Large-scale replicated field study of maize rhizosphere identifies heritable microbes

Area of Science:

• Agricultural Science
• Microbiology
• Genetics

Background:

• Understanding the root microbiome's interaction with plant genetics is crucial for crop improvement.
• Maize (Zea mays) is a globally significant crop, yet its root-associated microbial communities and their genetic regulation are not fully understood.

Purpose of the Study:

• To identify specific root-associated microbes that consistently associate with different maize genotypes.
• To determine if plant genotype influences the root microbiome independently of environmental factors.

Main Methods:

• A large-scale, longitudinal field study involving 27 maize inbred lines across three fields over five years.
• Analysis of 4,866 root-associated microbial samples using operational taxonomic units (OTUs).
• Statistical analysis to identify OTUs significantly correlated with plant genotype, accounting for age, field, and climate variations.

Main Results:

• 143 OTUs showed significant variation regulated by maize genotype, including core microbial taxa present in all samples.
• Plant genetic effects on the rhizosphere microbiome were significant, persisting despite substantial influences from plant age, field-specific microbial communities, and climate events.
• Seasonal and weather-related variations in the microbiome were observed, but specific microbial taxa consistently responded to host genotype.

Conclusions:

• Plant genotype reproducibly shapes the root microbiome in maize, independent of major environmental variables.
• Specific root-associated microbes linked to maize genotype represent potential targets for selective breeding to enhance crop traits.
• Further research into the functional roles of these genotype-associated microbes is warranted for agricultural applications.