Characterization of Core Microbiomes of Olive Tree Rhizospheres Under Drought Stress Conditions
Author(s)
Date Issued
2025
Type
article
Volume
15
Issue
17
Start Page
9667
Journal or Series
Abstract
Drought stress poses a significant threat to olive cultivation in Mediterranean regions.
This study investigated the resilience and functional adaptation of root-associated and
rhizosphere soil microorganisms of four olive cultivars under contrasting water regimes
(irrigated vs. drought) across seasons. Using a combination of amplicon-targeted metage
nomics, phylogenetic analysis, and text mining of the scientific literature, we identified
a conserved core microbiome and revealed that drought stress significantly alters the
structure of root-associated—but not rhizosphere soil—bacterial communities. Potential
functional profiling indicated that drought conditions enriched for genes involved in
stress response pathways, including branched-chain amino acid transport, glutathione
S-transferase activity, thioredoxin reductase, and chemotaxis. Text mining co-occurrence
networks highlighted strong associations between some key bacterial genera and plant
growth-promoting functions like phytohormone production and biocontrol. Furthermore,
weidentified Solirubrobacter, Microvirga, and Pseudonocardia as the primary contributors to
these drought-resilience functions. The stability of the soil microbiome suggests functional
redundancy, whereas the restructuring of the root endophytic compartment indicates active
plant selection for beneficial microbes. Our findings provide a foundation for developing
tailored microbial consortia (SynComs) to enhance drought tolerance in olive trees and
support sustainable agriculture in water-limited environments