Figure 8.

Interaction between cytokinin and the GATA transcription factor genes GNL and GNC during the greening response. A and B, Analysis of transcript levels of GNL and GNC genes in 3-d-old etiolated seedlings grown on medium (MS, no Suc) with or without 1 µM BA in the dark and after 1 h exposure to light. Transcript levels of the wild type (WT) in dark were set to 1. Error bars represent se (n ≥ 3). C, Greening rate in gnl, gnc, and gnc gnl mutants grown for 3 d in dark on medium (MS, no Suc) with or without 1 µM BA. After exposure to light, chlorophyll content was measured in 3-h intervals. Diagrams shown are the average of at least three independent experiments each with three replicates per time point. One replicate consisted of 30 etiolated seedlings grown on one plate. Error bars represent se (n = 3). Letters indicate significant differences between the wild type and the different genotypes under control condition (a) or after BA treatment (b) or between control and BA treatment for each genotype (c) (P < 0.05). Asterisks above brackets indicate a significant cytokinin effect (*** P < 0.001).