Fig. 1

h2a.x mutant phenotype analysis. (a) HTA.3 and HTA.5 genomic loci, showing gene structure and location of T-DNA insertions. (b) qPCR analysis of each mutant, showing cDNA-specific PCR amplification and loss of gene product in mutant seedling tissue. (c) Root hair phenotypes of wild-type (Col-0) and h2a.x mutant primary roots and length measurements in mm. Data represent mean ± SEM (n = 1,419 root hairs for Col-0 and 1,159 root hairs for h2a.x from 35 ∼ 40 roots. The asterisk (*) indicates a significant difference (Student’s t test). Scale bar, 100 μm. (d) EdU staining of WT and h2a.x double mutant roots at 3 DAG. Scale bar, 100 μm. (e) Propidium iodide (PI) staining of WT and h2a.x double mutant roots. Scale bar, 100 μm. Arrow indicates abnormal root meristematic regions in h2a.x mutants compared to WT. (f) Aberrant root growth of h2a.x mutant seedlings when grown in bleomycin MS. Root length measurements are in mm and the result of three replicate experiments, each with 15 seedlings. (g) The formation of true leaves was slightly reduced in h2a.x mutant seedlings when grown in bleomycin MS. Measurements are the result of duplicated experiments. Leaves counted are; 415 in MS only and 203 in bleomycin MS for Col-0, 395 in MS only and 209 in bleomycin MS for H2A.X internal segregated WT control, 406 in MS only and 202 in bleomycin MS for h2a.x mutant. The box height and whisker length indicate the mean and standard deviation of each sample, respectively. The significance of differences between samples was measured by the Kolmogorov–Smirnov test. Ns, not significant; * p = 0.0440