Figure 4.

Responses of roots of the wild type and aar3-1 to IBA, other classes of phytohormones, and gravity. A to E, Germinated seedlings (3 d old) were transferred to media containing IBA (A), abscisic acid (ABA; B), 6-benzyladenine (BA; C), 1-aminocyclopropane-1-carboxylic acid (ACC; D), and methyl jasmonate (Me-JA; E) and grown vertically under white light. Elongated root length was measured after 5 d of incubation. Values are expressed as a percentage of root growth without hormones for each genotype. Each data point represents the mean ± sd of 12 to 14 seedlings. F, Distribution of root growth direction of the seedlings after 3 d of stimulation at 135° to the vertical (n = 25 for the wild type and 26 for aar3-1). Three-day-old seedlings were transferred to fresh GM-MES medium, given 135° gravity stimulus, and incubated in the dark for 3 d. The arrows indicate the vector of gravity before (1) and after (2) the commencement of gravity stimulus. The angles were grouped into 12 classes and expressed as percentage in a wheel diagram. [See online article for color version of this figure.]