Figure 4.

Glc and BR regulation of hypocotyl elongation growth in etiolated seedlings. Quantification of hypocotyl elongation in 7-d-old etiolated wild-type (Col-0) seedlings treated without or with increasing concentrations of BR (A), increasing concentrations of Glc (B), and Glc-free medium or increased Glc concentration containing one-half-strength MS medium supplemented without or with increasing concentrations of BR (C). Glc and BR work antagonistically at lower Glc concentrations but act synergistically at higher Glc concentrations for regulation of hypocotyl elongation growth. Values represent the average from two biological replicates, each having 30 seedlings, and error bars represent se (Student’s t test, P < 0.001; *, control versus treatment).