ARFs Mediate the Al-Induced Inhibition of Root Growth.
(A) Relative primary root growth of arf mutants exposed for 7 d to either 0 or 6 μM AlCl3. Asterisks indicate that wild-type and mutant means differ significantly at **P < 0.01 and ***P < 0.001 (t test). Values represent means ± sd (n = 30).
(B) and (C) Root growth of wild-type and arf10/16 double mutant plants following a 7-d exposure to 0, 6, or 8 μM AlCl3. Asterisks in (C) indicate that wild-type and double mutant means differ significantly at **P < 0.01 and ***P < 0.001 (t test). Values in (C) represent means ± sd (n = 30).
(D) Morin staining illustrates the accumulation of Al in the root tip of 6-d-old wild-type and arf10/16 double mutant seedlings exposed to 10 μM AlCl3 for 24 h. Bar = 100 μm.
[See online article for color version of this figure.]