National-scale distribution of sorghum-associated protists in the leaf and root

Protists, as integral constituents of the plant microbiome, are posited to confer substantial benefits to plant health and performance. Despite their significance, protists have received considerably less attention compared to other constituents of the plant microbiome, such as bacteria and fungi. We used amplicon sequencing of the eukaryotic 18S rRNA gene in 563 leaf and root samples collected from 57 locations across China to investigate the diversity and community structure of protists in sorghum leaf and root. We found significant differences in the diversity and community structure of protists in sorghum leaf and root. The leaf was taxonomically dominated by Evosea, Cercozoa, and Ciliophora, while the root was dominated by Endomyxa, Cercozoa, and Oomycota. Protist functional taxa differed markedly between the leaf and root, with the leaf dominated by consumers and the root dominated by parasites. The community composition of protists in the leaf was mainly shaped by mean annual precipitation, compared to the dominant role of soil pH in the root. Our study identified the most abundant and distributed protists in the sorghum leaf and root, and elucidate the underlying factors that govern the architecture of their community structure. Our research offers a novel viewpoint on the determinants that shape plant-associated protist communities and their potential roles in bolstering the functionality of plant ecosystems.