Pseudomonas–Plant Interactions

Abstract

Pseudomonas is a diverse genus containing a large number of species with a variety of catabolic and metabolic abilities. This diversity allows for the colonization of an array of environmental niches and interactions with a wide range of eukaryotic hosts as saprotrophs, endophytes, commensals, plant pathogens and opportunistic human pathogens [1][2][3][4][5]. Pseudomonas species are of great interest to researchers in the fields of plant, soil and human-associated microbiology, and as such the genomic sequences of a range of Pseudomonas strains have been determined or are currently in progress (Table 13.1). Pseudomonas-plant interactions are found ubiquitously in nature and encompass a growing number of plant species, many of which are important to commercial horticulture. These interactions fall into two general groups: those that are beneficial and those that are detrimental to the host plants health (Figure 13.1). Pseudomonas sp. which successfully interact with plant hosts ultimately gain an advantage over the competing microorganisms in the immediate environment. This is usually achieved by occupying an exclusive niche provided by the plants surfaces and obtaining growth substrates exuded from the plant roots or released by disease-related breakdown of plant cells in the case of pathogenic interactions. The development of such interactions between Pseudomonas and host plants usually involves avoidance, subversion and sometimes even stimulation of the host plants defenses. In return the plant host can respond to the presence of the Pseudomonas sp. by modulating defense mechanisms, and engaging in signaling between itself and the infecting bacterium in an attempt to further promote beneficial interactions or suppress pathogenic ones. The molecular game of cat and mouse between the partners, with each attempting to benefit from the other, has evolved over millions of years and provides us now with a vast array of Pseudomonas-plant interaction mechanisms to unravel. Indeed, genetic and physiological similarities Pseudomonas. Model Organism, Pathogen, Cell Factory. Edited by Bernd H.A. Rehm

Genomic analysis and temperature-dependent transcriptome profiles of the rhizosphere originating strain Pseudomonas aeruginosa M18

“…The predominant phenazine produced in strain M18 is PCA, especially at 28°C, rather than PYO produced in other nosocomial originating P. aeruginosa strains [ 11 ]. Both PCA and Plt compounds produced by fluorescent Pseudomonas species are considered to play an important role in microbial competitiveness and combating plant pathogens [ 50 ]. To our knowledge, the strain M18 is the first strain that was reported to produce both PCA and Plt simultaneously, and the synergistic antibiotic effect of PCA and Plt can result in strong activity to protect plants from fungal phytopathogen infections.…”

Biochemical and genomic comparison of inorganic phosphate solubilization in Pseudomonas species

“…Soil microorganisms are therefore considered an integral part of the soil phosphorus cycle. The use of bacterial inoculants as biofertilizers, which act to increase the levels of bioavailable phosphate in the rhizosphere, is seen as a potential component in modern environmentally friendly agricultural practices in terms of reducing the expense of phosphate fertilization (which is a finite resource), while maintaining suitable crop yields and reducing agricultural pollution (Morrissey et al., 2004; Vassilev et al., 2006; Miller et al., 2008). The ability to mineralize insoluble organic phosphates, such as phytates, phosphomono‐, di‐ and tri‐esters and organophosphonates via the actions of various phosphatase, phytase and phosphonatase enzymes, has been studied in several Pseudomonas spp.…”

Anti-TMV Activities of Pantoea agglomerans Lipopolysaccharides in vitro

“…aureofaciens B-111 and B-306, since these fractions turned out to be toxic for indicator plants. At the same time, according to the literature [5,7], the protective effect of LPS is due to a part of the LPS molecule containing both lipid A and the associated OG-core.…”

“…It`s known [5] that the antiviral effect of a number of natural substances of certain plant extracts does not exceed 40-50 %. Few reports indicate that some bacteria and yeasts [6,7] are capable of exhibiting antiviral activity. Thus, recently it has been shown that lipopolysaccharides (LPS) of some bacteria, in particular representatives of the genus Pseudomonas, play a significant role in the interaction of plants with pathogens [8].…”