Infection of Plasmodiophora brassicae changes the fungal endophyte community of tumourous stem mustard roots as revealed by high-throughput sequencing and culture-dependent methods

Abstract

Diverse fungal endophytes live in plants and are shaped by some abiotic and biotic stresses. Plant disease as particular biotic stress possibly gives an impact on the communities of fungal endophytes. In this study, clubroot disease caused by an obligate biotroph protist, Plasmodiophora brassicae , was considered to analyze its influence on the fungal endophyte community using an internal transcribed spacer (ITS) through high-throughput sequencing and culture-dependent methods. The results showed that the diversity of the endophyte community in the healthy roots was much higher than the clubroots. Ascomycota was the dominant group of endophytes ( Phoma , Mortierella , Penicillium , etc.) in the healthy roots while P . brassicae was the dominant taxon in the clubroots. Hierarchical clustering, principal component analysis (PCA), principal coordinates analysis (PCoA) and analysis of similarities (ANOSIM) indicated significant differences between the endophyte communities in the healthy roots and clubroots. Linear discriminant analysis effect size (LefSe) analysis showed that the dominant genera could be regarded as potential biomarkers. The endophyte community in the healthy roots had a more complex network compared with the clubroots. Also, many plant pathogenic Fusarium were isolated from the clubroots by the culture-dependent method. The outcome of this study illustrates that P . brassicae infection may change the fungal endophyte community associated with the roots of tumourous stem mustard and facilitates the entry of soil pathogen into the roots.

Trichoderma harzianum Inoculation Reduces the Incidence of Clubroot Disease in Chinese Cabbage by Regulating the Rhizosphere Microbial Community

“…A negative correlation between T. harzianum and 18 plant pathogens, including P. brassicae, Fusarium and Alternaria was found through co-occurrence network analysis ( Figure 6), which coincided with a drastic reduction in relative abundance in treated soils compared with untreated soils ( Figure 4D). Although Fusarium is a common plant pathogen in the rhizosphere [56], we did not observe significant root rot when determining the incidence of plant diseases. In conjunction with earlier reports, many Fusarium species are not pathogenic, which may be the case for the Fusarium species detected in our analysis [57].…”

Comparison of the effects of three fungicides on clubroot disease of tumorous stem mustard and soil bacterial community

“…Representative OTU sequences were obtained, and the species annotation conducted with QIIME (RDP Classifier algorithm) based on Silva database. Analysis of soil bacterial α-and β-diversity followed the methods of Tian et al (2019). Ace, Chao 1, Shannon index, Inv_Simpson index, and rarefaction curves were calculated to evaluate the α-diversity.…”

No rest for resting spores: Can predators mitigate clubroot disease?

“…In addition to direct predation on P. brassicae , predators could also suppress or enhance the clubroot disease indirectly by preying on bacteria and fungi and changing their community composition. A clubroot infection changes endophytic and rhizosphere bacterial and fungal communities (Lebreton et al, 2019; Tian et al, 2019; Wang et al, 2020). For instance, Rhodanobacter were dominant in healthy roots, and Pseudomonas dominant in clubroot (Wang et al, 2020).…”