Figure 5. Treatment with KH₂PO₄ alone causes depletion of other nutrients and interferes with nutrient acquisition in mycorrhizal roots.

Nutrient levels in leaves were determined 36 days after inoculation in the plants shown in Figure 3. Values are the mean of three replicates. Error bars represent standard deviations. Asterisks indicate significant differences between P_i and water treatment (a) or between mycorrhizal and non-mycorrhizal roots (b). (a) Treatment of non-inoculated plants with 5 mM KH₂PO₄ alone (black columns) compared to controls with water alone (white columns). Values are expressed relative to the water-treated controls that were set to 100% for each nutrient. (b) Nutrient content of mycorrhizal plants treated with 5 mM KH₂PO₄ (black columns) compared to non-inoculated controls treated with 5 mM KH₂PO₄ (white columns; corresponding to black columns in (a)). Values are expressed relative to the non-colonized P_i-treated controls that were set to 100% for each nutrient.