Abstract: Rhizosheaths can form on the surface of rice (Oryza sativa L.) roots and improve the water-use efficiency of rice under drought stress. The microbes in rhizosheaths can also offer the potential to increase the resilience of rice to future drought. However, little is known about the microbial community in rhizosheath of rice under drought stress. In this study, we compared the root traits, rhizosheath formation and microbial community in the rhizosheath under three irrigation regimes, including well-watered and drought treatments I and II. The irrigation plays important roles in influencing the microbial composition and co-occurrence networks. Drought can promote the accumulation of beneficial microorganisms in rhizosheaths, such as bacteria that are members of the phylum Patescibacteria and the Massilia, Nocardioides, Frateuria and Angustibacter genera and fungi in the genus Talaromyces. However, drought can also induce risk factors for harmful fungi in rice rhizosheaths. Our results suggest that both the rhizosheath and microbes in rhizosheath can offer the potential to improve the resistance of rice to drought. In the future, the isolation and application of beneficial microorganisms in rhizosheaths and scientific planting methods should be studied for the green cultivation of rice.

Key words: drought, rhizosheath, rice, microbial community, water-use efficiency