Interactions between tomato (Lycopersicon esculentum) root tissues and the mycoparasitePythium oligandrum

Rey, Patrice; Benhamou, Nicole; Wulff, E. G.; Tirilly, Y.

doi:10.1006/pmpp.1998.0159

Cited by 27 publications

(13 citation statements)

References 35 publications

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“…A critical feature of the relationships established between P. oligandrum and the plant relies on its remarkable ability to rapidly colonize all root tissues in a way similar to pathogenic oomycetes and to subsequently degenerate without causing host tissue damage (Rey et al, 1998b). This unusual behaviour, leading to net fitness benefits for the plant, suggests that P. oligandrum, unlike other beneficial micro-organisms (Lorito et al, 2010), does not have the ability to cope with the host immune response that is triggered at the onset of MAMP perception.…”

Section: Introductionmentioning

confidence: 99%

Pythium oligandrum: an example of opportunistic success

et al. 2012

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Pythium oligandrum, a non-pathogenic soil-inhabiting oomycete, colonizes the root ecosystem of many crop species. Whereas most members in the genus Pythium are plant pathogens, P. oligandrum distinguishes itself from the pathogenic species by its ability to protect plants from biotic stresses in addition to promoting plant growth. The success of P. oligandrum at controlling soilborne pathogens is partly associated with direct antagonism mediated by mycoparasitism and antimicrobial compounds. Interestingly, P. oligandrum has evolved with specific mechanisms to attack its prey even when these belong to closely related species. Of particular relevance is the question of how P. oligandrum distinguishes between self-and non-self cell wall degradation during the mycoparasitic process of pathogenic oomycete species. The ability of P. oligandrum to enter and colonize the root system before rapidly degenerating is one of the most striking features that differentiate it from all other known biocontrol fungal agents. In spite of this atypical behaviour, P. oligandrum sensitizes the plant to defend itself through the production of at least two types of microbe-associated molecular patterns, including oligandrin and cell wall protein fractions, which appear to be closely involved in the early events preceding activation of the jasmonic acid-and ethylene-dependent signalling pathways and subsequent localized and systemic induced resistance. The aim of this review is to highlight the expanding knowledge of the mechanisms by which P. oligandrum provides beneficial effects to plants and to explore the potential use of this oomycete or its metabolites as new disease management strategies.

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Section: Introductionmentioning

confidence: 99%

Pythium oligandrum: an example of opportunistic success

et al. 2012

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“…In particular, Pythium oligandrum is an effective biocontrol agent (2,14,49,64). This oomycete colonizes roots without damaging the host plant cells (24,45) and survives in the rhizosphere, where it exerts its biocontrol (57). P. oligandrum acts through both direct effects (mycoparasitism, antibiosis, and competition for nutrients and space) and indirect effects (stimulation of plant defense reactions and plant growth promotion) (49).…”

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confidence: 99%

Influence of Pythium oligandrum Biocontrol on Fungal and Oomycete Population Dynamics in the Rhizosphere

Vallance

Floch

Déniel

et al. 2009

Appl Environ Microbiol

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Fungal and oomycete populations and their dynamics were investigated following the introduction of the biocontrol agent Pythium oligandrum into the rhizosphere of tomato plants grown in soilless culture. Three strains of P. oligandrum were selected on the basis of their ability to form oospores (resting structures) and to produce tryptamine (an auxin-like compound) and oligandrin (a glycoprotein elicitor). Real-time PCR and plate counting demonstrated the persistence of large amounts of the antagonistic oomycete in the rhizosphere throughout the cropping season (April to September). Inter-simple-sequence-repeat analysis of the P. oligandrum strains collected from root samples at the end of the cropping season showed that among the three strains used for inoculation, the one producing the smallest amount of oospores was detected at 90%. Single-strand conformational polymorphism analysis revealed increases in the number of members and the complexity of the fungal community over time. There were no significant differences between the microbial ecosystems inoculated with P. oligandrum and those that were not treated, except for a reduction of Pythium dissotocum (ubiquitous tomato root minor pathogen) populations in inoculated systems during the last 3 months of culture. These findings raise interesting issues concerning the use of P. oligandrum strains producing elicitor and auxin molecules for plant protection and the development of biocontrol.

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“…var. Prisca) root system without inducing extensive cell damage (Rey et al, 1998) and to trigger an array of structural defense-related reactions upon challenge with Fusarium oxysporum f.sp. radicis-lycopersici (Benhamou et al, 1997).…”

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confidence: 99%

Oligandrin. A Proteinaceous Molecule Produced by the MycoparasitePythium oligandrum Induces Resistance to Phytophthora parasitica Infection in Tomato Plants

Picard¹,

et al. 2000

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A low-molecular weight protein, termed oligandrin, was purified to homogeneity from the culture filtrate of the mycoparasitic fungus Pythium oligandrum. When applied to decapitated tomato (Lycopersicon esculentum Mill. var. Prisca) plants, this protein displayed the ability to induce plant defense reactions that contributed to restrict stem cell invasion by the pathogenic fungus Phytophthora parasitica. According to its N-terminal sequence, low-molecular weight, acidic isoelectric point, ultraviolet spectrum, and migration profile, the P. oligandrum-produced oligandrin was found to share some similarities with several elicitins from other Phytophthora spp. and Pythium spp. However, oligandrin did not induce hypersensitive reactions. A significant decrease in disease incidence was monitored in oligandrin-treated plants as compared with water-treated plants. Ultrastructural investigations of the infected tomato stem tissues from non-treated plants showed a rapid colonization of all tissues associated with a marked host cell disorganization. In stems from oligandrin-treated plants, restriction of fungal growth to the outermost tissues and decrease in pathogen viability were the main features of the host-pathogen interaction. Invading fungal cells were markedly damaged at a time when the cellulose component of their cell walls was quite well preserved. Host reactions included the plugging of intercellular spaces as well as the occasional formation of wall appositions at sites of potential pathogen entry. In addition, pathogen ingress in the epidermis was associated with the deposition of an electron-opaque material in most invaded intercellular spaces. This material, lining the primary walls, usually extended toward the inside to form deposits that frequently interacted with the wall of invading hyphae. In the absence of fungal challenge, host reactions were not detected.

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Interactions between tomato (Lycopersicon esculentum) root tissues and the mycoparasitePythium oligandrum

Cited by 27 publications

References 35 publications

Pythium oligandrum: an example of opportunistic success

Pythium oligandrum: an example of opportunistic success

Influence of Pythium oligandrum Biocontrol on Fungal and Oomycete Population Dynamics in the Rhizosphere

Oligandrin. A Proteinaceous Molecule Produced by the MycoparasitePythium oligandrum Induces Resistance to Phytophthora parasitica Infection in Tomato Plants

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