Moderate soil drying (MSD) is a promising agricultural technique that can reduce water consumption and enhance rhizosheath formation promoting drought resistance in plants. The endophytic fungus Piriformospora indica (P. indica) with high auxin production may be beneficial for rhizosheath formation. However, the integrated role of P. indica with native soil microbiome in rhizosheath formation is unclear. Here, we investigated the roles of P. indica and native bacteria on rice rhizosheath formation under MSD using high-throughput sequencing and rice mutants. Under MSD, rice rhizosheath formation was significantly increased by around 30% with P. indica inoculation. Auxins in rice roots and P. indica were responsible for the rhizosheath formation under MSD. Next, the abundance of the genus Bacillus, known as plant growth-promoting rhizobacteria, was enriched in the rice rhizosheath and root endosphere with P. indica inoculation under MSD. Moreover, the abundance of Bacillus cereus (B. cereus) with high auxin production was further increased by P. indica inoculation. After inoculation with both P. indica and B. cereus, rhizosheath formation in wild-type or auxin efflux carrier OsPIN2 complemented line rice was higher than that of the ospin2 mutant. Together, our results suggest that the interaction of the endophytic fungus P. indica with the native soil bacterium B. cereus favors rice rhizosheath formation by auxins modulation in rice and microbes under MSD. This finding reveals a cooperative contribution of P. indica and native microbiota in rice rhizosheath formation under moderate soil drying, which is important for improving water use in agriculture.

适度土壤干燥 (MSD) 是一种很有前途的农业技术，可以减少用水量并增强根鞘形成，促进植物的抗旱性。具有高生长素产量的内生真菌Piriformospora indica ( P. indica ) 可能有利于根鞘的形成。然而， P. indica与原生土壤微生物组在根鞘形成中的综合作用尚不清楚。在这里，我们使用高通量测序和水稻突变体研究了P. indica和本地细菌在 MSD 下水稻根鞘形成中的作用。在 MSD 下，接种P. indica后水稻根鞘的形成显着增加了约 30% 。水稻根系中的生长素和P. indica负责 MSD 下的根鞘形成。接下来，在 MSD 下接种P. indica后，芽孢杆菌属（称为植物促生长根际细菌）的丰度在水稻根鞘和根内球中得到富集。此外， P. indica接种进一步增加了具有高生长素产量的蜡状芽孢杆菌( B. cereus )的丰度。接种P. indica和B. cereus后，野生型或生长素外排载体OsPIN2互补品系水稻的根鞘形成高于ospin2变种人。总之，我们的结果表明，内生真菌P. indica与原生土壤细菌B. cereus的相互作用有利于通过 MSD 下的水稻和微生物中的生长素调节形成水稻根鞘。这一发现揭示了P. indica和本地微生物群在适度土壤干燥下对水稻根鞘形成的协同贡献，这对于改善农业用水非常重要。