The Diversity and Community Composition of Three Plants' Rhizosphere Fungi in Kaolin Mining Areas

Abstract

Mining activities in the kaolin mining area have led to the disruption of the ecological health of the mining area and nearby soils, but the effects on the fungal communities in the rhizosphere soils of the plants are not clear. Three common plants (Conyza bonariensis, Artemisia annua, and Dodonaea viscosa) in kaolin mining areas were selected and analyzed their rhizosphere soil fungal communities using ITS sequencing. The alpha diversity indices (Chao1, Shannon, Simpson, observed-species, pielou-e) of the fungal communities decreased to different extents in different plants compared to the non-kauri mining area. The β-diversity (PCoA, NMDS) analysis showed that the rhizosphere soil fungal communities of the three plants in the kaolin mine area were significantly differentiated from those of the control plants grown in the non-kaolin mine area, and the extent of this differentiation varied among the plants. The analysis of fungal community composition showed that the dominant fungi in the rhizosphere fungi of C. bonariensis and A. annua changed, with an increase in the proportion of Mycosphaerella (genus) by about 20% in C. bonariensis and A. annua. An increase in the proportion of Didymella (genus) by 40% in D. viscosa was observed. At the same time, three plant rhizosphere soils were affected by kaolin mining activities with the appearance of new fungal genera Ochrocladosporium and Plenodomus. Predictive functional potential analysis of the samples revealed that a significant decrease in the potential of functions such as biosynthesis and glycolysis occurred in the rhizosphere fungal communities of kaolin-mined plants compared to non-kaolin-mined areas. The results show that heavy metals and plant species are the key factors influencing these changes, which suggests that selecting plants that can bring more abundant fungi can adapt to heavy metal contamination to restore soil ecology in the kaolin mining area.

Keywords: functional potential; fungal diversity; kaolinite; mining activities; rhizosphere fungi.

Figure 1

Rarefaction curve of different rhizosphere fungal samples based on observed_species (a) and goods_coverage (b).

Figure 2

Stacked bar chart of different rhizosphere fungi species composition of classes (a), orders (b), families (c), and genus (d).

Figure 3

Box plots of alpha diversity indices for different rhizosphere fungal samples.

Figure 4

Rank abundance curves for different plant rhizosphere fungal samples by taking the abundance of ASV as the horizontal axis and the logarithmic conversion of abundance values by Log2 as the vertical axis.

Figure 5

Principal coordinates analysis (a) and non-metric multidimensional scale analysis (b) of different plant rhizosphere fungal samples.

Figure 6

Cluster heatmap of 30 fungal genera with the highest abundance in different plant rhizosphere fungal samples.

Figure 7

Venn diagram of shared and unique ASVs between different plant rhizosphere fungal samples.

Figure 8

Manhattan plot of species composition differences between samples analyzed by metagenomeSeq. (a) Cbo vs. CK-Cbo; (b) Aan vs. CK-Aan; (c) Dvi vs. CK-Dvi. Points above the dashed line represent significant differences.

Figure 9

Relative abundance of metabolic pathways in plant rhizosphere fungi.

Figure 10

Metabolic pathways with significant Variations among different plant rhizosphere fungal samples: (a) Cbo vs. CK-Cbo; (b) Dvi vs. CK-Dvi; (c) Cbo vs. Aan; (d) Cbo vs. Dvi.