Insight into structure dynamics of soil microbiota mediated by the richness of replanted Pseudostellaria heterophylla

Abstract

Consecutive monoculture of crops causes serious diseases and significant decline in yield and quality, and microbes in the rhizosphere are closely linked with plant health. Here we systematically studied the structure dynamics of soil microbiota in the monocropping system of Pseudostellaria heterophlla. The results illustrated that the successive cropping of P. heterophylla shifts the diversity and structure of microbial community in rhizosphere soil of P. heterophylla, showing that the diversity of microbial community in rhizosphere soil of P. heterophylla was decreased with the increase of planting years while the structure of microbial community became more deteriorative. Moreover, the population size of typical pathogens increased and the beneficial bacterial population decreased with the increasing years of monoculture, which resulted in the microecological imbalance in P. heterophylla rhizosphere, thereby caused serious replanting diseases in monocropping system. Our results suggested that structure dynamics of rhizosphere microbial communities were mediated by the richness of replanted P. heterophylla, and thus the replant disease result from the imbalanced microbial structure with a higher ratio of pathogens/beneficial bacteria in rhizosphere soil under monocropping regimes. This finding provides a clue to open a new avenue for modulating the root microbiome to enhance the crop production and sustainability.

Figure 1

The Rarefaction Curve (a) and Venn Graph (b) based on 97% similarity. CK, RP, NP refer to control soil without planting any crop, newly planted soil, replanted soil, respectively. (a) Data are representative of 3 independent experiments ± s.d. The figure is representative of 3 independent experiments.

Figure 2

The Chao1 index curves (b), Shannon’s diversity index curves (c) based on 97% similarity. CK, RP, NP refer to control soil without planting any crop, newly planted soil, replanted soil, respectively. Data are representative of 3 independent experiments ± s.d. The figure is representative of 3 independent experiments.

Figure 3

The analysis of the relative abundance of bacterial phyla (a), heatmap of the dominant genera distribution (b) and Principal component analysis (PCA) (c) of the three samples. CK, RP, NP refer to control soil without planting any crop, newly planted soil, replanted soil, respectively. (a) Data are representative of 3 independent experiments ± s.d. The figure is representative of 3 independent experiments. Statistical analysis was provided by student’s t-test, where ^a,b,cP < 0.05. (b) The figure is representative of 3 independent experiments. Statistical analysis was provided by student’s t-test, where ^a,b,cP < 0.05.

Figure 4. The fungi communities DGGE banding patterns of P. hererophylla rhizosphere soil of different cropping years.

CK, RP, NP refer to control soil without planting any crop, newly planted soil, replanted soil, respectively. The figure is representative of 3 independent experiments.

Figure 5

The content of Fusaium oxysporum f. sp. hererophylla (a), Bacillus subtilis (b) and Bacillus amyloliquefaciens (c) in P. heterophylla rhizosphere soils after different years of monoculture. CK, RP, NP refer to control soil without planting any crop, newly planted soil, replanted soil, respectively. Data are representative of 4 independent experiments ± s.d. The figure is representative of 4 independent experiments. Statistical analysis was provided by student’s t-test, where ^a,b,cP < 0.05.