Fig. 5.

The fold-change of the expression of GmPAP genes between roots with arbuscular mycorrhyza (+AM) and roots without arbuscular mycorrhyza (–AM) under low-P treatments. Soybean seeds were germinated in sand culture with or without the AM inoculants. Seven-day-old seedlings were transferred to solutions with a low concentration of P (5 µm KH₂PO₄) sand culture for 50 d before harvest. The fold-change of the expression of GmPAP genes between +AM and –AM roots was calculated (y-axis). Negative values represent higher expression of GmPAP genes in –AM roots than that of +AM roots. A threshold of 2-fold was used to determine the responsiveness of GmPAP genes in the roots to AM formation under low-P conditions. Data in the figure are the mean of four replicates ± s.e.