Effects of malate on the root growth of seedlings. Morphologies are shown for 6-d-old seedlings of the wild type (WT), als3, stop1, and stop1 als3 (A) and of the wild type, als3, almt1, and almt1 als3 (B) grown on +Pi and −Pi media with or without 1 mm malate. Bars = 1 cm.