Figure 2.

TRB4 and TRB5 are transcriptional regulators required for plant development but not for telomere protection

(A) Representative WT, trb4-1, trb5-1, trb4-2, and trb5-2 single- and double-mutant plants at 3 weeks of age.

(B) Percentage of anaphase bridges (blue line) and mean number of γH2A.X foci (histogram, red) in the WT, trb4-1 and trb5-1 single mutants, and trb4-1 trb5-1 double mutants. Plants lacking the telomerase reverse transcriptase TERT in the 9th generation (tert G9) (Fitzgerald et al., 1999) were used as a positive control of telomere deprotection. For anaphase bridges, the mean percentage of bridges observed in 100 mitoses from five individual plants and, for γH2A.X foci, the mean number of foci in 100 nuclei isolated from five individual plants from each genotype are indicated (∗∗∗p < 0.0001, t-test).

(C) TRF analysis of bulk telomere length in genomic DNA using telomere repeat probes in the WT, trb4-1 and trb5-1 single mutants, and trb4-1 trb5-1 double mutants.

(D) Representative single- and double-mutant plants at the flowering stage. Double mutants show delayed flowering and supernumerary petals (quantification in Supplemental Figure 2H and 2I).

(E) Venn diagram showing numbers of DEGs in trb4 trb5 and trb1 trb2 trb3 mutants and those common to both mutant combinations. Significance of common DEGs was determined using a hypergeometric test.

(F) GO-term enrichment of trb4 trb5 DEGs defined using ClusterProfiler.

(G) Enrichment of trb4 trb5 and trb1 trb2 trb3 DEGs in the nine CSs defined by Sequeira-Mendes et al. (2014) (∗odds ratio [OR] >1 and p < 0.05).