Characterization of an endophytic bacterium (<i>Pseudomonas aeruginosa</i>), originating from tomato (<i>Solanum lycopersicum</i> L.), and its ability to inhabit the parasitic weed <i>Phelipanche aegyptiaca</i>

Abstract

is an obligate holo-parasitic weedlacking a functional photosynthetic system, which subsists on roots of a wide range of host crops, causing severe losses in yield quality and quantity. The parasite and its host are connected through their vascular system, forming a unique ecological system that enables the exchange of various substances. In a previous study, it was suggested that endophytic bacteria, which naturally inhabit the internal tissues of plants, can also be transmitted from the parasitic weed to its host and <i>vice versa</i>. In the current study, we investigate the characteristics of a previously isolated <i>Pseudomonas</i> sp. <i>PhelS10</i> strain using both biochemical and molecular methods. This isolate was obtained from tomato plant tissue and was able to reduce <i>P. aegyptiaca</i> parasitism, and thus it may serve as a biocontrol agent. Our results revealed that production of <i>Pseudomonas aeruginosa</i> quinolone signal (PQS) was 2.1 times higher than that of the standard <i>Pseudomonas aeruginosa</i> strain (PAO1), which contributed to a 22% higher biofilm formation capability. <i>PhelS10</i> strain was detected in the xylem of tomato plants using FISH analysis. In addition, <i>PhelS10</i> strain was found in the parasitic weed's inner tissues, confirming the hypothesis that endophytic bacteria traffic between the host plant and its parasitic weed.