Fig. 4

Root morphological traits after different microbial inoculation treatments. Schematic representation of the inoculation experiment. a Five-day-old seedlings were grown in stress-free conditions (CK) or under drought stress (polyethylene glycol [PEG 6000]) and were then either not inoculated (Control) or inoculated with rhizosphere microbiota from the YL or SQ site. b, c The bar graph shows the root length (b) and root diameter (c) of 14-day-old wheat seedlings grown in the control and SQ and YL rhizosphere microbiota groups, respectively. A difference in the lowercase letters indicates a significant difference at a probability level of P < 0.05. d, e Linear regression relationships between the relative abundance of genotype-specific keystone taxa and root length (d) or root diameter (e) after the inoculation treatments. The color of the blue dots indicates the relative abundance of the different species