Figure 4. AtPP7 controls the level of phytochrome signals through NDPK2.

(A) Phenotype of psi2-DS1 (in No-0 ecotype) and ndpk2 (in Ws-2 ecotype) versus the double mutants psi2-DS1-ndpk2 under continuous white light exposure (20 µmol m⁻² s⁻¹). (B) Reversion of psi2 phenotype in the ndpk2 mutant background. Plants were exposed to continuous low fluence rate of red light (1 µmol m⁻² s⁻¹, shaded boxes) and far-red light (0.4 µmol m⁻² s⁻¹, grey boxes) for 7 days before measurement of hypocotyl elongation. Dark control: black boxes. (C) NDPK2 controls the modulation of SA-induced PR1 gene expression by light. 3 week-old plants of the described genotypes have been treated with 250 µM SA; total RNA was extracted 48 h after treatment (80 µmol m⁻² s⁻¹ white light) and used for RNA gel blot analysis. Each line contains 20 µg RNA.