Microbial Interactions in Olive Agroecosystems

Olive agroecosystems constitute dynamic habitats where diverse microbial communities—comprising bacteria, fungi, archaea and their interactions—modulate tree health, soil fertility and crop resilience. Belowground, root-associated microbiota in the rhizosphere and endosphere drive nutrient cycling, enhance water uptake and contribute to disease suppression by outcompeting or antagonising soilborne pathogens. Aboveground, epiphytic and endophytic assemblages colonise leaves, twigs and xylem vessels, influencing phyllosphere physiology and systemic resistance. Host genotype and environmental context shape these communities, while management practices such as irrigation regime, soil amendments and pest control alter microbial composition and network connectivity. Co-occurrence networks reveal mutualistic and antagonistic links, underscoring the importance of keystone taxa in maintaining community stability. Exploitation of naturally occurring biocontrol agents—such as lactic acid bacteria or Bacillus species—and informed manipulation of the holobiont concept hold promise for sustainable disease management, enhanced oil quality and long-term productivity in Mediterranean-type olive orchards.

Research from Nature Portfolio

Defining the microbial consortia inhabiting the olive root system under uniform agronomic conditions has demonstrated that cultivar genotype exerts a dominant influence on both bacterial and fungal diversity in the rhizosphere and endosphere. Key bacterial genera such as Actinophytocola and Streptomyces prevail in root tissues, while diverse fungal taxa remain largely uncharacterised, suggesting untapped ecological and biotechnological potential in the soil microbiome. Further investigation into genotype-specific pathobiomes during olive knot disease has illustrated that pathogen invasion reconfigures epiphytic and endophytic bacterial assemblages in a cultivar-dependent manner. Susceptible cultivars exhibit greater shifts in community diversity and composition, implicating resident bacteria in disease progression or suppression. These studies collectively reveal how host genetics interact with microbial networks to influence disease outcome and root system function in olive trees.

Microbial Interactions in Olive Agroecosystems publication trend

The graph below shows the total number of articles in microbial interactions in olive agroecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Rhizosphere: The soil region immediately surrounding plant roots, enriched by root exudates and harbouring a high density of microorganisms.

Endosphere: Internal tissues of the plant root or shoot inhabited by endophytic microorganisms that often interact symbiotically with the host.

Epiphyte: A microorganism living on the surface of plant organs, such as leaves or stems, without penetrating internal tissues.

Endophyte: A microbe, typically bacterial or fungal, residing within plant tissues without causing harm, and often conferring benefits like stress tolerance.

Holobiont: The concept of a host organism and its associated microbial community functioning as a single ecological and evolutionary unit.

Co-occurrence network: A representation of microbial associations inferred from statistical correlations, highlighting potential cooperation or competition among taxa.

References

1. Defining the root endosphere and rhizosphere microbiomes from the World Olive Germplasm Collection. Scientific Reports (2019).
2. Impact of plant genotype and plant habitat in shaping bacterial pathobiome: a comparative study in olive tree. Scientific Reports (2020).
3. Antifungal activity of selected lactic acid bacteria from olive drupes. Food Bioscience (2023).
4. Confronting stresses affecting olive cultivation from the holobiont perspective. Frontiers in Plant Science (2023).
5. Exploring Bacterial and Fungal Biodiversity in Eight Mediterranean Olive Orchards (Olea europaea L.) in Tunisia. Microorganisms (2023).