FIG 4 .

Topological properties of the PPI networks in the four habitats (freshwater, marine water, rhizosphere, and soil). The Pearson correlation coefficient values (r²) and probability of degree distributions P(k) (A), average clustering coefficient (B), and average neighborhood connectivity of the PPI network (C) are shown. All these properties follow the power law distribution and show the nature of scale-free network, suggesting a hierarchical organization in the network.