Thiol-disulfide oxidoreductase that plays a role in proper chloroplast development, most likely through regulating plastid-encoded polymerase (PEP) dependent chloroplast transcription. Acts as a component of the transcriptionally active plastid chromosome that is required for plastid gene expression. Interacts with FLN1 and FLN2 (PubMed:20511297). Interacts with MRL7 (PubMed:23956074). Albino seedlings leading to lethality. Abnormal plastids lacking internal membrane structures. May be due to intron retention. Belongs to the thioredoxin family. Plant CITRX-type subfamily. The article has been retracted, because it has become clear that the thioredoxin that interacts in yeast 2-hybrid with the Cf-9 C-terminus is in fact localized in the chloroplast, rendering a role in Cf-9 signaling unlikely. All the authors agree that this paper should be withdrawn from the scientific literature.