Fig. 6
The variance of the relative abundance of the keystone and the correlation between its abundance and soil available nutrient content in ethylene addition treatments. a Layout of the exogenous ethylene addition test. Thirty grams of soil from the PRi treatment were placed in the bottom of a sterilized bottle. Then, 200 mL of 0.1 mM, 0.2 mM and 0.5 mM standard ethylene gas (ethylene and air mixed) were injected into the glass bottle (V = 100 mL) to fully replace the air. For the control (0 mM), the injection gas was replaced with air. After injection, the tubes were immediately sealed and incubated at 26 °C for 7 days for microbial community detection. b Dynamics of relative abundance of OTU235 (module hub H2 in RPi network) in different ethylene level treatments. Columns with different colours indicate significant differences (P < 0.05) according to one-way analysis of variance (ANOVA) followed by Tukey's HSD test (P < 0.05). c, d Significant relationship between OTU235 abundance and available nutrients (NH4+-N and AP) in the ethylene addition treatments (P < 0.01)