Fig. 5. Root growth phenotypes of gnom^R5 roots are auxin-mediated. (A,B) Local application of NPA at the hypocotyl-root junction of wild-type roots severely reduces lateral root formation (A) and decreases primary root elongation (B). Plants were grown for 15 days. Differences between treatments were significant (P<0.001). (C-H) Comparison of (C-E) root tips and (F-H) rosette leaves after local application of NPA. (C,F) Untreated gnom^R5, (D,G) NPA-treated wild type, (E,H) DMSO-treated wild type (control). (I) gnom^R5 root meristem collapse can be reduced by transferring seedlings to plates supplemented with NAA. Observed numbers were significantly different from each other (P<0.01). (J-L) Root regeneration of seedlings. (J) Comparison of wild-type (left) and gnom^R5 (right), 9 days after cutting. (K,L) Magnification of regeneration zone of (K) wild type and (L) gnom^R5.