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
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