Abstract
Plant-growth promotion has been linked to the Pseudomonas genus since the beginning of this research field. In this work, we mined the genome of an Argentinean isolate of the recently described species P. donghuensis. Strain SVBP6, isolated from bulk soil of an agricultural plot, showed a broad antifungal activity and several other plant-probiotic activities. As this species has been recently described, and it seems like some plant-growth promoting (PGP) traits do not belong to the classical pseudomonads toolbox, we decide to explore the SVBP6 genome via an bioinformatic approach. Genome inspection confirmed our previous in vitro results about genes involved in several probiotic activities. Other genetic traits possibly involved in survival of SVBP6 in highly competitive environments, such as rhizospheres, were found. Tn5 mutagenesis revealed that the antifungal activity against the soil pathogen Macrophomina phaseolina was dependent on a functional gacS gene, from the regulatory cascade Gac-Rsm, but it was not due to volatile compounds. Altogether, our genomic analyses and in vitro tests allowed the phylogenetic assignment and provided the first insights into probiotic properties of the first P. donghuensis isolate from the Americas.
Highlights
Among all soil bacterial genera having a representative described as a Plant-Growth Promoting Microbe (PGPM), the genus Pseudomonas comprise a wide variety of probiotic species, with distinct mechanisms of action that strengthen plant health, either directly or indirectly [1,2]
SVBP6 can grow between 4 ̊C and 35 ̊C in rich media, like nutrient agar (NA), even though the optimal growth temperature is 28 ̊C, and it belongs to the r-strategist group of microorganisms [8]
The assembled draft genome of SVBP6 consisted of 5,701,342 bases, for which 5253 PEGS were assigned, being 78.3% of those coding sequences related to a known subsystem (Table 2)
Summary
Among all soil bacterial genera having a representative described as a Plant-Growth Promoting Microbe (PGPM), the genus Pseudomonas comprise a wide variety of probiotic species, with distinct mechanisms of action that strengthen plant health, either directly or indirectly [1,2]. Several pseudomonads have demonstrated production of different kinds of secondary metabolites involved in antagonism to pathogens, phytostimulation or nutrient supply, and an ability to degrade complex organic compounds, being able to contribute to plant growth, and to bioremediation of soils [2,3,4,5,6]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. They contributed with the money to carry out the described assays and to pay for the publication fee
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
