Figure 4.

Auxin-deficient mutants display better root penetration ability than wild type in compacted soil. A, Phenotypes of the primary roots of 4-d-old Zhonghua 11 (ZH11, a wild-type strain), taa1, Kitaake (KT, a wild-type strain) and rein7-1 grown in uncompacted and compacted soil. Bar = 1 cm. B, Primary root length of 4-d-old ZH11, taa1, KT and rein7-1 grown in uncompacted and compacted soil. The data are shown as mean ± SD, n ≥ 30 independent seedlings. Different letters indicate significant differences (P < 0.05, one-way ANOVA with Tukey's test).