Table III.

Effect of NPA treatment of bean petioles on leaf blade auxin content As in Figure 4, plants with monofoliate blades 40 to 50 mm in length had one monofoliate leaf petiole treated with a 5- to 7-mm-wide band of NPA (1% [w/w] in lanolin). Leaf blades (both from treated leaves and from opposite untreated leaves) were harvested from selected plants after 24 h (1 d), 3 d, and 6 d. Free IAA was then extracted and purified by amino ion exchange column chromatography and HPLC and quantified by gas chromatography (GC)-mass spectrometry (MS)-selected ion monitoring as described below. Data are expressed as nanograms of free IAA per gram fresh wt, mean ± se.

Leaf	After Application	IAA Concentration	No. of Leaf Pairs	Significance (Paired Sample Student's t Test)
	d	ng g-1	n
Treated	1	53.2 ± 17.2	4	0.025
Untreated		29.3 ± 14.4
Treated	3	52.5 ± 11.6	3	0.076
Untreated		14.2 ± 1.4
Treated	6	8.9 ± 0.7	4	0.030
Untreated		6.3 ± 0.78