Table 1.
The Effect of polδ1 Alleles on Intramolecular HRF in Plants Containing Substrates with Inverted Repeats
| Rel. HR Increase in LUC and GUS Substrates |
||||||
|---|---|---|---|---|---|---|
| polδ1 Allele | Type of Allele | HR Class | LUC | (± SEM) | GUS | (±se) |
| polδ1-1, +/− | Insertional (T-DNA) | WHR | 3.38 | (±0.27)** | 5.1 | (±0.3)** |
| polδ1-2, −/− | Insertional (T-DNA) | WHR | 2.3 | (±0.18)** | 2.5 | (±0.4)* |
| polδ1-3, +/− | Insertional (T-DNA) | WHR | 3.89 | (±0.72)** | na | – |
| RNAi-POLδ1-1 | Epigenetic (Pmas, hairpin RNA) | WHR | na | – | 5.3 | (±1.4)** |
| RNAi-POLδ1-2 | Epigenetic (Palc, hairpin RNA) | SHR | na | – | 9.6 | (±3.2)** |
| RNAi-POLδ1-3 | Epigenetic (Palc, hairpin RNA) | SHR | na | – | 47.4 | (±11.5)** |
| RNAi-POLδ1-4 | Epigenetic (Palc, hairpin RNA) | SHR | na | – | 54.1 | (±7.8)** |
| RNAi-POLδ1-5 |
Epigenetic (PU6, antisense RNA) |
SHR |
na |
– |
99.8 |
(±22.6)** |
Arabidopsis mutant plants with reduced POLδ1 expression were generated by T-DNA insertion mutagenesis or by RNAi-mediated downregulation driven by various promoter sequences (Pmas, mannopine synthase; Palc, recombinant alcohol-inducible promoter; PU6, Arabidopsis U6 snRNP promoter). The HRF of plants was assessed in the same homozygous HR substrate line IR1, and the HR increase relative to wild-type plants was calculated. Mutant alleles were classified according to their HR phenotypes: weak, WHR; strong, SHR. *, **: statistically significance level P ≤ 0.05 or P ≤ 0.01, respectively, analyzed by ANOVA (n ≥ 3 independent experiments).