Figure 4.

Phototropism Is Dependent on Auxin Transport and PIN Auxin Efflux Facilitators.

(A) Quantification of hypocotyl bending in 5-d-old etiolated seedlings grown in the absence and presence of the auxin transport inhibitor NPA. The graphs show averages and sd of three representative experiments with at least 12 seedlings. Col, Columbia.

(B) Representative photographs of 5-d-old wild-type and pin mutant seedlings. Bar = 2 mm.

(C) Quantification of hypocotyl bending in 5-d-old etiolated pin mutant seedlings. Average and sd were determined from at least 12 seedlings. Student’s t test, compared with Columbia: *0.01 < P < 0.05; **0.001 < P<0.01; ***P < 0.001.