BayCEER Workshop 2025

Rhizosphere microbiome structure of Zea mays landraces vs. modern hybrids in two different soil types differs in response to drought

Beneficial plant–microbe interactions in the rhizosphere are key to plant resilience under environmental stress. I investigated the drought response of three traditional and three modern maize varieties in two different soils under three different irrigation strategies. Bacterial community composition was assessed using 16S rRNA gene metabarcoding. Our results revealed that soil type and rhizosphere compartment were the main determinants of microbiome structure, whereas plant genotype had little effect. Drought significantly altered microbial communities in both soil types, with pronounced shifts in bacterial taxa particularly in the rhizoplane. Enrichments of Actinobacteria, Gammaproteobacteria, and Alphaproteobacteria were observed under drought stress, with stronger effects in loamy soil. These findings suggest that soil properties and water availability outweigh maize genotype in shaping rhizosphere microbiomes, highlighting the importance of fostering beneficial microbial functions to improve crop resilience under climate change.