Stem Endophytic Mycobiota in Wild and Domesticated Wheat: Structural Differences and Hidden Resources for Wheat Improvement

Abstract

Towards the identification of entophytic fungal taxa with potential for crop improvement, we characterized and compared fungal endophyte communities (FECs) from domesticated bread wheat and two wheat ancestors, Aegilopssharonensis and Triticumdicoccoides. Data generated by next generation sequencing identified a total of 1666 taxa. The FECs in the three plant species contained high proportions of random taxa with low abundance. At plant species level, the majority of abundant taxa were common to all host plants, and the collective FECs of each of the three plant species had similar diversity. However, FECs from the wild plants in specific sites were more diverse and had greater richness than wheat FECs from corresponding specific fields. The wild plants also had higher numbers of differentially abundant fungal taxa than wheat, with Alternaria infectoria being the most abundant species in wild plants and Candida sake the most abundant in wheat. Network analysis on co-occurrence association revealed a small number of taxa with a relatively high number of co-occurrence associations, which might be important in community assembly. Our results show that the actual endophytic cargo in cultivated wheat plants is limited relative to wild plants, and highlight putative functional and hub fungal taxa with potential for wheat improvement.

Wheat Microbiome: Structure, Dynamics, and Role in Improving Performance Under Stress Environments

“…The domestication of crops, especially wheat, has significantly disrupted the associated microbial community. Fungal endophytes exhibit more diversity and richness in wild wheat cultivars than in cultivated ones ( Sun et al, 2020 ). The D genome of hexapoloid wheat strongly favors Glomeromycetes and Nematoda ( Tkacz et al, 2020 ).…”

Seasonal Dynamics and Persistency of Endophyte Communities in Kalidium schrenkianum Shifts Under Radiation Stress

“… Buettner and Noll (2018) found few shared bacterial and archaeal OTUs in their study, indicating that the microbial communities of biogas and sewage-treated plants are distinct in community members and microbial interaction patterns. Sun et al (2020a) illustrated that certain interaction correlations are shared by co-occurrence networks from different sampling sites in wheat and other related cereal plants. Shade and Handelsman (2012) suggested that core taxa should include community members co-varying within a community and shared across communities.…”

Defining the wheat microbiome: Towards microbiome-facilitated crop production

“…Both domestication and breeding affected network topology, with microbial co-occurrence networks from landraces and tall wheat cultivars being more connected, suggesting a reduced functional redundancy in the root microbiome of modern cultivars. Fungal endophyte communities in wild wheat are richer and more diverse than in cultivated wheat, representing a greater reservoir of potentially beneficial endophytes as a higher proportion of differentially abundant taxa was found [74] . The consequences of plant breeding for the associated microbiome are not yet fully understood, however, it has been proposed that domestication has disrupted selective processes in the assembly of the wheat microbiome [71] .…”