Composition of cercozoan diversity: Unravelling leaf, root, and soil specificity in crop plants

Protists are integral components of the plant holobiome, influencing plant growth and pathogenic pressure through their predatory activities. Wheat (Triticum aestivum), one of the most important crops globally, depends on favorable environmental conditions and effective pathogen management to achieve high yields. This study investigates the natural compositions of cercozoan diversity in winter wheat across various developmental stages (before sowing, at flowering, at ripening, and after harvesting) and plant compartments (leaves, roots, rhizosphere, and bulk soil) over two field seasons. The results revealed a pronounced dominance of the families Sandonidae, Allapsidae, Cercomonadidae, and Rhogostomidae across all samples. A strong enrichment of Sandonidae in leaf samples and Allapsidae in root samples was particularly notable. Importantly, no significant differences in cercozoan composition were observed across the different developmental stages of the plant. A comparative analysis between Triticum aestivum and Hordeum vulgare (barley) showed substantial similarity in cercozoan diversity across soil, leaf, and root compartments, with the only notable difference occurring in leaf samples during the ripening stage. The study concludes that cercozoan diversity in winter wheat is compartment-specific and remain stable across developmental stages. Further research is needed to explore cercozoan communities in greater taxonomic depth and to elucidate their ecological roles. Future studies should also assess whether similar patterns of compartmental variation and developmental consistency are observed in other major agricultural crops.