibly plays a pivotal role in restricting the biological activity of target microorganisms and may also contribute to the bolstering of the survival capabilities of the bacteria within their applied environment. The type VI secretion system is a phage-like structure used to translocate effectors into both prokaryotic and eukaryotic target cells. T6SSs are involved in a myriad of interactions, some of which have direct implications in the success of Pseudomonas as biocontrol agents. The prevalence of T6SSs in the genomes of Pseudomonas species is notably greater than the estimated 25% occurrence rate found in Gram-negative bacteria. This observation implies that T6SS likely plays a pivotal role in the survival and fitness of Pseudomonas. This review provides a brief overview of T6SS, its role in Pseudomonas with biocontrol applications, and future avenues of research within this subject matter.

Magnesium oxide nanoparticles reduce clubroot by regulating plant defense response and rhizosphere microbial community of tumorous stem mustard (Brassica juncea var. tumida)

“…In this study, MgO NPs treatments significantly increased the relative abundance of Pseudomonas , Sphingopyxis , Acidovorax , Var iovorax , Bosea in soil ( Supplementary Table S2 ). Among these genera, Pseudomonas , as a biological control agent for pests and diseases, has been widely utilized in enhancing and facilitating crop production ( Navarro-Monserrat and Taylor, 2023 ). Notably, it exhibited the highest relative abundance in the 500 and 1,500 mg/L MgO NPs treatments ( Supplementary Table S2 ).…”

“…Notably, it exhibited the highest relative abundance in the 500 and 1,500 mg/L MgO NPs treatments ( Supplementary Table S2 ). P. putida , which is one of the most studied species beneficial for plant development and/or biological control of plant pathogens ( Navarro-Monserrat and Taylor, 2023 ), was the biomarker specie in the 500 mg/L MgO NPs treatment ( Supplementary Figure S2 ). Pseudomonas has also been proved play an important role in clubroot disease suppression ( Zhang et al, 2022 ).…”

A review on mechanisms and prospects of endophytic bacteria in biocontrol of plant pathogenic fungi and their plant growth-promoting activities

“…is important for its biocontrol activity. The T6SS is a syringe-like structure resembling a phage tail capable of secreting effector proteins into targeted prokaryotic and eukaryotic cells [ 144 , 145 ]. This system has been recognized as a powerful antifungal weapon, and fungal-specific effector proteins, Tfe1 and Tfe2, have been identified.…”