Fig. 2: Effect of CO2 and nitrate levels on abundance of total bacteria per plant in roots of 6-weeks-old wheat.

Gray bars represent measurement using qPCR, where each bar represents the average of nine replicates (three biological replicates, each composed of three technical ones) with standard error. Black bars represent measurement using shotgun sequencing, where each bar represents the average of three replicates (each replicate contains a mix of three technical replicates) with standard error. Different uppercase letters indicate significant difference (P ≤ 0.05) by Student’s t test.