Abstract
Plants and their associated microbiomes are impacted by environmental factors that shape their interactions over time, but long-term trends in microbial community dynamics are not well characterized. We identified the seasonal and long-term population dynamics of root-associated bacterial communities over 8 years in monocropped wheat grown in adjacent dryland and irrigated plots in the low-precipitation region of Washington State. Spring wheat plants were sampled at various times during the growing season over 8 years, and rhizosphere and endosphere communities were characterized using 16S rRNA amplicon sequencing. Analyses throughout the first 3 years revealed genera with distinct annual periodicity in response to growing season conditions. Bacterial richness and diversity were significantly greater in irrigated than in dryland wheat and in the rhizosphere than in the endosphere, apparently driven by the physiological state of the root and root exudates and/or by soil water. Over 8 years, copiotrophic Proteobacteria and Bacteroidetes ( Pseudomonas, Variovorax, Chryseobacterium) maintained stable populations, whereas Actinobacteria decreased in abundance independent of irrigation. Populations of some Bacteroidetes and Proteobacteria ( Mucilaginibacter, Sphingomonas, Massilia, Burkholderia) persisted or increased in relative abundance in the dryland rhizosphere, whereas others ( Rhizobium, Acidovorax, Terrimonas, Hyphomicrobium, Bdellovibrio) increased under irrigation. In contrast, endosphere taxa, including Actinobacteria, declined in relative abundance regardless of irrigation, indicating that the maturing host, and not water, is the main driver of these populations. Our results provide insight into the long-term dynamics of bacterial communities of wheat under contrasting soil water conditions and guide future efforts to improve crop performance under drought conditions. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 “No Rights Reserved” license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2025.
Abstract from the paper’s OpenAlex record; open copy licensed public-domain. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
Analyses of the first 3 years revealed bacterial genera with distinct annual periodicity in response to growing season conditions.
- Taxon
- Wheat
Triticum aestivumt0 - Interactor
- Bacterial Communitiest0other
- Outcome
- genera with distinct annual periodicitye0
- Qualifier
- first 3 yearse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Wheat-Associated Bacterial Communities Under Dryland and Irrigated Conditions”
e0“Analyses throughout the first 3 years revealed genera with distinct annual periodicity in response to growing season conditions”
Claim · model-written summary
Bacterial richness and diversity were significantly greater in irrigated than in dryland wheat.
- Taxon
- WheatTriticum aestivumt0
- Treatment
- irrigatede0
- Interactor
- Bacteriale0other
- Outcome
- Bacterial richness and diversitye0
- Direction
- greatere0
- Comparator
- drylande0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Wheat-Associated Bacterial Communities Under Dryland and Irrigated Conditions”
e0“Bacterial richness and diversity were significantly greater in irrigated than in dryland wheat and in the rhizosphere than in the endosphere”
Claim · model-written summary
Bacterial richness and diversity were significantly greater in the rhizosphere than in the endosphere.
- Taxon
- WheatTriticum aestivumt0
- Organ / stage
- rhizospheree0
- Interactor
- Bacteriale0other
- Outcome
- Bacterial richness and diversitye0
- Direction
- greatere0
- Comparator
- endospheree0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Wheat-Associated Bacterial Communities Under Dryland and Irrigated Conditions”
e0“Bacterial richness and diversity were significantly greater in irrigated than in dryland wheat and in the rhizosphere than in the endosphere”
Claim · model-written summary
The greater richness and diversity are apparently driven by root physiological state and exudates and/or by soil water.
- Taxon
- WheatTriticum aestivumt0
- Outcome
- Bacterial richness and diversitye0
- Qualifier
- physiological state of the root and root exudates and/or by soil watere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Wheat-Associated Bacterial Communities Under Dryland and Irrigated Conditions”
e0“Bacterial richness and diversity were significantly greater in irrigated than in dryland wheat and in the rhizosphere than in the endosphere, apparently driven by the physiological state of the root and root exudates and/or by soil water”
Claim · model-written summary
Over 8 years, Pseudomonas, Variovorax and Chryseobacterium (copiotrophic Proteobacteria and Bacteroidetes) maintained stable populations.
- Taxon
- WheatTriticum aestivumt0
- Interactor
- Pseudomonas, Variovorax, Chryseobacterium
PseudomonasVariovorax
Chryseobacteriume0other - Outcome
- stable populationse0
- Qualifier
- Over 8 yearse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Wheat-Associated Bacterial Communities Under Dryland and Irrigated Conditions”
e0“Over 8 years, copiotrophic Proteobacteria and Bacteroidetes ( Pseudomonas, Variovorax, Chryseobacterium) maintained stable populations”
Claim · model-written summary
Actinobacteria decreased in abundance over 8 years independent of irrigation.
- Taxon
- WheatTriticum aestivumt0
- Interactor
- ActinobacteriaActinomycetotae0other
- Outcome
- abundancee0
- Direction
- decreasede0
- Qualifier
- independent of irrigatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Wheat-Associated Bacterial Communities Under Dryland and Irrigated Conditions”
e0“Actinobacteria decreased in abundance independent of irrigation”
Claim · model-written summary
Mucilaginibacter, Sphingomonas, Massilia and Burkholderia persisted or increased in relative abundance in the dryland rhizosphere.
- Taxon
- WheatTriticum aestivumt0
- Organ / stage
- rhizospheree0
- Treatment
- drylande0
- Interactor
- Mucilaginibacter, Sphingomonas, Massilia, Burkholderia
Sphingomonas
Burkholderia
MassiliaMucilaginibactere0other - Outcome
- relative abundancee0
- Direction
- persisted or increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Wheat-Associated Bacterial Communities Under Dryland and Irrigated Conditions”
e0“Populations of some Bacteroidetes and Proteobacteria ( Mucilaginibacter, Sphingomonas, Massilia, Burkholderia) persisted or increased in relative abundance in the dryland rhizosphere”
Claim · model-written summary
Rhizobium, Acidovorax, Terrimonas, Hyphomicrobium and Bdellovibrio increased in relative abundance under irrigation.
- Taxon
- WheatTriticum aestivumt0
- Treatment
- irrigatione0
- Interactor
- Rhizobium, Acidovorax, Terrimonas, Hyphomicrobium, Bdellovibrio
Hyphomicrobium
Rhizobium
Bdellovibrio
AcidovoraxTerrimonase0other - Outcome
- increased under irrigatione0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Wheat-Associated Bacterial Communities Under Dryland and Irrigated Conditions”
e0“others ( Rhizobium, Acidovorax, Terrimonas, Hyphomicrobium, Bdellovibrio) increased under irrigation”
Claim · model-written summary
Endosphere taxa, including Actinobacteria, declined in relative abundance regardless of irrigation.
- Taxon
- WheatTriticum aestivumt0
- Organ / stage
- endospheree0
- Interactor
- ActinobacteriaActinomycetotae0other
- Outcome
- relative abundancee0
- Direction
- declinede0
- Qualifier
- regardless of irrigatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Wheat-Associated Bacterial Communities Under Dryland and Irrigated Conditions”
e0“In contrast, endosphere taxa, including Actinobacteria, declined in relative abundance regardless of irrigation”
Claim · model-written summary
The maturing host, and not water, is the main driver of the endosphere bacterial populations.
- Taxon
- WheatTriticum aestivumt0
- Outcome
- main driver of these populationse0
- Qualifier
- the maturing host, and not watere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Wheat-Associated Bacterial Communities Under Dryland and Irrigated Conditions”
e0“indicating that the maturing host, and not water, is the main driver of these populations”