Rust Disease Changes the Abundance and Composition of Bacterial Community in Iris lactea Rhizosphere

Abstract

The microbial community plays a vital role in root–environment interactions, which affect plant performance under biotic stress. Rust disease significantly affects plant growth, which may also affect rhizosphere microbial community. However, there is a scarcity of studies investigating the microbial community of rhizosphere under rust disease stress. Iris lactea is a widely utilized plant in gardening and landscaping due to its versatility and ornamental value, but it is often susceptible to rust disease in landscape settings. In this study, we compared the bacterial communities between bulk soil (non-cultivated control), rhizosphere soil of healthy Iris lactea plants, and rhizosphere soil of Iris lactea plants infected with rust disease (rhizosphere-R). Results revealed significant alterations in the abundance and composition of bacterial communities associated with rust disease infection. Specifically, the rhizosphere-R samples exhibited a decreased Shannon index at 1.9% compared to bulk soil and the relative abundance of Proteobacteria was increased at 31.65%. Moreover, distinct changes in β-diversity were shown between bulk soil and rhizosphere samples. Notably, potentially pathogenic bacteria increased in abundance under rust disease stress, while beneficial bacterial taxa decreased. Overall, our results show that rust disease affects the rhizosphere microbial community, which emphasizes the ecological implications of plant–microbe interactions under biotic stress and implications for developing targeted rhizobacterial-based biocontrol strategies.